Plugin Development

##Structure

The plugins are developed using E4 Eclipse RCP platform. The source code is contained in three or four packages based on the functionalities within the src directory. An example of the structure is given below.

• edu.usc.cssl.nlputils.plugins.weightedCount.handlers - contains menu item handler
• edu.usc.cssl.nlputils.plugins.weightedCount.parts - contains the GUI code
• edu.usc.cssl.nlputils.plugins.weightedCount.process - contains the core algorithm

The contributions of the plugin to the main application should be configured in the e4xmi file.

##Menu Contribution

If your plugin has to create a new menu in the main menu bar, a child menu should be created under menu:org.eclipse.ui.main.menu. For example, edu.usc.cssl.nlputils.application.menu.wordcount

If your plugin has to create a handled menu item under one of the available menus, add a handled menu item in the e4xmi file and contribute it to one of the menus. A list of the current menus are given below.

Crawl - edu.usc.cssl.nlputils.application.menu.crawlers

Preprocess - edu.usc.cssl.nlputils.application.menu.preprocessors

Word Count - edu.usc.cssl.nlputils.application.menu.wordcount

Classify - edu.usc.cssl.nlputils.application.menu.classifiers

Topic Model - edu.usc.cssl.nlputils.application.menu.topic

Clustering - edu.usc.cssl.nlputils.application.menu.clustering

Plugins - edu.usc.cssl.nlputils.application.menu.plugins

Part Contribution

The GUI of your plugin should be implemented as a part and it should be added to the part stack of the main application having the ID org.eclipse.e4.ide.partstack . The visibility of the part should not be set and it should be made visible using the handler of the menu item.

Printing output on the console

Import the package edu.usc.cssl.nlputils.utilities and call the function Log.append(context, message) to print the message on the console. The context object can be obtained through dependency injection.

Global Preprocessing Options

For accessing the global preprocessing settings, import edu.usc.cssl.nlputils.plugins.preprocessorService.services.PreprocessorService. Options can be set with setOptions(shell) function and preprocessing can be performed using doPreprocessing(outputDirectory) function.

Adding your plugin to the application

There are two ways to add your plugin to the main application. You can add it to the main application's dependencies. This is a very easy way to include the plugin in the application while testing. The drawback is that other users will not be able to use your plugin. For sharing the plugin with the community, you have to export the plugin and install it in the application using the Plugins > Add Plugin menu option.