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Posted to users@tapestry.apache.org by satb <sa...@yahoo.com> on 2010/03/31 20:37:36 UTC
How to get the Component inside advice?
I am trying to get the component inside an advice and if the page invoked is
extends "SecurePage", then I have to check the security credentials on that
request. A typical cross-cutting concern which is best served by an advice.
But its not working. Anything I am doing wrong here? Could this below
problem be a classloader problem?
@Match("SecureInterface")
public static void adviceSecureRequest(MethodAdviceReceiver receiver, final
Request request,
final ComponentClassResolver
componentClassResolver,
final RequestPageCache
cache, final AuthService authService){
MethodAdvice advice = new MethodAdvice(){
public void advise(Invocation invocation){
//SOME PLUMBING CODE TO GET TO THE COMPONENT.
//DON'T KNOW IF THERE IS AN EASIER WAY.
String path = request.getPath();
int actionEvent = path.lastIndexOf('.');
if (actionEvent != -1)
path = path.substring(0, actionEvent);
int nextslashx = path.length();
String pageName;
while (true) {
pageName = path.substring(1, nextslashx);
if (!pageName.endsWith("/") &&
componentClassResolver.isPageName(pageName))
break;
nextslashx = path.lastIndexOf('/', nextslashx - 1);
if (nextslashx <= 1)
break;
}
if (componentClassResolver.isPageName(pageName)){
Page page = cache.get(pageName);
//NOW WE HAVE A HANDLE ON THE COMPONENT
Component component = page.getRootComponent();
//THE BELOW IF CONDITION ALWAYS FAILS.
//AS AN EXAMPLE, THIS "component" could be a
"PayPage" page which extends "SecurePage".
//SO component HERE SHOULD ACTUALLY BE "PayPage" AND
THEREFORE A "SecurePage". BUT, THE CONDITION ISN'T SATISFIED
//I DOUBLE CHECKED THE HASHCODE of "PayPage" in
BeginRender of PayPage and that of "component" over here AND BOTH ARE
IDENTICAL.
//SO I AM CONFUSED WHY THE BELOW CONDITION WOULD FAIL.
//IS THIS A CLASSLOADER PROBLEM???? IF THE HASHCODE IS
THE SAME
//THEN THEY ARE THE SAME OBJECTS, SO WHY IS THE BELOW
CONDITION FAILING?
if (component instanceof SecurePage)
authService.checkSecurity(invocation.getParameter(0)); // I NEED TO CALL
THIS TO CHECK THE CREDENTIALS IF THE PAGE IS A "SecurePage"
}
invocation.proceed();
} // end advice method of inner class
}; // end inner class
receiver.adviseAllMethods(advice);
}
--
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Re: How to get the Component inside advice?
Posted by Peter Stavrinides <P....@albourne.com>.
> I hope to have a simple authentication
> framework, possibly as a Tapestry extension, at some point in the next
> couple of months.
Great news Howard, I will look forward to that!!
----- Original Message -----
From: "Howard Lewis Ship" <hl...@gmail.com>
To: "Tapestry users" <us...@tapestry.apache.org>
Sent: Wednesday, 31 March, 2010 22:59:19 GMT +02:00 Athens, Beirut, Bucharest, Istanbul
Subject: Re: How to get the Component inside advice?
Chances are your instanceof is failing because you put the SecurePage
interface into the pages or components package; move it up a level, to
a non-controlled package, so that the services layer and the component
layer can agree. Anything inside the pages or components packages (or
mixins or base) will be loaded by a different class loader, and this
causes these apparently anomalous ClassCastExceptions.
But Thiago is right, Tapestry has a proper place for this kind of
thing, if you check my blog, you'll see an article where I head down
the same path as you (I've recently done this kind of thing for a
couple of different clients). I hope to have a simple authentication
framework, possibly as a Tapestry extension, at some point in the next
couple of months.
On Wed, Mar 31, 2010 at 12:31 PM, satb <sa...@yahoo.com> wrote:
>
>> Advice is for services, not pages and components.
>
> Thanks for the response.
>
> Yes. That is true. I want to do one other thing on the methods of the
> service if the request is originating from a "SecurePage" -- which is to
> check the credentials. Isn't advice the right thing for it? Thats what the
> above advice is trying to do except the "instaceof" check is always
> returning false.
>
> I guess what is causing some concern to me is -- why would "component
> instanceof SecurePage" return false?
> --
> View this message in context: http://old.nabble.com/How-to-get-the-Component-inside-advice--tp28100055p28100745.html
> Sent from the Tapestry - User mailing list archive at Nabble.com.
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
>
>
--
Howard M. Lewis Ship
Creator of Apache Tapestry
The source for Tapestry training, mentoring and support. Contact me to
learn how I can get you up and productive in Tapestry fast!
