Groovy services and a DSL for OFBiz - a POC

[Jacopo Cappellato-4]

This is now fixed in rev. 1300202
By the way: we will need to carefully review the way ScriptHelper/ContextHelper are built (and especially how the context is passed) in order to make sure the code is thread safe.

Jacopo

On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:

> Ok thanks... it doesn't work for me because the scriptType is set to UNKNOWN instead of SERVICE... I am debugging it now.
>
> Jacopo
>
> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>
>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>
>> -Adrian
>>
>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>> Hey Adrian,
>>>
>>> a quick question before I dig into the details.
>>> I am using the success(..)/error(...) methods to get a result Map (for services) or result String (for Events) and I have noticed that in the new implementation they are saved using the ContextHelper.putResults method.
>>> Who is supposed to call the ContextHelper.getResults() method? It would be nice if this was done automatically by the framework (service/event handlers) rather than the script itself... but I am testing it with a service and I can't get the message back.
>>> If you could show me a code snippet it would help... if not do not worry I will figure it out.
>>>
>>> Thanks,
>>>
>>> Jacopo
>>>
>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>
>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>
>>>>>> Jacopo,
>>>>>>
>>>>>> Could you share with the rest of us the limitations caused by the refactoring?
>>>>>>
>>>>> Definitely: I will review, study and use the new code and I will provide feedback about the gaps I see.
>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>
>>>>> One thing that I am not sure I like is the fact that now some of the strings in Groovy will be expanded using the FlexibleStringExpander rather than the Groovy GStrings... this could be confusing when you are programming in Groovy.
>>>>> I was also planning to use closures to manage nicely EntityListIterators... but I can probably still do this in the GroovyBaseScript.
>>>>>
>>>>>> The work I committed is just a springboard - anyone can modify it/extend it in any way they want.
>>>>> Ok, this is good... and dangerous if anyone will add what they want without first agreeing/understanding on the purpose of this class. Do we all agree that it should stay clean and light by providing simple access for common operations rather than providing access to all the possible operations? I mean, it should provide a mechanism to perform tasks in the most common ways; for special (less frequent) tasks the calling script should use the features provided natively by the language and the standard API (delegator/dispatcher/etc...).
>>>> I agree. Let's keep the API limited to OFBiz-specific artifacts: entity engine, service engine, logging, etc.
>>>>
>>>>>> As I mentioned previously, the GroovyBaseScript class can simply delegate to the helper class:
>>>>> Yes, I will re-implement it following this design and let you know how it goes; but we will still need the Groovy service engine and Groovy event handlers... in order to keep the architecture clean should we start to think to them as extensions for the applications only? I mean that they could be part of the future release of "OFBiz Applications" and not part of the future release "OFBiz Framework". In this way the dependency and custom Groovy code will all be in the Applications (if they will be reimplemented in Groovy) and the framework will stay clean and light.
>>>> I was planning on having mini-lang's MethodContext extend ScriptHelper so all scripting languages (including mini-lang) are running on the same code base.
>>>>
>>>> I'm thinking all of this will tie up rather nicely once we have a reduced framework. Scripting can be its own component that runs on top of the new framework. Higher-level applications can then extend the scripting component
>>>>
>>>>
>>>>> Jacopo
>>>>>
>>>>>> abstract class GroovyBaseScript extends Script implements ScriptHelper {
>>>>>>   ...
>>>>>>
>>>>>>   private final ScriptHelper helper;
>>>>>>
>>>>>>   Map runService(String serviceName, Map inputMap) throws ScriptException {
>>>>>>       return helper.runService(serviceName, inputMap);
>>>>>>   }
>>>>>>
>>>>>>   Map makeValue(String entityName) throws ScriptException {
>>>>>>       return helper.makeValue(entityName);
>>>>>>   }
>>>>>>
>>>>>>   ...
>>>>>>
>>>>>> }
>>>>>>
>>>>>> -Adrian
>>>>>>
>>>>>>
>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>> Adrian, thank you for your work.
>>>>>>>
>>>>>>> What I was writing was actually an extension to Groovy for making it OFBiz friendly; now we have a "reusable" (? by other languages) version of it... my guess is that you did it because you liked the ideas in it (and I appreciate it) and you thought it was useful for other languages as well; and you may be right about this even if, as I initially mentioned, I would have preferred to complete my work, or at least add a bit more to it, test the DSL with more poc and Minilang-->Groovy conversions before crystallizing it into an interface (one of the advantages in doing it in Groovy was that I could implement it without the need to build/restart the system)... now I have an interface and an implementation of it to take care of.
>>>>>>> But I don't want to complain (*) and I will review your work closely and see what I can do to use it properly in Groovy. This refactoring has introduced a series of limitations that I am determined to resolve and it will require some more study around Groovy and ideas to cope with them... I really want that, if we will ever adopt Groovy as our next language for the applications, it will look as perfect and simple and natural and integrated as possible: the natural language for OFBiz (like Minilang is now) rather than OFBiz implemented in Groovy.
>>>>>>>
>>>>>>> But before I proceed: what is the next step in your plan? What should go in the ScriptHelper interface? Am I allowed to enhance it based on my discoveries in my poc work (Minilang-->Groovy) or should I consider it a final interface that doesn't have to be modified? Should I ask before enhancing it? I don't want to hijack your work. And more importantly: can I assume that this helper class will stay light and simple? I really don't want to see it transformed into a huge class containing a big amount of methods from different APIs... the fact that all languages will potentially use it and may wish to extend it with util methods that make sense to them concerns me a little bit (for example, a language with weak support for Map handling may need utils methods to manage Maps that could be useless for Groovy).
>>>>>>>
>>>>>>> Kind regards and again thank you,
>>>>>>>
>>>>>>> Jacopo
>>>>>>>
>>>>>>> (*) even if I find a bit annoying to see my work intercepted and re-routed while I was in the middle of it, I also appreciate the time and effort you spent on it and I really want to accept the fact that working in a community means that I have to blend and negotiate my own ideas and plans with the ones from others: sometimes it means that you get great help, sometimes it means that your own beautiful and perfect ideas are touched and rearranged to fit other's plans and other's beautiful ideas.
>>>>>>> I hope that the good attitude and flexibility I am trying to apply here will be also used by you and others when it will be time for you to accept other's proposals/changes
>>>>>>>
>>>>>>>
>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>
>>>>>>>> Jacopo,
>>>>>>>>
>>>>>>>> I committed a generic, reusable version of this idea in rev 1299924.
>>>>>>>>
>>>>>>>> -Adrian
>>>>>>>>
>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>> Hi all,
>>>>>>>>>
>>>>>>>>> I have just completed my first pass in the implementation of a DSL (Domain Specific Language) for OFBiz that can be used by Groovy services to act like a modern version of Minilang.
>>>>>>>>>
>>>>>>>>> Please review my notes here:
>>>>>>>>>
>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz
>>>>>>>>>
>>>>>>>>> I look forward to your comments and feedback but please consider that 1) it is a work in progress, 2) I spent a lot of time and mental energy in the effort (reaching simplicity is really complex task!)... so please don't be too picky :-)
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>>
>>>>>>>>> Jacopo
>>>>>>>>>
>>>>>>>>> PS: if you find it useful, I can commit the Groovy service mentioned in the page in Confluence
>

[Adrian Crum-3]

Cool - thanks! My apologies - I had not given much thought to the object
construction sequence in that section of code.

I'm pretty sure I followed good concurrency practices overall, but there
is always a chance I missed something.

-Adrian

On 3/13/2012 3:49 PM, Jacopo Cappellato wrote:

> This is now fixed in rev. 1300202
> By the way: we will need to carefully review the way ScriptHelper/ContextHelper are built (and especially how the context is passed) in order to make sure the code is thread safe.
>
> Jacopo
>
> On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:
>
>> Ok thanks... it doesn't work for me because the scriptType is set to UNKNOWN instead of SERVICE... I am debugging it now.
>>
>> Jacopo
>>
>> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>>
>>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>>
>>> -Adrian
>>>
>>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>>> Hey Adrian,
>>>>
>>>> a quick question before I dig into the details.
>>>> I am using the success(..)/error(...) methods to get a result Map (for services) or result String (for Events) and I have noticed that in the new implementation they are saved using the ContextHelper.putResults method.
>>>> Who is supposed to call the ContextHelper.getResults() method? It would be nice if this was done automatically by the framework (service/event handlers) rather than the script itself... but I am testing it with a service and I can't get the message back.
>>>> If you could show me a code snippet it would help... if not do not worry I will figure it out.
>>>>
>>>> Thanks,
>>>>
>>>> Jacopo
>>>>
>>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>>
>>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>>
>>>>>>> Jacopo,
>>>>>>>
>>>>>>> Could you share with the rest of us the limitations caused by the refactoring?
>>>>>>>
>>>>>> Definitely: I will review, study and use the new code and I will provide feedback about the gaps I see.
>>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>>
>>>>>> One thing that I am not sure I like is the fact that now some of the strings in Groovy will be expanded using the FlexibleStringExpander rather than the Groovy GStrings... this could be confusing when you are programming in Groovy.
>>>>>> I was also planning to use closures to manage nicely EntityListIterators... but I can probably still do this in the GroovyBaseScript.
>>>>>>
>>>>>>> The work I committed is just a springboard - anyone can modify it/extend it in any way they want.
>>>>>> Ok, this is good... and dangerous if anyone will add what they want without first agreeing/understanding on the purpose of this class. Do we all agree that it should stay clean and light by providing simple access for common operations rather than providing access to all the possible operations? I mean, it should provide a mechanism to perform tasks in the most common ways; for special (less frequent) tasks the calling script should use the features provided natively by the language and the standard API (delegator/dispatcher/etc...).
>>>>> I agree. Let's keep the API limited to OFBiz-specific artifacts: entity engine, service engine, logging, etc.
>>>>>
>>>>>>> As I mentioned previously, the GroovyBaseScript class can simply delegate to the helper class:
>>>>>> Yes, I will re-implement it following this design and let you know how it goes; but we will still need the Groovy service engine and Groovy event handlers... in order to keep the architecture clean should we start to think to them as extensions for the applications only? I mean that they could be part of the future release of "OFBiz Applications" and not part of the future release "OFBiz Framework". In this way the dependency and custom Groovy code will all be in the Applications (if they will be reimplemented in Groovy) and the framework will stay clean and light.
>>>>> I was planning on having mini-lang's MethodContext extend ScriptHelper so all scripting languages (including mini-lang) are running on the same code base.
>>>>>
>>>>> I'm thinking all of this will tie up rather nicely once we have a reduced framework. Scripting can be its own component that runs on top of the new framework. Higher-level applications can then extend the scripting component
>>>>>
>>>>>
>>>>>> Jacopo
>>>>>>
>>>>>>> abstract class GroovyBaseScript extends Script implements ScriptHelper {
>>>>>>>    ...
>>>>>>>
>>>>>>>    private final ScriptHelper helper;
>>>>>>>
>>>>>>>    Map runService(String serviceName, Map inputMap) throws ScriptException {
>>>>>>>        return helper.runService(serviceName, inputMap);
>>>>>>>    }
>>>>>>>
>>>>>>>    Map makeValue(String entityName) throws ScriptException {
>>>>>>>        return helper.makeValue(entityName);
>>>>>>>    }
>>>>>>>
>>>>>>>    ...
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> -Adrian
>>>>>>>
>>>>>>>
>>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>>> Adrian, thank you for your work.
>>>>>>>>
>>>>>>>> What I was writing was actually an extension to Groovy for making it OFBiz friendly; now we have a "reusable" (? by other languages) version of it... my guess is that you did it because you liked the ideas in it (and I appreciate it) and you thought it was useful for other languages as well; and you may be right about this even if, as I initially mentioned, I would have preferred to complete my work, or at least add a bit more to it, test the DSL with more poc and Minilang-->Groovy conversions before crystallizing it into an interface (one of the advantages in doing it in Groovy was that I could implement it without the need to build/restart the system)... now I have an interface and an implementation of it to take care of.
>>>>>>>> But I don't want to complain (*) and I will review your work closely and see what I can do to use it properly in Groovy. This refactoring has introduced a series of limitations that I am determined to resolve and it will require some more study around Groovy and ideas to cope with them... I really want that, if we will ever adopt Groovy as our next language for the applications, it will look as perfect and simple and natural and integrated as possible: the natural language for OFBiz (like Minilang is now) rather than OFBiz implemented in Groovy.
>>>>>>>>
>>>>>>>> But before I proceed: what is the next step in your plan? What should go in the ScriptHelper interface? Am I allowed to enhance it based on my discoveries in my poc work (Minilang-->Groovy) or should I consider it a final interface that doesn't have to be modified? Should I ask before enhancing it? I don't want to hijack your work. And more importantly: can I assume that this helper class will stay light and simple? I really don't want to see it transformed into a huge class containing a big amount of methods from different APIs... the fact that all languages will potentially use it and may wish to extend it with util methods that make sense to them concerns me a little bit (for example, a language with weak support for Map handling may need utils methods to manage Maps that could be useless for Groovy).
>>>>>>>>
>>>>>>>> Kind regards and again thank you,
>>>>>>>>
>>>>>>>> Jacopo
>>>>>>>>
>>>>>>>> (*) even if I find a bit annoying to see my work intercepted and re-routed while I was in the middle of it, I also appreciate the time and effort you spent on it and I really want to accept the fact that working in a community means that I have to blend and negotiate my own ideas and plans with the ones from others: sometimes it means that you get great help, sometimes it means that your own beautiful and perfect ideas are touched and rearranged to fit other's plans and other's beautiful ideas.
>>>>>>>> I hope that the good attitude and flexibility I am trying to apply here will be also used by you and others when it will be time for you to accept other's proposals/changes
>>>>>>>>
>>>>>>>>
>>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>>
>>>>>>>>> Jacopo,
>>>>>>>>>
>>>>>>>>> I committed a generic, reusable version of this idea in rev 1299924.
>>>>>>>>>
>>>>>>>>> -Adrian
>>>>>>>>>
>>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>>> Hi all,
>>>>>>>>>>
>>>>>>>>>> I have just completed my first pass in the implementation of a DSL (Domain Specific Language) for OFBiz that can be used by Groovy services to act like a modern version of Minilang.
>>>>>>>>>>
>>>>>>>>>> Please review my notes here:
>>>>>>>>>>
>>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz
>>>>>>>>>>
>>>>>>>>>> I look forward to your comments and feedback but please consider that 1) it is a work in progress, 2) I spent a lot of time and mental energy in the effort (reaching simplicity is really complex task!)... so please don't be too picky :-)
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>>
>>>>>>>>>> Jacopo
>>>>>>>>>>
>>>>>>>>>> PS: if you find it useful, I can commit the Groovy service mentioned in the page in Confluence

[Jacopo Cappellato-4]

Adrian,

is there a reason for invoking the script from ScriptEngine and ScriptEventHandler using:

            Object resultObj = ScriptUtil.executeScript(getLocation(modelService), modelService.invoke, scriptContext, new Object[] { context });

rather than

            Object resultObj = ScriptUtil.executeScript(getLocation(modelService), modelService.invoke, scriptContext, null);

I don't know what the args argument is used for but now we have to declare all the Groovy methods (events and services) in this way:

def setLastInventoryCount(Map notUsedInputMap) {
...
}

rather than

def setLastInventoryCount() {
...
}

and I really like the latter form because it is essential and non technical: the service/event *only* contains business rules specifications.
Any objections if I change the service/event handlers to pass a null args?

Please also see my comments inline:

On Mar 13, 2012, at 4:59 PM, Adrian Crum wrote:

> Cool - thanks! My apologies - I had not given much thought to the object construction sequence in that section of code.

Np, the code is young and I am happy to help to test/debug it.

>
> I'm pretty sure I followed good concurrency practices overall, but there is always a chance I missed something.

Ok, I didn't look enough closely at the details and in fact it may be good to go.

Jacopo

>
> -Adrian
>
> On 3/13/2012 3:49 PM, Jacopo Cappellato wrote:
>> This is now fixed in rev. 1300202
>> By the way: we will need to carefully review the way ScriptHelper/ContextHelper are built (and especially how the context is passed) in order to make sure the code is thread safe.
>>
>> Jacopo
>>
>> On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:
>>
>>> Ok thanks... it doesn't work for me because the scriptType is set to UNKNOWN instead of SERVICE... I am debugging it now.
>>>
>>> Jacopo
>>>
>>> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>>>
>>>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>>>
>>>> -Adrian
>>>>
>>>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>>>> Hey Adrian,
>>>>>
>>>>> a quick question before I dig into the details.
>>>>> I am using the success(..)/error(...) methods to get a result Map (for services) or result String (for Events) and I have noticed that in the new implementation they are saved using the ContextHelper.putResults method.
>>>>> Who is supposed to call the ContextHelper.getResults() method? It would be nice if this was done automatically by the framework (service/event handlers) rather than the script itself... but I am testing it with a service and I can't get the message back.
>>>>> If you could show me a code snippet it would help... if not do not worry I will figure it out.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Jacopo
>>>>>
>>>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>>>
>>>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>>>
>>>>>>>> Jacopo,
>>>>>>>>
>>>>>>>> Could you share with the rest of us the limitations caused by the refactoring?
>>>>>>>>
>>>>>>> Definitely: I will review, study and use the new code and I will provide feedback about the gaps I see.
>>>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>>>
>>>>>>> One thing that I am not sure I like is the fact that now some of the strings in Groovy will be expanded using the FlexibleStringExpander rather than the Groovy GStrings... this could be confusing when you are programming in Groovy.
>>>>>>> I was also planning to use closures to manage nicely EntityListIterators... but I can probably still do this in the GroovyBaseScript.
>>>>>>>
>>>>>>>> The work I committed is just a springboard - anyone can modify it/extend it in any way they want.
>>>>>>> Ok, this is good... and dangerous if anyone will add what they want without first agreeing/understanding on the purpose of this class. Do we all agree that it should stay clean and light by providing simple access for common operations rather than providing access to all the possible operations? I mean, it should provide a mechanism to perform tasks in the most common ways; for special (less frequent) tasks the calling script should use the features provided natively by the language and the standard API (delegator/dispatcher/etc...).
>>>>>> I agree. Let's keep the API limited to OFBiz-specific artifacts: entity engine, service engine, logging, etc.
>>>>>>
>>>>>>>> As I mentioned previously, the GroovyBaseScript class can simply delegate to the helper class:
>>>>>>> Yes, I will re-implement it following this design and let you know how it goes; but we will still need the Groovy service engine and Groovy event handlers... in order to keep the architecture clean should we start to think to them as extensions for the applications only? I mean that they could be part of the future release of "OFBiz Applications" and not part of the future release "OFBiz Framework". In this way the dependency and custom Groovy code will all be in the Applications (if they will be reimplemented in Groovy) and the framework will stay clean and light.
>>>>>> I was planning on having mini-lang's MethodContext extend ScriptHelper so all scripting languages (including mini-lang) are running on the same code base.
>>>>>>
>>>>>> I'm thinking all of this will tie up rather nicely once we have a reduced framework. Scripting can be its own component that runs on top of the new framework. Higher-level applications can then extend the scripting component
>>>>>>
>>>>>>
>>>>>>> Jacopo
>>>>>>>
>>>>>>>> abstract class GroovyBaseScript extends Script implements ScriptHelper {
>>>>>>>>   ...
>>>>>>>>
>>>>>>>>   private final ScriptHelper helper;
>>>>>>>>
>>>>>>>>   Map runService(String serviceName, Map inputMap) throws ScriptException {
>>>>>>>>       return helper.runService(serviceName, inputMap);
>>>>>>>>   }
>>>>>>>>
>>>>>>>>   Map makeValue(String entityName) throws ScriptException {
>>>>>>>>       return helper.makeValue(entityName);
>>>>>>>>   }
>>>>>>>>
>>>>>>>>   ...
>>>>>>>>
>>>>>>>> }
>>>>>>>>
>>>>>>>> -Adrian
>>>>>>>>
>>>>>>>>
>>>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>>>> Adrian, thank you for your work.
>>>>>>>>>
>>>>>>>>> What I was writing was actually an extension to Groovy for making it OFBiz friendly; now we have a "reusable" (? by other languages) version of it... my guess is that you did it because you liked the ideas in it (and I appreciate it) and you thought it was useful for other languages as well; and you may be right about this even if, as I initially mentioned, I would have preferred to complete my work, or at least add a bit more to it, test the DSL with more poc and Minilang-->Groovy conversions before crystallizing it into an interface (one of the advantages in doing it in Groovy was that I could implement it without the need to build/restart the system)... now I have an interface and an implementation of it to take care of.
>>>>>>>>> But I don't want to complain (*) and I will review your work closely and see what I can do to use it properly in Groovy. This refactoring has introduced a series of limitations that I am determined to resolve and it will require some more study around Groovy and ideas to cope with them... I really want that, if we will ever adopt Groovy as our next language for the applications, it will look as perfect and simple and natural and integrated as possible: the natural language for OFBiz (like Minilang is now) rather than OFBiz implemented in Groovy.
>>>>>>>>>
>>>>>>>>> But before I proceed: what is the next step in your plan? What should go in the ScriptHelper interface? Am I allowed to enhance it based on my discoveries in my poc work (Minilang-->Groovy) or should I consider it a final interface that doesn't have to be modified? Should I ask before enhancing it? I don't want to hijack your work. And more importantly: can I assume that this helper class will stay light and simple? I really don't want to see it transformed into a huge class containing a big amount of methods from different APIs... the fact that all languages will potentially use it and may wish to extend it with util methods that make sense to them concerns me a little bit (for example, a language with weak support for Map handling may need utils methods to manage Maps that could be useless for Groovy).
>>>>>>>>>
>>>>>>>>> Kind regards and again thank you,
>>>>>>>>>
>>>>>>>>> Jacopo
>>>>>>>>>
>>>>>>>>> (*) even if I find a bit annoying to see my work intercepted and re-routed while I was in the middle of it, I also appreciate the time and effort you spent on it and I really want to accept the fact that working in a community means that I have to blend and negotiate my own ideas and plans with the ones from others: sometimes it means that you get great help, sometimes it means that your own beautiful and perfect ideas are touched and rearranged to fit other's plans and other's beautiful ideas.
>>>>>>>>> I hope that the good attitude and flexibility I am trying to apply here will be also used by you and others when it will be time for you to accept other's proposals/changes
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>>>
>>>>>>>>>> Jacopo,
>>>>>>>>>>
>>>>>>>>>> I committed a generic, reusable version of this idea in rev 1299924.
>>>>>>>>>>
>>>>>>>>>> -Adrian
>>>>>>>>>>
>>>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>>>> Hi all,
>>>>>>>>>>>
>>>>>>>>>>> I have just completed my first pass in the implementation of a DSL (Domain Specific Language) for OFBiz that can be used by Groovy services to act like a modern version of Minilang.
>>>>>>>>>>>
>>>>>>>>>>> Please review my notes here:
>>>>>>>>>>>
>>>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz
>>>>>>>>>>>
>>>>>>>>>>> I look forward to your comments and feedback but please consider that 1) it is a work in progress, 2) I spent a lot of time and mental energy in the effort (reaching simplicity is really complex task!)... so please don't be too picky :-)
>>>>>>>>>>>
>>>>>>>>>>> Regards,
>>>>>>>>>>>
>>>>>>>>>>> Jacopo
>>>>>>>>>>>
>>>>>>>>>>> PS: if you find it useful, I can commit the Groovy service mentioned in the page in Confluence

