Revision as of 09:44, March 20, 2009

Setting up Eclipse for plug-in development

This page is intended for people who want to develop their own plug-in (e.g., tab widget, slot widget, project plug-in, etc.) and who use Eclipse as their Java development environment. This is a step-by-step guide that shows the setup of the Eclipse environment using screen shots. We will use as an example the scenario in which a developer wants to create a tab widget that displays "Hello World!". These steps can be used for developing any plug-in type.

Prerequisites

Before we start, make sure that you have the latest version of Protege 3.x and Eclipse installed.

1. Download and install Eclipse from here.
2. Download and install latest version of Protege 3.x from here. Let's say you have installed Protege in:

Setting up Eclipse

Step 1. Create a new Java Project

Start Eclipse. Go to File Menu -> New -> Project -> Select Java Project. Click Next. In the next panel choose a project name, say "HelloWorldTab". The screen should look like below:

Click Finish. Congratulations! You have created an empty Java project. Your screen should look like:

Step 2. Configure the project build path

This step assumes that you have Protege 3.x installed on your computer. This example assumes that Protege was installed in /work/protege/Protege_3.4 (On Windows machines, the default installation directory would be something like C:\Program Files\Protege_3.4)

Select the project name, HelloWorldTab', right click, select Build Path -> Configure Build Path.... Switch to the Libraries tab. You should see an something like this:

Click on Add External JARs... and go to the Protege installation directory. Select from there the:

• protege.jar
• looks-2.1.3.jar (version may vary)

Click OK.

If your plug-in is for OWL, you will need to include also all the jars in the protege-owl plug-in folder. Repeat the same operation: Click Add External Jars, go to the Protege installation directory/plugins/edu.stanford.smi.protegex.owl and select all the jar files in that directory.

Note If your plug-in depends on other plug-ins (e.g., on the Change Management plug-in), then you need to add to the build path also all the jars in that plug-in folder.

After adding the Protege jars (and the protege-owl jars), the Library tab should look like:

Click OK.

Step 3. Create the Java plug-in class

OK, so now Eclipse is set up, all we need is to create a new tab widget. We have documentation about implementing different plug-in types on our Developer's webpage.

This guide will create a tab widget that displays "Hello World". To create a Tab Widget, you need to extend the class edu.stanford.smi.protege.widget.AbstractTabWidget from the protege.jar and implement the method initialize() that is called when the tab is created.

Right-click on src, select New -> Class. In the new class panel:

• Write in the Name field: HelloWorldTab
• Write in the Superclass field: AbstractTabWidget (auto-completion also works, press Ctrl+Space)
• Write in the Package field: mytab

This is what you should see:

Click Finish. The new class should show up under the src folder. An empty implementation of the initialize method was already created by Eclipse. You should see this:

You can replace the code of the class with the one from below (just prints "Hello World!"):

package mytab;

import javax.swing.JLabel;

import edu.stanford.smi.protege.widget.AbstractTabWidget;

public class HelloWorldTab extends AbstractTabWidget {

	public void initialize() {		
		add(new JLabel("Hello World!"));
	}

	public static void main(String[] args) {
		edu.stanford.smi.protege.Application.main(args);
	}
	
}

Our HelloWorldTab plug-in will display "Hello World!" in a tab.

Step 4. Create the manifest file

To make Protege recognize the new tab widget, you will need to create a manifest file. We have instructions about creating the manifest file here.

Right-click on src -> New -> Folder. In the panel, select the src node, and folder name: META-INF (capital letters!). This is what you should see:

After you click on Finish, the new folder META-INF is created under src.

Right-click on the META-INF folder, New -> File. In the panel, select META-INF, and for the file name write: MANIFEST.MF (capital letters!). This is how it should look like:

Click Finish.

Copy and paste the text from below in the content of the just created MANIFEST.MF:

Manifest-Version: 1.0

Name: mytab.HelloWorldTab.class
Tab-Widget: True

The empty row at the end of the file is very important!

Save the MANIFEST.MF file (by clicking Ctrl+S) and this is what you should see:

Step 5. Run the plug-in

So far, we have all we need to start the new plug-in. All we need now is to set up a run configuration for executing the plug-in.

Go to Run Menu -> Run Configurations.... Create a new Java Application launcher, by selecting the Java Application in the tree and click on the create icon at the top of the panel. Fill in the following values:

• Name: HelloWorldTab
• Project: Select HelloWorlTab
• Main class: mytab.HelloWorldTab

Eclipse will fill in automatically for you some of these values. This is what you should see:

Then, switch to the Arguments tab, and for Working Directory select Other, then click on File System.. and select the path to your Protege installation directory . This is a very important step of the configuration.

In our example, Protege is installed in /work/protege/Protege_3.4 and this is the value that we select. See screen shot from below:

Click Run.

TO BE CONTINUED