Running EMF-IncQuery as an RCP application


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The contents of this page have been superseded by the following page on the Eclipse Wiki:


EMF-IncQuery can be used without any graphical user interface (headless). In this example, we take an existing IncQuery project and based on it, we create a (headless) Eclipse Application that can be executed from a console (command prompt) to print the matches for an arbitrary input model file.

First, the IncQuery project headless.incquery can be downloaded from: The project contains a single pattern that matches on Ecore models:

Next, observe the application project org.eclipse.viatra2.emf.incquery.application (available at the same place). The project includes two class files:

  • IncQueryApplication: by implementing the IApplication interface, it provides a single entrypoint that is also capable of handling command line parameters. It checks that the input model is provided using the -m <modelPath> switch, the query name provided using the -p <patternFQN> switch and then invokes the pattern matcher.
    • To execute the example (on Windows), call as follows (assuming the current folder contains eclipse.exe and the model can be found at c:/test/input.ecore): eclipse.exe -m c:/test/input.ecore - p somePackage.somePattern
  • IncQueryHeadless: with a single method execute(String modelPath) that will first try to load the model found at modelPath into an EMF Resource, and if that was successful, it creates a matcher (for the EClassNames pattern) and retrieves the matches as a collection. The actual code also includes some additional fragments to illustrate performance measurements (timed execution for the EMF loading, IncQuery initialization and matchset retrieval phases). Finally, the matches are printed using IPatternMatch.prettyPrint().

Next, the application itself is registered through the org.eclipse.core.runtime.applications extension point. The plugin.xml file defines the extension.

Finally, a product configuration is required in order to run this application as an Eclipse product, and to be able to export it into a standalone application that can be called from the console. Apart from adding the required plugins to the configuration, an org.eclipse.core.runtime.products extension is required as well (also found in plugin.xml):

If only the minimum required plugins are exported, the resulting eclipse folder is around 30 MB, which is quite small considering that an Eclipse Modeling distribution is around 300 MB.

Note that you may have to remove the platform-specific features that are for different platforms (e.g. Linux and MacOS X when using Windows).