## Frequently Asked Questions about AJDT

Last updated on 30th June 2004.

1 Overview
  1. What is AJDT?
  2. Who develops AJDT?
  3. Where can I get the latest version?
  4. How does AJDT relate to the AspectJ project?
2 Community
  1. Are there any newsgroups for AJDT users?
  2. What do I do if I think I've found a bug in AJDT?
  3. How can I request a new feature in AJDT?
  4. Is there an AJDT mailing list?
3 Using AJDT
  1. Why aren't AspectJ keywords highlighted in the editor?
  2. Why are keywords like "aspect" underlined as problems?
  3. Why doesn't the outline view update as I type in the editor?
  4. How can I debug AspectJ programs in Eclipse?
  5. How does the Visualiser work?
  6. What happened to the JoinPoint probe?
4 Contributing
  1. How can I contribute to the AJDT project?
  2. How can I package my sample code for contribution to the examples plugin?
  3. Where will I find the source for AJDT?
  4. How do I setup an AJDT development environment in Eclipse?
5 Plans
  1. What new AJDT features are being worked on at the moment?

### 1 Overview

1. What is AJDT?

The AspectJ Development Tools project (AJDT) is a set of plugins for Eclipse that provide support for aspect-oriented software development using AspectJ within the Eclipse IDE.

2. Who develops AJDT?

AJDT is an open-source project hosted on eclipse.org, current contributors are listed on the website. Anyone can get involved, see "How can I contribute?"

3. Where can I get the latest version?

Details about how to get hold of AJDT are available from the download page.

4. How does AJDT relate to the AspectJ project?

AJDT provides Eclipse IDE integration for AspectJ, and includes the AJDE (AspectJ Development Environment) libraries from the AspectJ project as part of its packaging. Development of the AspectJ compiler and AJDE takes place under the AspectJ project.

### 2 Community

1. Are there any newsgroups for AJDT users?

AJDT is supported through the eclipse.technology.ajdt newsgroup. A web interface is also available.

2. What do I do if I think I've found a bug in AJDT?

First check the bug database to see if you've hit a known problem. There's also a view built into AJDT (Window->Show View->Other...->AspectJ->AJDT Event Trace) that displays a lot of diagnostic information about the execution of the plugin (for example, it will show you the exact classpaths being used for compilation). If it appears to be a genuinely new bug, please submit a bug report on AJDT using bugzilla following the bug reporting guidelines.

3. How can I request a new feature in AJDT?

Informal requests can be posted to the newsgroup or mailing list. Formal requests can be made by raising an AJDT enhancement request on Bugzilla.

4. Is there an AJDT mailing list?

AJDT has a developers mailing list, ajdt-dev@dev.eclipse.org, with archives and subscription information available online. Questions regarding the use of AspectJ the language are best directed to the AspectJ users mailing list.

### 3 Using AJDT

1. Why aren't AspectJ keywords highlighted in the editor?

The most common cause of this problem is opening Java files (files with the .java extension) using the JDT's Java Editor. AJDT provides an extension to the Java Editor, the AspectJ Editor, that recognizes AspectJ language structure and provides an outline view that displays crosscutting structure information. To configure Eclipse so that Java files are opened with the AspectJ editor, select "preferences" from the Window menu. Expand the workbench preferences and click on "File Associations." Select file type "*.java," then select the AspectJ Editor and click the "Default" button.

2. Why are keywords like "aspect" underlined as problems (red squiggle underline)?

AJDT doesn't yet provide an eager parser for AspectJ. The early problem indication support is therefore expecting to see a regular Java program, and so treats AspectJ keywords as errors. The squiggles can be turned off by opening preferences from the Window menu: Expand the Java preferences and click on "Editor." In the "Problem Indication" tab, uncheck the option "Show problems before compiling."

3. Why doesn't the outline view update as I type in the editor?

AJDT doesn't yet provide an eager parser for AspectJ, so the understanding of the editor buffer contents needed to update the outline view is only after a compilation. The process of compiling creates a structure model (including the crosscutting information) that the outline view then renders.

4. How can I debug AspectJ programs in Eclipse?

Working with with AspectJ programs in the debugger has the following limitations:

- You can step into and through most aspect code but around advice is still problematic - use "step into" instead of "step over" on an advised line of source in order to step into the aspect code.
- If you use "step over" to step past a line of code, this will also step over any advice applied to that line in one step.

NB. Since 1.1.11 breakpoints can be set in aspects as well as in classes.

5. How does the Visualiser work?

The Visualiser consists of two views, the Visualiser and the Visualiser Menu, both of which need to be open: Select "Window" , "Show View" , "Other... Visualiser" from the taskbar, then select "Visualiser" and "Visualiser Menu " and click OK. Alternatively, open the Aspect Visualization perspective by clicking "Window", "Open Perspective", "Other... Aspect Visualization".

The Visualiser has a provider architecture - other plugins define content providers that plug in to the Visualiser through extension points. Only one provider can be active at a time. The active provider determines the bars and stripes that are shown. You can tell which provider is active from the Visualiser title bar. If the AspectJ provider is not active by default, click "Window", "Preferences", then select "Visualiser", select the AspectJ Provider, then click OK.

To visualize an AspectJ project, click on the AspectJ Project in the Package Explorer or the Projects view. If the project has been built the aspects defined in that project should appear in the Menu. The Visualiser shows all the classes in your project with bar length proportional to number of lines of code. Dark bars represent classes not affected by an aspect. Coloured lines on the white bars represent lines of code affected by the Aspect in the Menu with the corresponding colour. It is also possible to click on individual classes or packages in the package explorer to see their individual representations.