(971) 678-5210
http://howardlewisship.com
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Re: How to get the Component inside advice?
Posted by Howard Lewis Ship <hl...@gmail.com>.
Chances are your instanceof is failing because you put the SecurePage
interface into the pages or components package; move it up a level, to
a non-controlled package, so that the services layer and the component
layer can agree. Anything inside the pages or components packages (or
mixins or base) will be loaded by a different class loader, and this
causes these apparently anomalous ClassCastExceptions.
But Thiago is right, Tapestry has a proper place for this kind of
thing, if you check my blog, you'll see an article where I head down
the same path as you (I've recently done this kind of thing for a
couple of different clients). I hope to have a simple authentication
framework, possibly as a Tapestry extension, at some point in the next
couple of months.
On Wed, Mar 31, 2010 at 12:31 PM, satb <sa...@yahoo.com> wrote:
>
>> Advice is for services, not pages and components.
>
> Thanks for the response.
>
> Yes. That is true. I want to do one other thing on the methods of the
> service if the request is originating from a "SecurePage" -- which is to
> check the credentials. Isn't advice the right thing for it? Thats what the
> above advice is trying to do except the "instaceof" check is always
> returning false.
>
> I guess what is causing some concern to me is -- why would "component
> instanceof SecurePage" return false?
> --
> View this message in context: http://old.nabble.com/How-to-get-the-Component-inside-advice--tp28100055p28100745.html
> Sent from the Tapestry - User mailing list archive at Nabble.com.
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
>
>
--
Howard M. Lewis Ship
Creator of Apache Tapestry
The source for Tapestry training, mentoring and support. Contact me to
learn how I can get you up and productive in Tapestry fast!
(971) 678-5210
http://howardlewisship.com
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Re: How to get the Component inside advice?
Posted by "Thiago H. de Paula Figueiredo" <th...@gmail.com>.
On Wed, 31 Mar 2010 16:31:17 -0300, satb <sa...@yahoo.com> wrote:
>> Advice is for services, not pages and components.
>
> Thanks for the response.
>
> Yes. That is true. I want to do one other thing on the methods of the
> service if the request is originating from a "SecurePage" -- which is to
> check the credentials. Isn't advice the right thing for it?
Again, advice is for services, not pages and components. If you want to
advise pages and components, you'll need to implement a
ComponentClassTransformWorker.
To check the origin of a request, you'll need to use the Referrer HTTP
header or put something in the URL.
> Thats what the
> above advice is trying to do except the "instaceof" check is always
> returning false.
Please post your code or we cannot help you.
--
Thiago H. de Paula Figueiredo
Independent Java, Apache Tapestry 5 and Hibernate consultant, developer,
and instructor
Owner, software architect and developer, Ars Machina Tecnologia da
Informação Ltda.
http://www.arsmachina.com.br
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Re: How to get the Component inside advice?
Posted by satb <sa...@yahoo.com>.
> Advice is for services, not pages and components.
Thanks for the response.
Yes. That is true. I want to do one other thing on the methods of the
service if the request is originating from a "SecurePage" -- which is to
check the credentials. Isn't advice the right thing for it? Thats what the
above advice is trying to do except the "instaceof" check is always
returning false.
I guess what is causing some concern to me is -- why would "component
instanceof SecurePage" return false?
--
View this message in context: http://old.nabble.com/How-to-get-the-Component-inside-advice--tp28100055p28100745.html
Sent from the Tapestry - User mailing list archive at Nabble.com.
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Re: How to get the Component inside advice?
Posted by "Thiago H. de Paula Figueiredo" <th...@gmail.com>.
On Wed, 31 Mar 2010 15:37:36 -0300, satb <sa...@yahoo.com> wrote:
> I am trying to get the component inside an advice and if the page
> invoked isextends "SecurePage", then I have to check the security
> credentials on that request.
A way better way of doing it is to implement a ComponentEventRequestFilter
and contribute it to the service ComponentEventRequestHandler. Take a look
at the graph in the end of
http://tapestry.formos.com/nightly/tapestry5/guide/request.html to have a
better look at how Tapestry processes requests.
> A typical cross-cutting concern which is best served by an advice.
Advice is for services, not pages and components.
By the way, looking at your advice, there's the ComponentEventLinkEncoder
service that provides methods like PageRenderRequestParameters
decodePageRenderRequest(Request request) to deal with extracting the page
name from a request.
--
Thiago H. de Paula Figueiredo
Independent Java, Apache Tapestry 5 and Hibernate consultant, developer,
and instructor
Owner, software architect and developer, Ars Machina Tecnologia da
Informação Ltda.
http://www.arsmachina.com.br
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