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Posted to users@tapestry.apache.org by Peter Stavrinides <p....@albourne.com> on 2006/11/15 11:25:24 UTC
ASO Injection Question
What is the best approach for the following scenario:
I have a listener class that listens for session activity, its
configured only in my web.xml (not for instance in hivemind)
I have a state object that I need to inject into the listener class, but
since I cannot make the listener class abstract how will I inject my
state object? or what can I do otherwise?
Thanks
Peter
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Re: ASO Injection Question
Posted by Peter Stavrinides <p....@albourne.com>.
Thanks so much!
Richard Kirby wrote:
> Hi Peter,
>
> State objects are not the same as HiveMind services. So reg.getService
> will return a service you have defined with <service-point /> in a
> hivemodule.xml. However these are typically equivalent to singletons
> and therefore shared across all sessions. A state object is managed by
> the ApplicationStateManager and can be either a global object (in many
> ways a HiveMind service is equivalent), or a session object which is
> per user web session.
>
> Note that you only need to get the ApplicationStateManager object once
> (use lazy initialization), as it will last for the lifetime of the web
> application, so something like:
>
> class MySessionListener implements HttpSessionListener {
> private ApplicationStateManager asm;
>
> public void sessionCreated(HttpSessionEvent event) {
> if (asm == null) {
> Registry reg =
> (Registry)event.getSession().getServletContext().getAttribute("org.apache.tapestry.Registry:IRM");
>
> asm =
> (ApplicationStateManager)reg.getService(ApplicationStateManager.class);
> }
>
> Visit visit = (Visit)asm.get("visit");
> // do stuff
> }
> }
>
> Cheers
>
> Richard
>
> Peter Stavrinides wrote:
>> Thanks Richard, this is truly a bit of magic, one question though
>> regarding the last step:
>>
>> Is there any reason why I would need to use the
>> ApplicationStateManager object, can I rather access a service
>> directly using getService() ?
>>
>> For instance, I get the registry like so:
>> Registry reg = (Registry)
>> event.getSession().getServletContext().getAttribute("org.apache.tapestry.Registry:IRM");
>> //where IRM is the name of the servlet
>>
>> and then use something like:
>> reg.getService(Visit.class);
>>
>> Thanks again,
>> Peter
>>
>> Richard Kirby wrote:
>>> Hi Peter,
>>>
>>> One way of doing this is to access the HiveMind Registry object that
>>> Tapestry creates, from within your listener class, so that you can
>>> then access the ApplicationStateManager, and from that access your ASO.
>>>
>>> However, you have to use a little magic to access the Registry object:
>>>
>>> 1. From the sessionCreated/sessionDestroyed method you have access
>>> to the HttpSessionEvent object.
>>> 2. From the HttpSessionEvent object you have access to the
>>> HttpSession object.
>>> 3. From the HttpSession object you have access to the ServletContext
>>> 4. From the ServletContext object you can look up the HiveMind
>>> Registry using the getAttribute method with the key
>>> "org.apache.tapestry.Registry:SERVLET_NAME" where SERVLET_NAME is
>>> the name of the Tapestry application servlet you have specified in
>>> your web.xml (this is the magic bit since it requires knowing how
>>> Tapestry squirrels away the Registry object).
>>> 5. You can then get the ApplicationStateManager object from the
>>> Registry, and finally your ASO.
>>>
>>> Hope that helps
>>>
>>> Richard.
>>>
>>> Peter Stavrinides wrote:
>>>> What is the best approach for the following scenario:
>>>>
>>>> I have a listener class that listens for session activity, its
>>>> configured only in my web.xml (not for instance in hivemind)
>>>> I have a state object that I need to inject into the listener
>>>> class, but since I cannot make the listener class abstract how will
>>>> I inject my state object? or what can I do otherwise?
>>>>
>>>> Thanks
>>>> Peter
>>>>
>>>>
>>>> ---------------------------------------------------------------------
>>>> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
>>>> For additional commands, e-mail: users-help@tapestry.apache.org
>>>>
>>>
>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
>>> For additional commands, e-mail: users-help@tapestry.apache.org
>>>
>>
>
>
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> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
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>
--
Peter Stavrinides
Albourne Partners (Cyprus) Ltd
Tel: +357 22 750652
If you are not an intended recipient of this e-mail, please notify the sender, delete it and do not read, act upon, print, disclose, copy, retain or redistribute it. Please visit http://www.albourne.com/email.html for important additional terms relating to this e-mail.
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Re: ASO Injection Question
Posted by Richard Kirby <rb...@capdm.com>.
Hi Peter,
State objects are not the same as HiveMind services. So reg.getService
will return a service you have defined with <service-point /> in a
hivemodule.xml. However these are typically equivalent to singletons and
therefore shared across all sessions. A state object is managed by the
ApplicationStateManager and can be either a global object (in many ways
a HiveMind service is equivalent), or a session object which is per user
web session.
Note that you only need to get the ApplicationStateManager object once
(use lazy initialization), as it will last for the lifetime of the web
application, so something like:
class MySessionListener implements HttpSessionListener {
private ApplicationStateManager asm;
public void sessionCreated(HttpSessionEvent event) {
if (asm == null) {
Registry reg =
(Registry)event.getSession().getServletContext().getAttribute("org.apache.tapestry.Registry:IRM");
asm =
(ApplicationStateManager)reg.getService(ApplicationStateManager.class);
}
Visit visit = (Visit)asm.get("visit");
// do stuff
}
}
Cheers
Richard
Peter Stavrinides wrote:
> Thanks Richard, this is truly a bit of magic, one question though
> regarding the last step:
>
> Is there any reason why I would need to use the
> ApplicationStateManager object, can I rather access a service directly
> using getService() ?