The Visualiser starts in class view by default. Click on the package button to choose package view. Here each bar represents a package in your project and length is proportional to total number of lines. Package view was designed as an overview, particularly for large projects. Click on the class button to return to class view.

In either package or class view, clicking on the limit button restricts the view to affected bars only. Clicking again leaves limit mode.

To open the source file of a represented class, double click on the corresponding bar. To open a source file at a line affected by an aspect, double click on the corresponding coloured stripe.

If you would like to find out more the Visualiser has its own Eclipse help pages.

6. What happened to the JoinPoint probe?

The JoinPoint probe was an experimental function that made a brief appearance in AJDT 0.5.2 and 0.6.0beta. We have temporarily removed it from AJDT whilst we work out the correct user-interaction model and port the Swing UI to SWT.

### 4 Contributing

1. How can I contribute to the AJDT project?

Your contributions to the AJDT project are strongly welcomed! You can create a patch that fixes a bug or provides an enhancement and submit it to the AJDT developers either as an attachment to a bug in Bugzilla, or as an attachment to a post to the newsgroup or developer mailing list. You can also contribute sample code showing interesting uses of AspectJ, by adding entries to the example plugin. All contributions must be made available under the terms of the Eclipse website see the Eclipse contribution and participation FAQ. Sorry, but for legal reasons we are unable to accept patches emailed directly to developers, and will normally ask you to resubmit these either via Bugzilla or the mailing list.

AJDT development is run as a meritocracy, developers who have a track record of submitting good patches can become committers on the project.

2. How can I package my sample code for contribution to the examples plugin?

The org.eclipse.ajdt.examples plugin contains various sample projects which are made available under the Examples category of the New wizard, from where they can be imported into your workspace as AspectJ projects. It is easy to add new samples to this plugin, as follows:

- Create a jar file containing your source code, and at least one build configuration file. Place this in the archive folder of the examples plugin.
- Add an entry to the plugin.xml file for your sample project, by copying one of the existing entries.
- Change the src attribute of the import element to refer to your jar file, and change the title, description, pagetitle, and pagedescription property names as appropriate, and add corresponding entries to the plugin.properties file.
- Change the build attribute to refer to your default build configuration file. Your project may contain more configurations but the one specified here will be the one used to initially build the project.
- Optionally, you can specify an open attribute to the projectsetup element, which refers to a file, such as a README file, which is opened after the project has been imported to the workspace.

3. Where will I find the source for AJDT?

AJDT source is held in the Eclipse CVS repository under /home/technology, see the root of the AJDT source tree online. The latest source can be found in subdirectories of org.eclipse.ajdt as follows:

      org.eclipse.ajdt
    	|
    	|--> AJDT_30M9_src
    		|--> org.eclipse.ajdt
    		|--> org.eclipse.ajdt.examples
    		|--> org.aspectj.ajde
    		|--> org.eclipse.aspectj
    		|--> org.eclipse.aspectj.feature
    		|--> org.eclipse.contribution.visualiser
    		|--> org.eclipse.contribution.visualiser.tests
    		|--> UpdateSite

4. How do I setup an AJDT development environment in Eclipse?

Start with a clean workspace under Eclipse 3.0:

- Prepare your workspace for self-hosting: from the File menu select "Import...", choose "External plugins and fragments" and click "Next". Click "Next" again, the press then "Select All" button and click "Finish." If you are not in it already, switch to the Java Perspective. To reduce the clutter in the Package Explorer, click the downward pointing arrow icon on the Package Explorer toolbar, then choose "Filters..." Check "Hide binary plug-in projects" and press OK.
- Create a CVS repository connection to dev.eclipse.org: connection type pserver, your username and password (or anonymous), repository path /home/technology, for example

      :pserver:anonymous@dev.eclipse.org:/home/technology

  (Detailed instructions...)
  - From the Window menu, select "Open Perspective..." , then "CVS Repository Exploring"
  - From the context menu in the CVS Repositories view, select New... Repository Location
  - Host = dev.eclipse.org, Repository path = /home/technology
  - Your userid and password, or "anonymous"
  - Connection type = pserver
  - Click "Finish"

- Use the CVS Repositories view to navigate to org.eclipse.ajdt/AJDT_30M9_src. Select all the folders in that directory apart from "Update Site". From the context (right mouse button) menu select "Check out". Eclipse will build the projects as you import them, so you're ready to run the plugins inside Eclipse straight away:
  - Switch back to the Java Perspective if you're not already in it...
  - From the run menu select "Run..."
  - Select "Run-time workbench" and click new
  - Give your launch configuration a name, and click "Run"
  - Subsequent runs can simpy use the launch configuration you just created
  Now you're ready to start enhancing the plugins by adding to or extending the code in your projects - just use run (or debug) to test your changes. When you have a cool patch or bug fix to submit to the project, go the the "Team" item in the project context menu and select "Create Patch..."

  Each of the projects you just created also contains an Ant build file, "build.xml." The default target builds a packaged version of the project in question. Use the build.xml file in the "update" project to invoke a master build that builds an entire update site structure in its "dist" directory.

  - Copy the contents of the dist directory to a clean directory, outside of your workspace. For example, "ajupdate."
  - From the help menu of the Eclipse in which you wish to install the AspectJ feature, choose "Software Updates..." and then "Update Manager."
  - Expand the "My Computer" branch and navigate to the "ajupdate" directory, and then "AspectJ."
  - Select "Eclipse AspectJ Development Tools" and then click on the "Install" button.

### 5 Plans

1. What new AJDT features are being worked on at the moment?

See the task list on our project home page.