[Adrian Crum-3]

The main reason is to supply a function/method argument if
modelService.invoke is not empty.

A script containing a function/method is evaluated twice - once to
evaluate the script as a whole and then again to invoke the
function/method. Any bindings that were created/used in the first
evaluation are lost in the function/method call - so the bindings are
passed as a function/method call argument.

I will update JavaScriptTest.js to illustrate the difference.

-Adrian

On 3/14/2012 5:18 AM, Jacopo Cappellato wrote:

> Adrian,
>
> is there a reason for invoking the script from ScriptEngine and ScriptEventHandler using:
>
>              Object resultObj = ScriptUtil.executeScript(getLocation(modelService), modelService.invoke, scriptContext, new Object[] { context });
>
> rather than
>
>              Object resultObj = ScriptUtil.executeScript(getLocation(modelService), modelService.invoke, scriptContext, null);
>
> I don't know what the args argument is used for but now we have to declare all the Groovy methods (events and services) in this way:
>
> def setLastInventoryCount(Map notUsedInputMap) {
> ...
> }
>
> rather than
>
> def setLastInventoryCount() {
> ...
> }
>
> and I really like the latter form because it is essential and non technical: the service/event *only* contains business rules specifications.
> Any objections if I change the service/event handlers to pass a null args?
>
> Please also see my comments inline:
>
> On Mar 13, 2012, at 4:59 PM, Adrian Crum wrote:
>
>> Cool - thanks! My apologies - I had not given much thought to the object construction sequence in that section of code.
> Np, the code is young and I am happy to help to test/debug it.
>
>> I'm pretty sure I followed good concurrency practices overall, but there is always a chance I missed something.
> Ok, I didn't look enough closely at the details and in fact it may be good to go.
>
> Jacopo
>
>> -Adrian
>>
>> On 3/13/2012 3:49 PM, Jacopo Cappellato wrote:
>>> This is now fixed in rev. 1300202
>>> By the way: we will need to carefully review the way ScriptHelper/ContextHelper are built (and especially how the context is passed) in order to make sure the code is thread safe.
>>>
>>> Jacopo
>>>
>>> On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:
>>>
>>>> Ok thanks... it doesn't work for me because the scriptType is set to UNKNOWN instead of SERVICE... I am debugging it now.
>>>>
>>>> Jacopo
>>>>
>>>> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>>>>
>>>>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>>>>
>>>>> -Adrian
>>>>>
>>>>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>>>>> Hey Adrian,
>>>>>>
>>>>>> a quick question before I dig into the details.
>>>>>> I am using the success(..)/error(...) methods to get a result Map (for services) or result String (for Events) and I have noticed that in the new implementation they are saved using the ContextHelper.putResults method.
>>>>>> Who is supposed to call the ContextHelper.getResults() method? It would be nice if this was done automatically by the framework (service/event handlers) rather than the script itself... but I am testing it with a service and I can't get the message back.
>>>>>> If you could show me a code snippet it would help... if not do not worry I will figure it out.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Jacopo
>>>>>>
>>>>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>>>>
>>>>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>>>>
>>>>>>>>> Jacopo,
>>>>>>>>>
>>>>>>>>> Could you share with the rest of us the limitations caused by the refactoring?
>>>>>>>>>
>>>>>>>> Definitely: I will review, study and use the new code and I will provide feedback about the gaps I see.
>>>>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>>>>
>>>>>>>> One thing that I am not sure I like is the fact that now some of the strings in Groovy will be expanded using the FlexibleStringExpander rather than the Groovy GStrings... this could be confusing when you are programming in Groovy.
>>>>>>>> I was also planning to use closures to manage nicely EntityListIterators... but I can probably still do this in the GroovyBaseScript.
>>>>>>>>
>>>>>>>>> The work I committed is just a springboard - anyone can modify it/extend it in any way they want.
>>>>>>>> Ok, this is good... and dangerous if anyone will add what they want without first agreeing/understanding on the purpose of this class. Do we all agree that it should stay clean and light by providing simple access for common operations rather than providing access to all the possible operations? I mean, it should provide a mechanism to perform tasks in the most common ways; for special (less frequent) tasks the calling script should use the features provided natively by the language and the standard API (delegator/dispatcher/etc...).
>>>>>>> I agree. Let's keep the API limited to OFBiz-specific artifacts: entity engine, service engine, logging, etc.
>>>>>>>
>>>>>>>>> As I mentioned previously, the GroovyBaseScript class can simply delegate to the helper class:
>>>>>>>> Yes, I will re-implement it following this design and let you know how it goes; but we will still need the Groovy service engine and Groovy event handlers... in order to keep the architecture clean should we start to think to them as extensions for the applications only? I mean that they could be part of the future release of "OFBiz Applications" and not part of the future release "OFBiz Framework". In this way the dependency and custom Groovy code will all be in the Applications (if they will be reimplemented in Groovy) and the framework will stay clean and light.
>>>>>>> I was planning on having mini-lang's MethodContext extend ScriptHelper so all scripting languages (including mini-lang) are running on the same code base.
>>>>>>>
>>>>>>> I'm thinking all of this will tie up rather nicely once we have a reduced framework. Scripting can be its own component that runs on top of the new framework. Higher-level applications can then extend the scripting component
>>>>>>>
>>>>>>>
>>>>>>>> Jacopo
>>>>>>>>
>>>>>>>>> abstract class GroovyBaseScript extends Script implements ScriptHelper {
>>>>>>>>>    ...
>>>>>>>>>
>>>>>>>>>    private final ScriptHelper helper;
>>>>>>>>>
>>>>>>>>>    Map runService(String serviceName, Map inputMap) throws ScriptException {
>>>>>>>>>        return helper.runService(serviceName, inputMap);
>>>>>>>>>    }
>>>>>>>>>
>>>>>>>>>    Map makeValue(String entityName) throws ScriptException {
>>>>>>>>>        return helper.makeValue(entityName);
>>>>>>>>>    }
>>>>>>>>>
>>>>>>>>>    ...
>>>>>>>>>
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> -Adrian
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>>>>> Adrian, thank you for your work.
>>>>>>>>>>
>>>>>>>>>> What I was writing was actually an extension to Groovy for making it OFBiz friendly; now we have a "reusable" (? by other languages) version of it... my guess is that you did it because you liked the ideas in it (and I appreciate it) and you thought it was useful for other languages as well; and you may be right about this even if, as I initially mentioned, I would have preferred to complete my work, or at least add a bit more to it, test the DSL with more poc and Minilang-->Groovy conversions before crystallizing it into an interface (one of the advantages in doing it in Groovy was that I could implement it without the need to build/restart the system)... now I have an interface and an implementation of it to take care of.
>>>>>>>>>> But I don't want to complain (*) and I will review your work closely and see what I can do to use it properly in Groovy. This refactoring has introduced a series of limitations that I am determined to resolve and it will require some more study around Groovy and ideas to cope with them... I really want that, if we will ever adopt Groovy as our next language for the applications, it will look as perfect and simple and natural and integrated as possible: the natural language for OFBiz (like Minilang is now) rather than OFBiz implemented in Groovy.
>>>>>>>>>>
>>>>>>>>>> But before I proceed: what is the next step in your plan? What should go in the ScriptHelper interface? Am I allowed to enhance it based on my discoveries in my poc work (Minilang-->Groovy) or should I consider it a final interface that doesn't have to be modified? Should I ask before enhancing it? I don't want to hijack your work. And more importantly: can I assume that this helper class will stay light and simple? I really don't want to see it transformed into a huge class containing a big amount of methods from different APIs... the fact that all languages will potentially use it and may wish to extend it with util methods that make sense to them concerns me a little bit (for example, a language with weak support for Map handling may need utils methods to manage Maps that could be useless for Groovy).
>>>>>>>>>>
>>>>>>>>>> Kind regards and again thank you,
>>>>>>>>>>
>>>>>>>>>> Jacopo
>>>>>>>>>>
>>>>>>>>>> (*) even if I find a bit annoying to see my work intercepted and re-routed while I was in the middle of it, I also appreciate the time and effort you spent on it and I really want to accept the fact that working in a community means that I have to blend and negotiate my own ideas and plans with the ones from others: sometimes it means that you get great help, sometimes it means that your own beautiful and perfect ideas are touched and rearranged to fit other's plans and other's beautiful ideas.
>>>>>>>>>> I hope that the good attitude and flexibility I am trying to apply here will be also used by you and others when it will be time for you to accept other's proposals/changes
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>>>>
>>>>>>>>>>> Jacopo,
>>>>>>>>>>>
>>>>>>>>>>> I committed a generic, reusable version of this idea in rev 1299924.
>>>>>>>>>>>
>>>>>>>>>>> -Adrian
>>>>>>>>>>>
>>>>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>>>>> Hi all,
>>>>>>>>>>>>
>>>>>>>>>>>> I have just completed my first pass in the implementation of a DSL (Domain Specific Language) for OFBiz that can be used by Groovy services to act like a modern version of Minilang.
>>>>>>>>>>>>
>>>>>>>>>>>> Please review my notes here:
>>>>>>>>>>>>
>>>>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz
>>>>>>>>>>>>
>>>>>>>>>>>> I look forward to your comments and feedback but please consider that 1) it is a work in progress, 2) I spent a lot of time and mental energy in the effort (reaching simplicity is really complex task!)... so please don't be too picky :-)
>>>>>>>>>>>>
>>>>>>>>>>>> Regards,
>>>>>>>>>>>>
>>>>>>>>>>>> Jacopo
>>>>>>>>>>>>
>>>>>>>>>>>> PS: if you find it useful, I can commit the Groovy service mentioned in the page in Confluence

