Sub-controllers within a webapp
Locked
Sub-controllers within a webapp
 
|
I regularly run into a situation where I need a pre-processor event to run only for a sub-set of a webapp's requests, usually within a particular group of screens (an example might be that you want to check that a specific session attribute or request parameter is set before allowing access to that set of requests). Currently you can only run an event for either a single request (request-map.event) or for every request (preprocessor.event) within a webapp, there isn't really any in-between.
I threw together a quick PoC this morning for a sub-controller implementation that would allow a webapp to have multiple controllers. Basically you have your regular controller at /control/ but within the controller.xml you can define sub-controllers and the path that it should use: Main controller.xml <sub-controller location="component://example/webapp/example/WEB-INF/sub-controller.xml" path="sub"/> now every request to /control/sub/* will use the sub-controller.xml instead of the main controller and is handled in exactly the same way as the main controller would be. Any thoughts? Thanks Scott HotWax Media http://www.hotwaxmedia.com |
smime.p7s (3K)
Re: Sub-controllers within a webapp
|
|
Re: Sub-controllers within a webapp
|
|
Hi BJ,
That could get pretty complicated (chained requests for example would make this difficult) and you'd still need to tag every request that requires a certain event to be run which would be a pain. Also preprocessor events are intended to be run on every request so I'm not sure how you'd maintain that behavior properly while enabling what you're suggesting. Thanks Scott On 16/02/2011, at 12:54 PM, BJ Freeman wrote: > how about putting a tag on the pre-processor > then include the tag in the URi spec > when the URI is accessed it uses the pre-processor in the tag. > doubt either way would make much difference at controller reload IO. > > > ========================= > BJ Freeman > Strategic Power Office with Supplier Automation <http://www.businessesnetwork.com/automation/viewforum.php?f=52> > Specialtymarket.com <http://www.specialtymarket.com/> > Systems Integrator-- Glad to Assist > > Chat Y! messenger: bjfr33man > > > Scott Gray sent the following on 2/15/2011 2:40 PM: >> I regularly run into a situation where I need a pre-processor event to run only for a sub-set of a webapp's requests, usually within a particular group of screens (an example might be that you want to check that a specific session attribute or request parameter is set before allowing access to that set of requests). Currently you can only run an event for either a single request (request-map.event) or for every request (preprocessor.event) within a webapp, there isn't really any in-between. >> >> I threw together a quick PoC this morning for a sub-controller implementation that would allow a webapp to have multiple controllers. Basically you have your regular controller at /control/ but within the controller.xml you can define sub-controllers and the path that it should use: >> Main controller.xml >> <sub-controller location="component://example/webapp/example/WEB-INF/sub-controller.xml" path="sub"/> >> now every request to /control/sub/* will use the sub-controller.xml instead of the main controller and is handled in exactly the same way as the main controller would be. >> >> Any thoughts? >> >> Thanks >> Scott >> >> HotWax Media >> http://www.hotwaxmedia.com >> > |
Re: Sub-controllers within a webapp
|
|
Re: Sub-controllers within a webapp
|
|
Re: Sub-controllers within a webapp
|
|
Re: Sub-controllers within a webapp
|
|
Re: Sub-controllers within a webapp
|
|
In my PoC implementation the sub-controller completely replaces the default ControllerConfig object during the doRequest execution so scoping isn't an issue. Basically at the very start of the doRequest method I break up the path info and then try to map the first portion to sub-controller (and then deeper if possible), once done the sub-controller gets assigned to the existing controllerConfig local variable and the request handler deals with it the same way it does now (check https, login, pre-events, request-map, post-events).
It's essentially a completely separate controller for that portion of the webapp. Regards Scott On 16/02/2011, at 7:07 PM, Adrian Crum wrote: > From my perspective, having a new element that does basically the same thing as an existing element is confusing. > > The only tricky part will be assigning the preprocessor to the correct set of requests in Java. In other words, scoping each preprocessor to a set of requests. From what I recall, the preprocessor element overwrites any included preprocessor elements. > > -Adrian > > On 2/15/2011 9:57 PM, Scott Gray wrote: >> That could be done I suppose, as long as we don't think there's much room for confusion since the two behaviors would be pretty different (include vs substitute). >> >> Regards >> Scott >> >> On 16/02/2011, at 6:05 PM, Adrian Crum<[hidden email]> wrote: >> >>> Why not add the path attribute to the existing<include> element? >>> >>> -Adrian >>> >>> On 2/15/2011 2:40 PM, Scott Gray wrote: >>>> I regularly run into a situation where I need a pre-processor event to run only for a sub-set of a webapp's requests, usually within a particular group of screens (an example might be that you want to check that a specific session attribute or request parameter is set before allowing access to that set of requests). Currently you can only run an event for either a single request (request-map.event) or for every request (preprocessor.event) within a webapp, there isn't really any in-between. >>>> >>>> I threw together a quick PoC this morning for a sub-controller implementation that would allow a webapp to have multiple controllers. Basically you have your regular controller at /control/ but within the controller.xml you can define sub-controllers and the path that it should use: >>>> Main controller.xml >>>> <sub-controller location="component://example/webapp/example/WEB-INF/sub-controller.xml" path="sub"/> >>>> now every request to /control/sub/* will use the sub-controller.xml instead of the main controller and is handled in exactly the same way as the main controller would be. >>>> >>>> Any thoughts? >>>> >>>> Thanks >>>> Scott >>>> >>>> HotWax Media >>>> http://www.hotwaxmedia.com >>>> |
Re: Sub-controllers within a webapp
|
|
Re: Sub-controllers within a webapp
|
|
Hi Jacopo,
In theory we could do that but I think it might be problematic because a developer could very easily (and unknowingly) exclude the path from any links/form targets and bypass the preprocessor. If the request uri itself is contained within a separate and distinct controller file then they could not make this mistake, they'd either get a 404 type error or they'd hit the wrong request mapping in the main controller. A possible use case for this feature could be the facility application, the screens for dealing with a single facility could be broken out into a separate sub-controller, you'd add a preprocessor that checks for a facilityId and if not present then redirects to the facility find screen. By doing this you'd never have to worry about a missing facilityId within the screens themselves. We could possibly even take it further and have sub-sessions/scopes for these types of screen groups (something like a MapStack overlaying the real session) and set the facilityId in there without it ever being carried outside of that group. Regards Scott On 16/02/2011, at 10:30 PM, Jacopo Cappellato wrote: > This is interesting, thanks Scott. > > Maybe another option could be that of adding a "condition" attribute to the pre-processor element (like path="sub"). > > Jacopo > > On Feb 15, 2011, at 11:40 PM, Scott Gray wrote: > >> I regularly run into a situation where I need a pre-processor event to run only for a sub-set of a webapp's requests, usually within a particular group of screens (an example might be that you want to check that a specific session attribute or request parameter is set before allowing access to that set of requests). Currently you can only run an event for either a single request (request-map.event) or for every request (preprocessor.event) within a webapp, there isn't really any in-between. >> >> I threw together a quick PoC this morning for a sub-controller implementation that would allow a webapp to have multiple controllers. Basically you have your regular controller at /control/ but within the controller.xml you can define sub-controllers and the path that it should use: >> Main controller.xml >> <sub-controller location="component://example/webapp/example/WEB-INF/sub-controller.xml" path="sub"/> >> now every request to /control/sub/* will use the sub-controller.xml instead of the main controller and is handled in exactly the same way as the main controller would be. >> >> Any thoughts? >> >> Thanks >> Scott >> >> HotWax Media >> http://www.hotwaxmedia.com >> > |
| Free forum by Nabble | Edit this page |