[aspectj-users] Re: Weaving into a Java Project

[Holger Gulrot <holger.gulrot@xxxxxxxxx>]

Hi,

Thank you for your reply! I was not aware that the woven class file will not be situated in WeavingTarget. So, I first tried the simple solution that you proposed and found out that it is only working when setting a required plug-in dependency to WeavingSource in WeavingTarget's manifest file. So, it is now working but not really what I want to do. Thus, I tried to use equinox aspects. LTW was what I initially had in mind for my use case but I thought that compile-time weaving would be easier to realise.

For the equinox aspects example I used the same setup. WeavingTarget is still the Sample XML Editor plug-in. WeavingSource is still a plug-in that contains only the mentioned aspect and is an aspectj project. According to the equinox aspects quick-start guide WeavingSource's manifest file looks like the following:

     Manifest-Version: 1.0
     Bundle-ManifestVersion: 2
     Bundle-Name: WeavingSource
     Bundle-SymbolicName: WeavingSource
     Bundle-Version: 1.0.0.qualifier
     Require-Bundle: org.aspectj.runtime;visibility:=reexport
     Export-Package: weavingsource
     Bundle-ActivationPolicy: lazy
     Bundle-RequiredExecutionEnvironment: J2SE-1.5
     Import-Package: org.osgi.framework;version="1.5.0"
     Eclipse-SupplementBundle: weavingtarget

The aop.xml file in the manifest folder just contains:

     <?xml version="1.0" encoding="UTF-8"?>
     <aspectj>
         <aspects>
             <aspect name="weavingsource.ActivatorAspect" />
         </aspects>
     </aspectj>

And at last the run-configuration parses, among others, the following arguments to the VM:

     -Dorg.aspectj.osgi.verbose=true -Dosgi.framework.extensions=org.eclipse.equinox.weaving.hook


When starting the run-time, the information 

     [org.eclipse.equinox.weaving.hook] info adding AspectJ hooks ...

is displayed. But, when opening the Sample XML Editor no aspect message is displayed. What is the reason for this behavior? Using LTW it cannot be that the woven class is in the wrong plug-in. Is it that the aspect class file is not found?
 
Best,
Holger

> Over the context menu's properties entry I set the Inpath of "WeavingSource"
> to the project "WeavingTarget" and enabled the output of weaving information
> to the problems view.

This configuration means that when building WeavingSource it will
consume the output class files from WeavingTarget, apply the aspect,
and then write the woven class files *to the output folder for
WeavingSource*.  WeavingTarget is completely untouched and the class
files within it remain unwoven.  This means you will only be executing
the woven classes if you 'run'/'load' those in the WeavingSource as
replacements for those in WeavingTarget.

The simplest configuration is Convert WeavingTarget to an AspectJ
project then put WeavingSource on its aspectpath.  I realise you don't
want to change WeavingTarget, but this would be the simplest way.  Or
you could use equinox aspects weaving as you are in a plugin
environment anyway, that will load time weaving your aspect, but
weaving is then a loadtime activity rather than a compile time
activity.

Andy

2010/1/11 Holger Gulrot <holger.gulrot@xxxxxxxxx>:
> Dear all,
>
> I am new to this list and new to Aspectj, and I would like to ask my first,
> perhaps a freshman, question.
>
> Question:
> Why is advice of an aspect in one eclipse plug-in not invoked when running
> another eclipse plug-in that contains a class with the corresponding join
> point despite ajdt telling me that the join point is advised?
>
> Explanation:
> I have two eclipse plug-in projects. As a minimal example, I created a
> plug-in "WeavingTarget" that contains the "Sample XML Editor" which you can
> choose when creating a new plug-in project. As a second plug-in, named
> "WeavingSource", I generated an empty plug-in project (without an activator)
> converted it into an Aspectj project (using the context menu entry) and
> added the following aspect to it:
>
>
>     package weavingsource;
>
>     public aspect ActivatorAspect {
>
>         pointcut start() : execution(public void *.start(..));
>
>         after() : start() {
>             System.out.println("plugin was started");
>         }
>     }
>
> Over the context menu's properties entry I set the Inpath of "WeavingSource"
> to the project "WeavingTarget" and enabled the output of weaving information
> to the problems view. Where the folowing information gets displayed:
>
>     Join point 'method-execution(void
> weavingtarget.Activator.start(org.osgi.framework.BundleContext))' in Type
> 'weavingtarget.Activator' (Activator.java:28)     advised by after advice
> from 'weavingsource.ActivatorAspect' (ActivatorAspect.aj:7)    WeavingSource
>
> Thus I assume that my advice was correctly applied to the specified join
> point.
>
> After starting eclipse's runtime instance (via run as eclipse application)
> and after opening an xml file with the Sample XML Editor, the Activator's
> start method was called and the console should display the message specified
> in the aspect's advice.
> But this does not happen. Why? Do I need to set something else/more then the
> Inpath of "WeavingSource"? Even setting a plug-in dependency in the manifest
> file from "WeavingSource" to "WeavingTarget" does not produce another
> result...
> For testing purposes I put the aspect next to the Activator in the
> "WeavingTarget" plug-in and this results in displaying the aspect's advice
> message when opening the Sample XML Editor. I do not want to make use of
> this workaround since I want to leave the "WeavingTarget" plug-in
> unmodified.
>
> Setup:
> I am using eclipse galileo (3.5.1) with ajdt (2.0.1) and aspectj (1.6.6).
>
>
> I would appreciate if you could help me out.
>
> Best,
> Holger
>