[Adrian Crum-3]

Okay, I lied - the bindings are preserved between evaluations.

So go ahead and make whatever changes you need to make.

-Adrian

On 3/14/2012 5:28 AM, Adrian Crum wrote:

> The main reason is to supply a function/method argument if
> modelService.invoke is not empty.
>
> A script containing a function/method is evaluated twice - once to
> evaluate the script as a whole and then again to invoke the
> function/method. Any bindings that were created/used in the first
> evaluation are lost in the function/method call - so the bindings are
> passed as a function/method call argument.
>
> I will update JavaScriptTest.js to illustrate the difference.
>
> -Adrian
>
> On 3/14/2012 5:18 AM, Jacopo Cappellato wrote:
>> Adrian,
>>
>> is there a reason for invoking the script from ScriptEngine and
>> ScriptEventHandler using:
>>
>>              Object resultObj =
>> ScriptUtil.executeScript(getLocation(modelService),
>> modelService.invoke, scriptContext, new Object[] { context });
>>
>> rather than
>>
>>              Object resultObj =
>> ScriptUtil.executeScript(getLocation(modelService),
>> modelService.invoke, scriptContext, null);
>>
>> I don't know what the args argument is used for but now we have to
>> declare all the Groovy methods (events and services) in this way:
>>
>> def setLastInventoryCount(Map notUsedInputMap) {
>> ...
>> }
>>
>> rather than
>>
>> def setLastInventoryCount() {
>> ...
>> }
>>
>> and I really like the latter form because it is essential and non
>> technical: the service/event *only* contains business rules
>> specifications.
>> Any objections if I change the service/event handlers to pass a null
>> args?
>>
>> Please also see my comments inline:
>>
>> On Mar 13, 2012, at 4:59 PM, Adrian Crum wrote:
>>
>>> Cool - thanks! My apologies - I had not given much thought to the
>>> object construction sequence in that section of code.
>> Np, the code is young and I am happy to help to test/debug it.
>>
>>> I'm pretty sure I followed good concurrency practices overall, but
>>> there is always a chance I missed something.
>> Ok, I didn't look enough closely at the details and in fact it may be
>> good to go.
>>
>> Jacopo
>>
>>> -Adrian
>>>
>>> On 3/13/2012 3:49 PM, Jacopo Cappellato wrote:
>>>> This is now fixed in rev. 1300202
>>>> By the way: we will need to carefully review the way
>>>> ScriptHelper/ContextHelper are built (and especially how the
>>>> context is passed) in order to make sure the code is thread safe.
>>>>
>>>> Jacopo
>>>>
>>>> On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:
>>>>
>>>>> Ok thanks... it doesn't work for me because the scriptType is set
>>>>> to UNKNOWN instead of SERVICE... I am debugging it now.
>>>>>
>>>>> Jacopo
>>>>>
>>>>> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>>>>>
>>>>>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>>>>>
>>>>>> -Adrian
>>>>>>
>>>>>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>>>>>> Hey Adrian,
>>>>>>>
>>>>>>> a quick question before I dig into the details.
>>>>>>> I am using the success(..)/error(...) methods to get a result
>>>>>>> Map (for services) or result String (for Events) and I have
>>>>>>> noticed that in the new implementation they are saved using the
>>>>>>> ContextHelper.putResults method.
>>>>>>> Who is supposed to call the ContextHelper.getResults() method?
>>>>>>> It would be nice if this was done automatically by the framework
>>>>>>> (service/event handlers) rather than the script itself... but I
>>>>>>> am testing it with a service and I can't get the message back.
>>>>>>> If you could show me a code snippet it would help... if not do
>>>>>>> not worry I will figure it out.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Jacopo
>>>>>>>
>>>>>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>>>>>
>>>>>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>>>>>
>>>>>>>>>> Jacopo,
>>>>>>>>>>
>>>>>>>>>> Could you share with the rest of us the limitations caused by
>>>>>>>>>> the refactoring?
>>>>>>>>>>
>>>>>>>>> Definitely: I will review, study and use the new code and I
>>>>>>>>> will provide feedback about the gaps I see.
>>>>>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>>>>>
>>>>>>>>> One thing that I am not sure I like is the fact that now some
>>>>>>>>> of the strings in Groovy will be expanded using the
>>>>>>>>> FlexibleStringExpander rather than the Groovy GStrings... this
>>>>>>>>> could be confusing when you are programming in Groovy.
>>>>>>>>> I was also planning to use closures to manage nicely
>>>>>>>>> EntityListIterators... but I can probably still do this in the
>>>>>>>>> GroovyBaseScript.
>>>>>>>>>
>>>>>>>>>> The work I committed is just a springboard - anyone can
>>>>>>>>>> modify it/extend it in any way they want.
>>>>>>>>> Ok, this is good... and dangerous if anyone will add what they
>>>>>>>>> want without first agreeing/understanding on the purpose of
>>>>>>>>> this class. Do we all agree that it should stay clean and
>>>>>>>>> light by providing simple access for common operations rather
>>>>>>>>> than providing access to all the possible operations? I mean,
>>>>>>>>> it should provide a mechanism to perform tasks in the most
>>>>>>>>> common ways; for special (less frequent) tasks the calling
>>>>>>>>> script should use the features provided natively by the
>>>>>>>>> language and the standard API (delegator/dispatcher/etc...).
>>>>>>>> I agree. Let's keep the API limited to OFBiz-specific
>>>>>>>> artifacts: entity engine, service engine, logging, etc.
>>>>>>>>
>>>>>>>>>> As I mentioned previously, the GroovyBaseScript class can
>>>>>>>>>> simply delegate to the helper class:
>>>>>>>>> Yes, I will re-implement it following this design and let you
>>>>>>>>> know how it goes; but we will still need the Groovy service
>>>>>>>>> engine and Groovy event handlers... in order to keep the
>>>>>>>>> architecture clean should we start to think to them as
>>>>>>>>> extensions for the applications only? I mean that they could
>>>>>>>>> be part of the future release of "OFBiz Applications" and not
>>>>>>>>> part of the future release "OFBiz Framework". In this way the
>>>>>>>>> dependency and custom Groovy code will all be in the
>>>>>>>>> Applications (if they will be reimplemented in Groovy) and the
>>>>>>>>> framework will stay clean and light.
>>>>>>>> I was planning on having mini-lang's MethodContext extend
>>>>>>>> ScriptHelper so all scripting languages (including mini-lang)
>>>>>>>> are running on the same code base.
>>>>>>>>
>>>>>>>> I'm thinking all of this will tie up rather nicely once we have
>>>>>>>> a reduced framework. Scripting can be its own component that
>>>>>>>> runs on top of the new framework. Higher-level applications can
>>>>>>>> then extend the scripting component
>>>>>>>>
>>>>>>>>
>>>>>>>>> Jacopo
>>>>>>>>>
>>>>>>>>>> abstract class GroovyBaseScript extends Script implements
>>>>>>>>>> ScriptHelper {
>>>>>>>>>>    ...
>>>>>>>>>>
>>>>>>>>>>    private final ScriptHelper helper;
>>>>>>>>>>
>>>>>>>>>>    Map runService(String serviceName, Map inputMap) throws
>>>>>>>>>> ScriptException {
>>>>>>>>>>        return helper.runService(serviceName, inputMap);
>>>>>>>>>>    }
>>>>>>>>>>
>>>>>>>>>>    Map makeValue(String entityName) throws ScriptException {
>>>>>>>>>>        return helper.makeValue(entityName);
>>>>>>>>>>    }
>>>>>>>>>>
>>>>>>>>>>    ...
>>>>>>>>>>
>>>>>>>>>> }
>>>>>>>>>>
>>>>>>>>>> -Adrian
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>>>>>> Adrian, thank you for your work.
>>>>>>>>>>>
>>>>>>>>>>> What I was writing was actually an extension to Groovy for
>>>>>>>>>>> making it OFBiz friendly; now we have a "reusable" (? by
>>>>>>>>>>> other languages) version of it... my guess is that you did
>>>>>>>>>>> it because you liked the ideas in it (and I appreciate it)
>>>>>>>>>>> and you thought it was useful for other languages as well;
>>>>>>>>>>> and you may be right about this even if, as I initially
>>>>>>>>>>> mentioned, I would have preferred to complete my work, or at
>>>>>>>>>>> least add a bit more to it, test the DSL with more poc and
>>>>>>>>>>> Minilang-->Groovy conversions before crystallizing it into
>>>>>>>>>>> an interface (one of the advantages in doing it in Groovy
>>>>>>>>>>> was that I could implement it without the need to
>>>>>>>>>>> build/restart the system)... now I have an interface and an
>>>>>>>>>>> implementation of it to take care of.
>>>>>>>>>>> But I don't want to complain (*) and I will review your work
>>>>>>>>>>> closely and see what I can do to use it properly in Groovy.
>>>>>>>>>>> This refactoring has introduced a series of limitations that
>>>>>>>>>>> I am determined to resolve and it will require some more
>>>>>>>>>>> study around Groovy and ideas to cope with them... I really
>>>>>>>>>>> want that, if we will ever adopt Groovy as our next language
>>>>>>>>>>> for the applications, it will look as perfect and simple and
>>>>>>>>>>> natural and integrated as possible: the natural language for
>>>>>>>>>>> OFBiz (like Minilang is now) rather than OFBiz implemented
>>>>>>>>>>> in Groovy.
>>>>>>>>>>>
>>>>>>>>>>> But before I proceed: what is the next step in your plan?
>>>>>>>>>>> What should go in the ScriptHelper interface? Am I allowed
>>>>>>>>>>> to enhance it based on my discoveries in my poc work
>>>>>>>>>>> (Minilang-->Groovy) or should I consider it a final
>>>>>>>>>>> interface that doesn't have to be modified? Should I ask
>>>>>>>>>>> before enhancing it? I don't want to hijack your work. And
>>>>>>>>>>> more importantly: can I assume that this helper class will
>>>>>>>>>>> stay light and simple? I really don't want to see it
>>>>>>>>>>> transformed into a huge class containing a big amount of
>>>>>>>>>>> methods from different APIs... the fact that all languages
>>>>>>>>>>> will potentially use it and may wish to extend it with util
>>>>>>>>>>> methods that make sense to them concerns me a little bit
>>>>>>>>>>> (for example, a language with weak support for Map handling
>>>>>>>>>>> may need utils methods to manage Maps that could be useless
>>>>>>>>>>> for Groovy).
>>>>>>>>>>>
>>>>>>>>>>> Kind regards and again thank you,
>>>>>>>>>>>
>>>>>>>>>>> Jacopo
>>>>>>>>>>>
>>>>>>>>>>> (*) even if I find a bit annoying to see my work intercepted
>>>>>>>>>>> and re-routed while I was in the middle of it, I also
>>>>>>>>>>> appreciate the time and effort you spent on it and I really
>>>>>>>>>>> want to accept the fact that working in a community means
>>>>>>>>>>> that I have to blend and negotiate my own ideas and plans
>>>>>>>>>>> with the ones from others: sometimes it means that you get
>>>>>>>>>>> great help, sometimes it means that your own beautiful and
>>>>>>>>>>> perfect ideas are touched and rearranged to fit other's
>>>>>>>>>>> plans and other's beautiful ideas.
>>>>>>>>>>> I hope that the good attitude and flexibility I am trying to
>>>>>>>>>>> apply here will be also used by you and others when it will
>>>>>>>>>>> be time for you to accept other's proposals/changes
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Jacopo,
>>>>>>>>>>>>
>>>>>>>>>>>> I committed a generic, reusable version of this idea in rev
>>>>>>>>>>>> 1299924.
>>>>>>>>>>>>
>>>>>>>>>>>> -Adrian
>>>>>>>>>>>>
>>>>>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>>>>>> Hi all,
>>>>>>>>>>>>>
>>>>>>>>>>>>> I have just completed my first pass in the implementation
>>>>>>>>>>>>> of a DSL (Domain Specific Language) for OFBiz that can be
>>>>>>>>>>>>> used by Groovy services to act like a modern version of
>>>>>>>>>>>>> Minilang.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Please review my notes here:
>>>>>>>>>>>>>
>>>>>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz 
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> I look forward to your comments and feedback but please
>>>>>>>>>>>>> consider that 1) it is a work in progress, 2) I spent a
>>>>>>>>>>>>> lot of time and mental energy in the effort (reaching
>>>>>>>>>>>>> simplicity is really complex task!)... so please don't be
>>>>>>>>>>>>> too picky :-)
>>>>>>>>>>>>>
>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>>
>>>>>>>>>>>>> Jacopo
>>>>>>>>>>>>>
>>>>>>>>>>>>> PS: if you find it useful, I can commit the Groovy service
>>>>>>>>>>>>> mentioned in the page in Confluence