>
> For instance, I get the registry like so:
> Registry reg = (Registry)
> event.getSession().getServletContext().getAttribute("org.apache.tapestry.Registry:IRM");
> //where IRM is the name of the servlet
>
> and then use something like:
> reg.getService(Visit.class);
>
> Thanks again,
> Peter
>
> Richard Kirby wrote:
>> Hi Peter,
>>
>> One way of doing this is to access the HiveMind Registry object that
>> Tapestry creates, from within your listener class, so that you can
>> then access the ApplicationStateManager, and from that access your ASO.
>>
>> However, you have to use a little magic to access the Registry object:
>>
>> 1. From the sessionCreated/sessionDestroyed method you have access to
>> the HttpSessionEvent object.
>> 2. From the HttpSessionEvent object you have access to the
>> HttpSession object.
>> 3. From the HttpSession object you have access to the ServletContext
>> 4. From the ServletContext object you can look up the HiveMind
>> Registry using the getAttribute method with the key
>> "org.apache.tapestry.Registry:SERVLET_NAME" where SERVLET_NAME is the
>> name of the Tapestry application servlet you have specified in your
>> web.xml (this is the magic bit since it requires knowing how Tapestry
>> squirrels away the Registry object).
>> 5. You can then get the ApplicationStateManager object from the
>> Registry, and finally your ASO.
>>
>> Hope that helps
>>
>> Richard.
>>
>> Peter Stavrinides wrote:
>>> What is the best approach for the following scenario:
>>>
>>> I have a listener class that listens for session activity, its
>>> configured only in my web.xml (not for instance in hivemind)
>>> I have a state object that I need to inject into the listener class,
>>> but since I cannot make the listener class abstract how will I
>>> inject my state object? or what can I do otherwise?
>>>
>>> Thanks
>>> Peter
>>>
>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
>>> For additional commands, e-mail: users-help@tapestry.apache.org
>>>
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
>> For additional commands, e-mail: users-help@tapestry.apache.org
>>
>
---------------------------------------------------------------------
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For additional commands, e-mail: users-help@tapestry.apache.org
Re: ASO Injection Question
Posted by Peter Stavrinides <p....@albourne.com>.
Thanks Richard, this is truly a bit of magic, one question though
regarding the last step:
Is there any reason why I would need to use the ApplicationStateManager
object, can I rather access a service directly using getService() ?
For instance, I get the registry like so:
Registry reg = (Registry)
event.getSession().getServletContext().getAttribute("org.apache.tapestry.Registry:IRM");
//where IRM is the name of the servlet
and then use something like:
reg.getService(Visit.class);
Thanks again,
Peter
Richard Kirby wrote:
> Hi Peter,
>
> One way of doing this is to access the HiveMind Registry object that
> Tapestry creates, from within your listener class, so that you can
> then access the ApplicationStateManager, and from that access your ASO.
>
> However, you have to use a little magic to access the Registry object:
>
> 1. From the sessionCreated/sessionDestroyed method you have access to
> the HttpSessionEvent object.
> 2. From the HttpSessionEvent object you have access to the HttpSession
> object.
> 3. From the HttpSession object you have access to the ServletContext
> 4. From the ServletContext object you can look up the HiveMind
> Registry using the getAttribute method with the key
> "org.apache.tapestry.Registry:SERVLET_NAME" where SERVLET_NAME is the
> name of the Tapestry application servlet you have specified in your
> web.xml (this is the magic bit since it requires knowing how Tapestry
> squirrels away the Registry object).
> 5. You can then get the ApplicationStateManager object from the
> Registry, and finally your ASO.
>
> Hope that helps
>
> Richard.
>
> Peter Stavrinides wrote:
>> What is the best approach for the following scenario:
>>
>> I have a listener class that listens for session activity, its
>> configured only in my web.xml (not for instance in hivemind)
>> I have a state object that I need to inject into the listener class,
>> but since I cannot make the listener class abstract how will I inject
>> my state object? or what can I do otherwise?
>>
>> Thanks
>> Peter
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
>> For additional commands, e-mail: users-help@tapestry.apache.org
>>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
>
--
Peter Stavrinides
Albourne Partners (Cyprus) Ltd
Tel: +357 22 750652
If you are not an intended recipient of this e-mail, please notify the sender, delete it and do not read, act upon, print, disclose, copy, retain or redistribute it. Please visit http://www.albourne.com/email.html for important additional terms relating to this e-mail.
---------------------------------------------------------------------
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Re: ASO Injection Question
Posted by Richard Kirby <rb...@capdm.com>.
Hi Peter,
One way of doing this is to access the HiveMind Registry object that
Tapestry creates, from within your listener class, so that you can then
access the ApplicationStateManager, and from that access your ASO.
However, you have to use a little magic to access the Registry object:
1. From the sessionCreated/sessionDestroyed method you have access to
the HttpSessionEvent object.
2. From the HttpSessionEvent object you have access to the HttpSession
object.
3. From the HttpSession object you have access to the ServletContext
4. From the ServletContext object you can look up the HiveMind Registry
using the getAttribute method with the key
"org.apache.tapestry.Registry:SERVLET_NAME" where SERVLET_NAME is the
name of the Tapestry application servlet you have specified in your
web.xml (this is the magic bit since it requires knowing how Tapestry
squirrels away the Registry object).
5. You can then get the ApplicationStateManager object from the
Registry, and finally your ASO.
Hope that helps
Richard.
Peter Stavrinides wrote:
> What is the best approach for the following scenario:
>
> I have a listener class that listens for session activity, its
> configured only in my web.xml (not for instance in hivemind)
> I have a state object that I need to inject into the listener class,
> but since I cannot make the listener class abstract how will I inject
> my state object? or what can I do otherwise?
>
> Thanks
> Peter
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
>
---------------------------------------------------------------------
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