[Jacopo Cappellato-4]

Adrian, all,

I am summarizing here the results of my initial tests of the Groovy service and event executed by Adrian's  Script* classes (using JSR-223).

First of all, here are the service and events updated to work with the new code (they run with the latest enhancements I committed to framework code):

=====================================================================
import org.ofbiz.base.util.UtilDateTime
import org.ofbiz.entity.util.EntityUtil

// THIS IS A SERVICE
def setLastInventoryCount() {
    inventoryItem = ofbiz.findOne('InventoryItem')
    if (!inventoryItem) {
        ofbiz.logWarning("The InventoryItem with inventoryItemId=${parameters.inventoryItemId} doesn't exist.")
        return ofbiz.failure("Inventory item with id ${parameters.inventoryItemId} was not found.")
    }
    List productFacilities = ofbiz.findList('ProductFacility', [productId:inventoryItem.productId, facilityId:inventoryItem.facilityId])
    productFacilities.each {
        countResult = ofbiz.runService('getInventoryAvailableByFacility', [productId:it.productId, facilityId: it.facilityId])
        result = ofbiz.runService('updateProductFacility', [productId:it.productId, facilityId:it.facilityId, lastInventoryCount:countResult.availableToPromiseTotal])
    }
    return ofbiz.success("Updated inventory count for product ${inventoryItem.productId}.")
}

// THIS IS AN EVENT
def updateProductCategoryMember() {
    thruDate = parameters.thruDate
    if (!thruDate) {
        thruDate = UtilDateTime.nowTimestamp()
    }
    try {
        productCategoryMember = EntityUtil.getFirst(EntityUtil.filterByDate(ofbiz.findList('ProductCategoryMember', [productCategoryId: parameters.productCategoryId, productId: parameters.productId])))
        if (productCategoryMember) {
            productCategoryMember.setString('thruDate', thruDate)
            productCategoryMember.store()
        }
    } catch(Exception e) {
        return ofbiz.error("The following error occurred setting thruDate on category ${parameters.productCategoryId} for product ${parameters.productId}: ${e.getMessage()}")
    }
    return ofbiz.success("Set thruDate ${thruDate} on category ${parameters.productCategoryId} for product ${parameters.productId}")
}
=====================================================================

And here are some comments, each with a face to highlight the result:
:-)  good
:-/  so and so
:-( bad

* the code above is the whole content of the file I have created: as you can see is still very clear: no need to declare classes, define accessors; you simply have to write the business logic
** :-)
* after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
** :-/  (because of the small added complexity) but also :-) because now the IDE is able to autocomplete the method calls to the "ofbiz" object (with a small tweak that I will explain); this is actually a nice to have feature
* after the switch to JSR-223 the debugger of my IDE (Idea) is no more able to walk the Groovy services and events; it is working like a charm when using the Groovy specific service engine and event handler
** :-( this is really a bummer! is this only an issue with Idea? is it working with Eclipse? Need to research on this

The summary is:
* the new mechanism works fine and still allows to implement very nice services and events; this is really good
* the debug issue is rather big one (the lack of debugging tools for Minilang was one of the most frequent complains) but this is an issue that can be researched/addressed and shouldn't block the evaluation/adoption of this "new" language for services/events; even if we will fail to find a solution we could easily run the Groovy services/events using the custom engine/handler and this will not require any code change to the services/events

Next step:
it would be really nice to continue this proof of concepts by converting some interesting Java services/events and Minilang services/events to Groovy: this will help to complete the ScriptHelper classes and greatly help to appreciate pros and cons.
Is there any interest in this effort? I see a big potential in this approach, but the opinion from the community will be important.

Kind regards,

Jacopo



On Mar 13, 2012, at 4:59 PM, Adrian Crum wrote:

> Cool - thanks! My apologies - I had not given much thought to the object construction sequence in that section of code.
>
> I'm pretty sure I followed good concurrency practices overall, but there is always a chance I missed something.
>
> -Adrian
>
> On 3/13/2012 3:49 PM, Jacopo Cappellato wrote:
>> This is now fixed in rev. 1300202
>> By the way: we will need to carefully review the way ScriptHelper/ContextHelper are built (and especially how the context is passed) in order to make sure the code is thread safe.
>>
>> Jacopo
>>
>> On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:
>>
>>> Ok thanks... it doesn't work for me because the scriptType is set to UNKNOWN instead of SERVICE... I am debugging it now.
>>>
>>> Jacopo
>>>
>>> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>>>
>>>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>>>
>>>> -Adrian
>>>>
>>>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>>>> Hey Adrian,
>>>>>
>>>>> a quick question before I dig into the details.
>>>>> I am using the success(..)/error(...) methods to get a result Map (for services) or result String (for Events) and I have noticed that in the new implementation they are saved using the ContextHelper.putResults method.
>>>>> Who is supposed to call the ContextHelper.getResults() method? It would be nice if this was done automatically by the framework (service/event handlers) rather than the script itself... but I am testing it with a service and I can't get the message back.
>>>>> If you could show me a code snippet it would help... if not do not worry I will figure it out.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Jacopo
>>>>>
>>>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>>>
>>>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>>>
>>>>>>>> Jacopo,
>>>>>>>>
>>>>>>>> Could you share with the rest of us the limitations caused by the refactoring?
>>>>>>>>
>>>>>>> Definitely: I will review, study and use the new code and I will provide feedback about the gaps I see.
>>>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>>>
>>>>>>> One thing that I am not sure I like is the fact that now some of the strings in Groovy will be expanded using the FlexibleStringExpander rather than the Groovy GStrings... this could be confusing when you are programming in Groovy.
>>>>>>> I was also planning to use closures to manage nicely EntityListIterators... but I can probably still do this in the GroovyBaseScript.
>>>>>>>
>>>>>>>> The work I committed is just a springboard - anyone can modify it/extend it in any way they want.
>>>>>>> Ok, this is good... and dangerous if anyone will add what they want without first agreeing/understanding on the purpose of this class. Do we all agree that it should stay clean and light by providing simple access for common operations rather than providing access to all the possible operations? I mean, it should provide a mechanism to perform tasks in the most common ways; for special (less frequent) tasks the calling script should use the features provided natively by the language and the standard API (delegator/dispatcher/etc...).
>>>>>> I agree. Let's keep the API limited to OFBiz-specific artifacts: entity engine, service engine, logging, etc.
>>>>>>
>>>>>>>> As I mentioned previously, the GroovyBaseScript class can simply delegate to the helper class:
>>>>>>> Yes, I will re-implement it following this design and let you know how it goes; but we will still need the Groovy service engine and Groovy event handlers... in order to keep the architecture clean should we start to think to them as extensions for the applications only? I mean that they could be part of the future release of "OFBiz Applications" and not part of the future release "OFBiz Framework". In this way the dependency and custom Groovy code will all be in the Applications (if they will be reimplemented in Groovy) and the framework will stay clean and light.
>>>>>> I was planning on having mini-lang's MethodContext extend ScriptHelper so all scripting languages (including mini-lang) are running on the same code base.
>>>>>>
>>>>>> I'm thinking all of this will tie up rather nicely once we have a reduced framework. Scripting can be its own component that runs on top of the new framework. Higher-level applications can then extend the scripting component
>>>>>>
>>>>>>
>>>>>>> Jacopo
>>>>>>>
>>>>>>>> abstract class GroovyBaseScript extends Script implements ScriptHelper {
>>>>>>>>   ...
>>>>>>>>
>>>>>>>>   private final ScriptHelper helper;
>>>>>>>>
>>>>>>>>   Map runService(String serviceName, Map inputMap) throws ScriptException {
>>>>>>>>       return helper.runService(serviceName, inputMap);
>>>>>>>>   }
>>>>>>>>
>>>>>>>>   Map makeValue(String entityName) throws ScriptException {
>>>>>>>>       return helper.makeValue(entityName);
>>>>>>>>   }
>>>>>>>>
>>>>>>>>   ...
>>>>>>>>
>>>>>>>> }
>>>>>>>>
>>>>>>>> -Adrian
>>>>>>>>
>>>>>>>>
>>>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>>>> Adrian, thank you for your work.
>>>>>>>>>
>>>>>>>>> What I was writing was actually an extension to Groovy for making it OFBiz friendly; now we have a "reusable" (? by other languages) version of it... my guess is that you did it because you liked the ideas in it (and I appreciate it) and you thought it was useful for other languages as well; and you may be right about this even if, as I initially mentioned, I would have preferred to complete my work, or at least add a bit more to it, test the DSL with more poc and Minilang-->Groovy conversions before crystallizing it into an interface (one of the advantages in doing it in Groovy was that I could implement it without the need to build/restart the system)... now I have an interface and an implementation of it to take care of.
>>>>>>>>> But I don't want to complain (*) and I will review your work closely and see what I can do to use it properly in Groovy. This refactoring has introduced a series of limitations that I am determined to resolve and it will require some more study around Groovy and ideas to cope with them... I really want that, if we will ever adopt Groovy as our next language for the applications, it will look as perfect and simple and natural and integrated as possible: the natural language for OFBiz (like Minilang is now) rather than OFBiz implemented in Groovy.
>>>>>>>>>
>>>>>>>>> But before I proceed: what is the next step in your plan? What should go in the ScriptHelper interface? Am I allowed to enhance it based on my discoveries in my poc work (Minilang-->Groovy) or should I consider it a final interface that doesn't have to be modified? Should I ask before enhancing it? I don't want to hijack your work. And more importantly: can I assume that this helper class will stay light and simple? I really don't want to see it transformed into a huge class containing a big amount of methods from different APIs... the fact that all languages will potentially use it and may wish to extend it with util methods that make sense to them concerns me a little bit (for example, a language with weak support for Map handling may need utils methods to manage Maps that could be useless for Groovy).
>>>>>>>>>
>>>>>>>>> Kind regards and again thank you,
>>>>>>>>>
>>>>>>>>> Jacopo
>>>>>>>>>
>>>>>>>>> (*) even if I find a bit annoying to see my work intercepted and re-routed while I was in the middle of it, I also appreciate the time and effort you spent on it and I really want to accept the fact that working in a community means that I have to blend and negotiate my own ideas and plans with the ones from others: sometimes it means that you get great help, sometimes it means that your own beautiful and perfect ideas are touched and rearranged to fit other's plans and other's beautiful ideas.
>>>>>>>>> I hope that the good attitude and flexibility I am trying to apply here will be also used by you and others when it will be time for you to accept other's proposals/changes
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>>>
>>>>>>>>>> Jacopo,
>>>>>>>>>>
>>>>>>>>>> I committed a generic, reusable version of this idea in rev 1299924.
>>>>>>>>>>
>>>>>>>>>> -Adrian
>>>>>>>>>>
>>>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>>>> Hi all,
>>>>>>>>>>>
>>>>>>>>>>> I have just completed my first pass in the implementation of a DSL (Domain Specific Language) for OFBiz that can be used by Groovy services to act like a modern version of Minilang.
>>>>>>>>>>>
>>>>>>>>>>> Please review my notes here:
>>>>>>>>>>>
>>>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz
>>>>>>>>>>>
>>>>>>>>>>> I look forward to your comments and feedback but please consider that 1) it is a work in progress, 2) I spent a lot of time and mental energy in the effort (reaching simplicity is really complex task!)... so please don't be too picky :-)
>>>>>>>>>>>
>>>>>>>>>>> Regards,
>>>>>>>>>>>
>>>>>>>>>>> Jacopo
>>>>>>>>>>>
>>>>>>>>>>> PS: if you find it useful, I can commit the Groovy service mentioned in the page in Confluence

[Adrian Crum-3]

That's great news Jacopo! Thank you very much for working on this.

This effort will accomplish much more than just implement an OFBiz DSL -
it also opens up other interesting possibilities. For example, a user
could drop a JSR-223 PHP script engine in OFBiz and with a little
tweaking here and there, be able to use products like Drupal and Joomla
as an OFBiz front end. Also, server-side JavaScript is gaining in
popularity - which makes sense. Why have two teams of developers - one
for client-side JavaScript, and another for server-side scripting? You
can use the same tools and skill sets on both sides of the connection.

-Adrian

On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:

> Adrian, all,
>
> I am summarizing here the results of my initial tests of the Groovy service and event executed by Adrian's  Script* classes (using JSR-223).
>
> First of all, here are the service and events updated to work with the new code (they run with the latest enhancements I committed to framework code):
>
> =====================================================================
> import org.ofbiz.base.util.UtilDateTime
> import org.ofbiz.entity.util.EntityUtil
>
> // THIS IS A SERVICE
> def setLastInventoryCount() {
>      inventoryItem = ofbiz.findOne('InventoryItem')
>      if (!inventoryItem) {
>          ofbiz.logWarning("The InventoryItem with inventoryItemId=${parameters.inventoryItemId} doesn't exist.")
>          return ofbiz.failure("Inventory item with id ${parameters.inventoryItemId} was not found.")
>      }
>      List productFacilities = ofbiz.findList('ProductFacility', [productId:inventoryItem.productId, facilityId:inventoryItem.facilityId])
>      productFacilities.each {
>          countResult = ofbiz.runService('getInventoryAvailableByFacility', [productId:it.productId, facilityId: it.facilityId])
>          result = ofbiz.runService('updateProductFacility', [productId:it.productId, facilityId:it.facilityId, lastInventoryCount:countResult.availableToPromiseTotal])
>      }
>      return ofbiz.success("Updated inventory count for product ${inventoryItem.productId}.")
> }
>
> // THIS IS AN EVENT
> def updateProductCategoryMember() {
>      thruDate = parameters.thruDate
>      if (!thruDate) {
>          thruDate = UtilDateTime.nowTimestamp()
>      }
>      try {
>          productCategoryMember = EntityUtil.getFirst(EntityUtil.filterByDate(ofbiz.findList('ProductCategoryMember', [productCategoryId: parameters.productCategoryId, productId: parameters.productId])))
>          if (productCategoryMember) {
>              productCategoryMember.setString('thruDate', thruDate)
>              productCategoryMember.store()
>          }
>      } catch(Exception e) {
>          return ofbiz.error("The following error occurred setting thruDate on category ${parameters.productCategoryId} for product ${parameters.productId}: ${e.getMessage()}")
>      }
>      return ofbiz.success("Set thruDate ${thruDate} on category ${parameters.productCategoryId} for product ${parameters.productId}")
> }
> =====================================================================
>
> And here are some comments, each with a face to highlight the result:
> :-)  good
> :-/  so and so
> :-( bad
>
> * the code above is the whole content of the file I have created: as you can see is still very clear: no need to declare classes, define accessors; you simply have to write the business logic
> ** :-)
> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
> ** :-/  (because of the small added complexity) but also :-) because now the IDE is able to autocomplete the method calls to the "ofbiz" object (with a small tweak that I will explain); this is actually a nice to have feature
> * after the switch to JSR-223 the debugger of my IDE (Idea) is no more able to walk the Groovy services and events; it is working like a charm when using the Groovy specific service engine and event handler
> ** :-( this is really a bummer! is this only an issue with Idea? is it working with Eclipse? Need to research on this
>
> The summary is:
> * the new mechanism works fine and still allows to implement very nice services and events; this is really good
> * the debug issue is rather big one (the lack of debugging tools for Minilang was one of the most frequent complains) but this is an issue that can be researched/addressed and shouldn't block the evaluation/adoption of this "new" language for services/events; even if we will fail to find a solution we could easily run the Groovy services/events using the custom engine/handler and this will not require any code change to the services/events
>
> Next step:
> it would be really nice to continue this proof of concepts by converting some interesting Java services/events and Minilang services/events to Groovy: this will help to complete the ScriptHelper classes and greatly help to appreciate pros and cons.
> Is there any interest in this effort? I see a big potential in this approach, but the opinion from the community will be important.
>
> Kind regards,
>
> Jacopo
>
>
>
> On Mar 13, 2012, at 4:59 PM, Adrian Crum wrote:
>
>> Cool - thanks! My apologies - I had not given much thought to the object construction sequence in that section of code.
>>
>> I'm pretty sure I followed good concurrency practices overall, but there is always a chance I missed something.
>>
>> -Adrian
>>
>> On 3/13/2012 3:49 PM, Jacopo Cappellato wrote:
>>> This is now fixed in rev. 1300202
>>> By the way: we will need to carefully review the way ScriptHelper/ContextHelper are built (and especially how the context is passed) in order to make sure the code is thread safe.
>>>
>>> Jacopo
>>>
>>> On Mar 13, 2012, at 11:42 AM, Jacopo Cappellato wrote:
>>>
>>>> Ok thanks... it doesn't work for me because the scriptType is set to UNKNOWN instead of SERVICE... I am debugging it now.
>>>>
>>>> Jacopo
>>>>
>>>> On Mar 13, 2012, at 11:16 AM, Adrian Crum wrote:
>>>>
>>>>> org.ofbiz.service.engine.ScriptEngine.java, line 85 and below.
>>>>>
>>>>> -Adrian
>>>>>
>>>>> On 3/13/2012 10:11 AM, Jacopo Cappellato wrote:
>>>>>> Hey Adrian,
>>>>>>
>>>>>> a quick question before I dig into the details.
>>>>>> I am using the success(..)/error(...) methods to get a result Map (for services) or result String (for Events) and I have noticed that in the new implementation they are saved using the ContextHelper.putResults method.
>>>>>> Who is supposed to call the ContextHelper.getResults() method? It would be nice if this was done automatically by the framework (service/event handlers) rather than the script itself... but I am testing it with a service and I can't get the message back.
>>>>>> If you could show me a code snippet it would help... if not do not worry I will figure it out.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Jacopo
>>>>>>
>>>>>> On Mar 13, 2012, at 8:58 AM, Adrian Crum wrote:
>>>>>>
>>>>>>> On 3/13/2012 7:46 AM, Jacopo Cappellato wrote:
>>>>>>>> On Mar 13, 2012, at 7:59 AM, Adrian Crum wrote:
>>>>>>>>
>>>>>>>>> Jacopo,
>>>>>>>>>
>>>>>>>>> Could you share with the rest of us the limitations caused by the refactoring?
>>>>>>>>>
>>>>>>>> Definitely: I will review, study and use the new code and I will provide feedback about the gaps I see.
>>>>>>> Oh. I thought you were talking about the ScriptUtil refactoring.
>>>>>>>
>>>>>>>> One thing that I am not sure I like is the fact that now some of the strings in Groovy will be expanded using the FlexibleStringExpander rather than the Groovy GStrings... this could be confusing when you are programming in Groovy.
>>>>>>>> I was also planning to use closures to manage nicely EntityListIterators... but I can probably still do this in the GroovyBaseScript.
>>>>>>>>
>>>>>>>>> The work I committed is just a springboard - anyone can modify it/extend it in any way they want.
>>>>>>>> Ok, this is good... and dangerous if anyone will add what they want without first agreeing/understanding on the purpose of this class. Do we all agree that it should stay clean and light by providing simple access for common operations rather than providing access to all the possible operations? I mean, it should provide a mechanism to perform tasks in the most common ways; for special (less frequent) tasks the calling script should use the features provided natively by the language and the standard API (delegator/dispatcher/etc...).
>>>>>>> I agree. Let's keep the API limited to OFBiz-specific artifacts: entity engine, service engine, logging, etc.
>>>>>>>
>>>>>>>>> As I mentioned previously, the GroovyBaseScript class can simply delegate to the helper class:
>>>>>>>> Yes, I will re-implement it following this design and let you know how it goes; but we will still need the Groovy service engine and Groovy event handlers... in order to keep the architecture clean should we start to think to them as extensions for the applications only? I mean that they could be part of the future release of "OFBiz Applications" and not part of the future release "OFBiz Framework". In this way the dependency and custom Groovy code will all be in the Applications (if they will be reimplemented in Groovy) and the framework will stay clean and light.
>>>>>>> I was planning on having mini-lang's MethodContext extend ScriptHelper so all scripting languages (including mini-lang) are running on the same code base.
>>>>>>>
>>>>>>> I'm thinking all of this will tie up rather nicely once we have a reduced framework. Scripting can be its own component that runs on top of the new framework. Higher-level applications can then extend the scripting component
>>>>>>>
>>>>>>>
>>>>>>>> Jacopo
>>>>>>>>
>>>>>>>>> abstract class GroovyBaseScript extends Script implements ScriptHelper {
>>>>>>>>>    ...
>>>>>>>>>
>>>>>>>>>    private final ScriptHelper helper;
>>>>>>>>>
>>>>>>>>>    Map runService(String serviceName, Map inputMap) throws ScriptException {
>>>>>>>>>        return helper.runService(serviceName, inputMap);
>>>>>>>>>    }
>>>>>>>>>
>>>>>>>>>    Map makeValue(String entityName) throws ScriptException {
>>>>>>>>>        return helper.makeValue(entityName);
>>>>>>>>>    }
>>>>>>>>>
>>>>>>>>>    ...
>>>>>>>>>
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> -Adrian
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 3/13/2012 5:49 AM, Jacopo Cappellato wrote:
>>>>>>>>>> Adrian, thank you for your work.
>>>>>>>>>>
>>>>>>>>>> What I was writing was actually an extension to Groovy for making it OFBiz friendly; now we have a "reusable" (? by other languages) version of it... my guess is that you did it because you liked the ideas in it (and I appreciate it) and you thought it was useful for other languages as well; and you may be right about this even if, as I initially mentioned, I would have preferred to complete my work, or at least add a bit more to it, test the DSL with more poc and Minilang-->Groovy conversions before crystallizing it into an interface (one of the advantages in doing it in Groovy was that I could implement it without the need to build/restart the system)... now I have an interface and an implementation of it to take care of.
>>>>>>>>>> But I don't want to complain (*) and I will review your work closely and see what I can do to use it properly in Groovy. This refactoring has introduced a series of limitations that I am determined to resolve and it will require some more study around Groovy and ideas to cope with them... I really want that, if we will ever adopt Groovy as our next language for the applications, it will look as perfect and simple and natural and integrated as possible: the natural language for OFBiz (like Minilang is now) rather than OFBiz implemented in Groovy.
>>>>>>>>>>
>>>>>>>>>> But before I proceed: what is the next step in your plan? What should go in the ScriptHelper interface? Am I allowed to enhance it based on my discoveries in my poc work (Minilang-->Groovy) or should I consider it a final interface that doesn't have to be modified? Should I ask before enhancing it? I don't want to hijack your work. And more importantly: can I assume that this helper class will stay light and simple? I really don't want to see it transformed into a huge class containing a big amount of methods from different APIs... the fact that all languages will potentially use it and may wish to extend it with util methods that make sense to them concerns me a little bit (for example, a language with weak support for Map handling may need utils methods to manage Maps that could be useless for Groovy).
>>>>>>>>>>
>>>>>>>>>> Kind regards and again thank you,
>>>>>>>>>>
>>>>>>>>>> Jacopo
>>>>>>>>>>
>>>>>>>>>> (*) even if I find a bit annoying to see my work intercepted and re-routed while I was in the middle of it, I also appreciate the time and effort you spent on it and I really want to accept the fact that working in a community means that I have to blend and negotiate my own ideas and plans with the ones from others: sometimes it means that you get great help, sometimes it means that your own beautiful and perfect ideas are touched and rearranged to fit other's plans and other's beautiful ideas.
>>>>>>>>>> I hope that the good attitude and flexibility I am trying to apply here will be also used by you and others when it will be time for you to accept other's proposals/changes
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Mar 13, 2012, at 12:35 AM, Adrian Crum wrote:
>>>>>>>>>>
>>>>>>>>>>> Jacopo,
>>>>>>>>>>>
>>>>>>>>>>> I committed a generic, reusable version of this idea in rev 1299924.
>>>>>>>>>>>
>>>>>>>>>>> -Adrian
>>>>>>>>>>>
>>>>>>>>>>> On 3/8/2012 6:02 PM, Jacopo Cappellato wrote:
>>>>>>>>>>>> Hi all,
>>>>>>>>>>>>
>>>>>>>>>>>> I have just completed my first pass in the implementation of a DSL (Domain Specific Language) for OFBiz that can be used by Groovy services to act like a modern version of Minilang.
>>>>>>>>>>>>
>>>>>>>>>>>> Please review my notes here:
>>>>>>>>>>>>
>>>>>>>>>>>> https://cwiki.apache.org/confluence/display/OFBIZ/Groovy+Services+and+DSL+for+OFBiz
>>>>>>>>>>>>
>>>>>>>>>>>> I look forward to your comments and feedback but please consider that 1) it is a work in progress, 2) I spent a lot of time and mental energy in the effort (reaching simplicity is really complex task!)... so please don't be too picky :-)
>>>>>>>>>>>>
>>>>>>>>>>>> Regards,
>>>>>>>>>>>>
>>>>>>>>>>>> Jacopo
>>>>>>>>>>>>
>>>>>>>>>>>> PS: if you find it useful, I can commit the Groovy service mentioned in the page in Confluence

[Adrian Crum-3]

On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:
> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)

You could implement your own script engine factory to enable the
extended Script class + DSL idea (GroovyBaseScript).

-Adrian

[Jacopo Cappellato-4]

On Mar 14, 2012, at 9:23 AM, Adrian Crum wrote:

> On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:
>> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
>
> You could implement your own script engine factory to enable the extended Script class + DSL idea (GroovyBaseScript).

Yes, this is what I meant... however I think it is fine to keep the "ofbiz." syntax for now and see how it goes (the switch in the future would be a matter of a few search-and-replace operations).
Actually a more compelling reason for using a custom engine would be to enable debugging... but even if we decide to do this I would prefer to continue to use the "ofbiz." syntax (i.e. do not inject the GroovyBaseScript)... in this way the decision engine switch will not affect in any way the code in the scripts. When everything will be consolidated it will be easier to see what the is the best way to go.

Jacopo

>
> -Adrian
>

[Adrian Crum-3]

Speaking of consolidation, once I have the mini-language grammar
finalized, I will have mini-language implement JSR-223 so that it can be
run in the same generic way. Then we will be able to remove a some of
the mini-language specific classes (service/event engines).

-Adrian

On 3/14/2012 8:29 AM, Jacopo Cappellato wrote:

> On Mar 14, 2012, at 9:23 AM, Adrian Crum wrote:
>
>> On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:
>>> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
>> You could implement your own script engine factory to enable the extended Script class + DSL idea (GroovyBaseScript).
> Yes, this is what I meant... however I think it is fine to keep the "ofbiz." syntax for now and see how it goes (the switch in the future would be a matter of a few search-and-replace operations).
> Actually a more compelling reason for using a custom engine would be to enable debugging... but even if we decide to do this I would prefer to continue to use the "ofbiz." syntax (i.e. do not inject the GroovyBaseScript)... in this way the decision engine switch will not affect in any way the code in the scripts. When everything will be consolidated it will be easier to see what the is the best way to go.
>
> Jacopo
>
>> -Adrian
>>

[Jacopo Cappellato-4]

This is nice.
It would be also nice to move Minilang framework code out of the OFBiz framework to become a separate project for the language itself (and "OFBiz applications" could use it as they use Groovy); but I know this will be impossible because of the dependencies on OFBiz services/delegator.

Jacopo

On Mar 14, 2012, at 9:34 AM, Adrian Crum wrote:

> Speaking of consolidation, once I have the mini-language grammar finalized, I will have mini-language implement JSR-223 so that it can be run in the same generic way. Then we will be able to remove a some of the mini-language specific classes (service/event engines).
>
> -Adrian
>
> On 3/14/2012 8:29 AM, Jacopo Cappellato wrote:
>> On Mar 14, 2012, at 9:23 AM, Adrian Crum wrote:
>>
>>> On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:
>>>> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
>>> You could implement your own script engine factory to enable the extended Script class + DSL idea (GroovyBaseScript).
>> Yes, this is what I meant... however I think it is fine to keep the "ofbiz." syntax for now and see how it goes (the switch in the future would be a matter of a few search-and-replace operations).
>> Actually a more compelling reason for using a custom engine would be to enable debugging... but even if we decide to do this I would prefer to continue to use the "ofbiz." syntax (i.e. do not inject the GroovyBaseScript)... in this way the decision engine switch will not affect in any way the code in the scripts. When everything will be consolidated it will be easier to see what the is the best way to go.
>>
>> Jacopo
>>
>>> -Adrian
>>>

[Scott Gray-2]

Apache Jelly is probably the project you're looking to create :-)
http://commons.apache.org/jelly/

Regards
Scott

On 14/03/2012, at 9:49 PM, Jacopo Cappellato wrote:

> This is nice.
> It would be also nice to move Minilang framework code out of the OFBiz framework to become a separate project for the language itself (and "OFBiz applications" could use it as they use Groovy); but I know this will be impossible because of the dependencies on OFBiz services/delegator.
>
> Jacopo
>
> On Mar 14, 2012, at 9:34 AM, Adrian Crum wrote:
>
>> Speaking of consolidation, once I have the mini-language grammar finalized, I will have mini-language implement JSR-223 so that it can be run in the same generic way. Then we will be able to remove a some of the mini-language specific classes (service/event engines).
>>
>> -Adrian
>>
>> On 3/14/2012 8:29 AM, Jacopo Cappellato wrote:
>>> On Mar 14, 2012, at 9:23 AM, Adrian Crum wrote:
>>>
>>>> On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:
>>>>> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
>>>> You could implement your own script engine factory to enable the extended Script class + DSL idea (GroovyBaseScript).
>>> Yes, this is what I meant... however I think it is fine to keep the "ofbiz." syntax for now and see how it goes (the switch in the future would be a matter of a few search-and-replace operations).
>>> Actually a more compelling reason for using a custom engine would be to enable debugging... but even if we decide to do this I would prefer to continue to use the "ofbiz." syntax (i.e. do not inject the GroovyBaseScript)... in this way the decision engine switch will not affect in any way the code in the scripts. When everything will be consolidated it will be easier to see what the is the best way to go.
>>>
>>> Jacopo
>>>
>>>> -Adrian
>>>>
>

[Adrian Crum-3]

Actually, it is impossible because a lot of framework code depends on
mini-language.

-Adrian

On 3/14/2012 8:49 AM, Jacopo Cappellato wrote:

> This is nice.
> It would be also nice to move Minilang framework code out of the OFBiz framework to become a separate project for the language itself (and "OFBiz applications" could use it as they use Groovy); but I know this will be impossible because of the dependencies on OFBiz services/delegator.
>
> Jacopo
>
> On Mar 14, 2012, at 9:34 AM, Adrian Crum wrote:
>
>> Speaking of consolidation, once I have the mini-language grammar finalized, I will have mini-language implement JSR-223 so that it can be run in the same generic way. Then we will be able to remove a some of the mini-language specific classes (service/event engines).
>>
>> -Adrian
>>
>> On 3/14/2012 8:29 AM, Jacopo Cappellato wrote:
>>> On Mar 14, 2012, at 9:23 AM, Adrian Crum wrote:
>>>
>>>> On 3/14/2012 7:56 AM, Jacopo Cappellato wrote:
>>>>> * after the switch to JSR-223 the "DSL method" are accessed thru the "ofbiz" reference (instead of being directly available as method calls)
>>>> You could implement your own script engine factory to enable the extended Script class + DSL idea (GroovyBaseScript).
>>> Yes, this is what I meant... however I think it is fine to keep the "ofbiz." syntax for now and see how it goes (the switch in the future would be a matter of a few search-and-replace operations).
>>> Actually a more compelling reason for using a custom engine would be to enable debugging... but even if we decide to do this I would prefer to continue to use the "ofbiz." syntax (i.e. do not inject the GroovyBaseScript)... in this way the decision engine switch will not affect in any way the code in the scripts. When everything will be consolidated it will be easier to see what the is the best way to go.
>>>
>>> Jacopo
>>>
>>>> -Adrian
>>>>

[Anne Jessel]

I go away for a few days, and you drop the DSL idea and replace it with an
old-fashioned language-agnostic helper class. I don't have a problem with
that. It gives up the ability to develop a nice DSL which would necessarily
be groovy based, but replaces it with the advantage of being able to use
almost any scripting language (but without direct DSL support).

Maybe once the helper class is mature, there won't be much point creating a
DSL. If there is still a point, a DSL probably would be easier to create
using the helper class.

Unfortunately I don't have time to help much with this effort at the
moment, although I would really like to. I'll try to at least grab the
changes soon and play with them, so I can give feedback.

I do think it critical that the debugger works. The editing aids my editor
gives me for groovy must also work. These are the two biggest issues with
minilang, and why I no longer use minilang except for the simplest services.

+1 to Jacopo's suggestion to concentrate on implementing what is actually
used, and not what one thinks might be useful.

Good work, everyone (especially Jacopo and Adrian).

Cheers,
Anne.

--
Coherent Software Australia Pty Ltd
PO Box 2773
Cheltenham Vic 3192
Phone: [phone]
Fax: [phone]
Web: http://www.cohsoft.com.au/
Email: [hidden email]

Bonsai ERP, the all-inclusive ERP system
http://www.bonsaierp.com.au/

[Jacopo Cappellato-4]

On Mar 15, 2012, at 1:40 AM, Anne wrote:

> I go away for a few days, and you drop the DSL idea and replace it with an
> old-fashioned language-agnostic helper class.

:-)

Anne, I must admit that I had the same reaction at the beginning, but in a community you have to blend your plans/ideas with the ones from others if they have strong opinions on them. I also accepted to see my work being re-routed when I realized we could still implement Groovy services and events in a very nice way: if you review the "new" version of my services/events, apart from the ugly "ofbiz." prefix, all the important things are exactly the same.
So for now we can use this work assuming we have at disposal a nice language: Groovy powered by an OFBiz DSL
I have the following short term plans:
* we will expand the DSL (i.e. the helper class) a little bit in order to provide a couple more frequently used operations
* I will keep a close eye at the way the "helper" class evolves in order to avoid the risk of seeing it become another ugly complex api
* at some point we may decide to wrap it into a Groovy friendly class to enable full DSL
* we have also some plans to implement a Groovy builder for complex dynamic view entities or entity queries: this would complete the DSL for Groovy (if possible we will implement it in a Java friendly way, but if not it will be a Groovy only thing)
Then the "OFBiz applications" will have a great language to migrate to (if the community will see the benefit of migrating the existing "application" code from Java and Minilang to the new Groovy) or simply to use it for new development.

Jacopo

[Anne Jessel]

On 15 March 2012 16:37, Jacopo Cappellato <[hidden email]
> wrote:

> On Mar 15, 2012, at 1:40 AM, Anne wrote:
>
> > I go away for a few days, and you drop the DSL idea and replace it with
> an
> > old-fashioned language-agnostic helper class.
>
> :-)
>
> Anne, I must admit that I had the same reaction at the beginning, but in a
> community you have to blend your plans/ideas with the ones from others if
> they have strong opinions on them.

Yes, Jacopo, I agree. Way I see it, if the community decides to do
something I don't want (which isn't the case here!) I have two choices. I
can silently live with it, or silently leave.

I am happy with the helper class, just not as happy as I was when I thought
a DSL was being developed. The helper class is a big improvement over the
current system, and I am pleased it exists.

I also accepted to see my work being re-routed when I realized we could
> still implement Groovy services and events in a very nice way: if you
> review the "new" version of my services/events, apart from the ugly
> "ofbiz." prefix, all the important things are exactly the same.
>

That is good to hear, though it is the possible directions the DSL could
have gone in the future that I was looking forward to, rather than what had
already been achieved.

> I have the following short term plans:
> * we will expand the DSL (i.e. the helper class) a little bit in order to
> provide a couple more frequently used operations
> * I will keep a close eye at the way the "helper" class evolves in order
> to avoid the risk of seeing it become another ugly complex api
> * at some point we may decide to wrap it into a Groovy friendly class to
> enable full DSL
> * we have also some plans to implement a Groovy builder for complex
> dynamic view entities or entity queries: this would complete the DSL for
> Groovy (if possible we will implement it in a Java friendly way, but if not
> it will be a Groovy only thing)
>

+1 to all of this.

Cheers,
Anne.

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