Creating transformations

You can create transformations that transform models into models, transform models into text or code, or create transformations that transform code into models in a different way from the language-specific transformations in the product. You should create a transformation if you cannot generate the required transformation output by extending an existing transformation. You can create a transformation in any Eclipse plug-in project.

About this task

When you create a transformation by using the New Transformation Authoring Project wizard, the following artifacts are generated in the plug-in automatically:

An instance of the transformation provider extension point
A transformation provider implementation
A transformation implementation
Optional: An implementation file for each rule that you specify

You can also add these elements manually to any existing Eclipse plug-in.

For more information about these elements, see the following developer guides:

Rational® Transformation Developer Guide
Rational Transformation Authoring Developer Guide

Note: Some information, such as links to Eclipse documentation or to developer guides, is available only from the help topics that are installed with the product.

Creating transformation projects
To create a transformation, you must create an Eclipse plug-in that contains an instance of the transformation provider extension point and a transformation provider.
Creating instances of the transformation provider extension point in plug-ins
You can add instances of the extension point named com.ibm.xtools.transform.core.transformationProviders to existing Eclipse plug-ins. This extension point facilitates the creation and configuration of transformation providers for the transformation service. You must create an instance of this extension point before adding transformation providers to the plug-in.
Creating instances of transformation extensions extension points in plug-ins
You can add instances of the extension point named com.ibm.xtools.transform.core.transformationExtensions to existing Eclipse plug-ins. This extension point facilitates the configuration of extensions to transformations that are registered with the transformation service.
Creating transformation providers in plug-ins
You can add transformation providers to existing Eclipse plug-ins that declare instances of the extension point named com.ibm.xtools.transform.core.transformationProviders. A transformation provider is the mechanism that defines transformations, which appear as transformation elements in the plug-in manifest file.
Creating transformations in plug-ins
You can add transformations to existing Eclipse plug-ins that contain a transformation provider. Typically, a plug-in contains one transformation.
Creating transformation properties
You can create transformation properties in Eclipse plug-ins that contain transformations. Transformation properties refine the output that a transformation generates. You can specify values for these properties when you create or edit a transformation configuration.
Validating transformation properties
You can implement the validateContext method in a TransformationProvider class to validate the properties that you add to a transformation.
Enabling the creation of mapping models in transformations
You can specify that a transformation has the capability to create mapping models. By creating mapping models, you can specify alternate names for transformed artifacts. For example, you might create a mapping model that follows a platform-specific naming convention.
Managing mapping models in transformations
After you configure a transformation to create a mapping model, you can add code to a Java™ class in the transformation to create mapping models, to extract information from mapping models, and to validate the mapping parameters that the transformation context contains.
Organizing transformation elements
By organizing transformation elements, you can determine the order of events in the transformation. You can specify the utilities that a transformation runs, and specify the order in which the transformation service runs the elements in a transformation. You can also edit the properties of transformation utilities.
Specifying reverse transformations in plug-in manifest files
You can specify that a transformation is the reverse of another transformation. Reverse transformations enable you to recover changes to the source model or recover changes to the target model. This functionality is useful when you develop models concurrently. After you specify a reverse transformation, you can enable the reverse transformation in the transformation configurations that you create.
Showing or hiding transformations
You can show or hide transformations in the list of available transformations in the New Transformation Configuration wizard or transformation pop-up menus by binding transformations to Eclipse capabilities.
Configuring a runtime workbench to test transformations
You can invoke a runtime workbench to test and debug transformations. You might want to use the runtime workbench to avoid packaging the transformation plug-in before testing the transformation.
Creating transformation configurations
To run a transformation, you can create a transformation configuration. A transformation configuration contains the information that the transformation uses to generate the output that you expect. A transformation configuration also contains information that is specific to a particular type of transformation.
Adding pages to transformation configurations
You can create custom pages for transformation configurations. You might create these pages so that transformation users can specify values for the properties that you add to a transformation. When a transformation user creates a transformation configuration, the new pages are displayed in the transformation configuration editor or wizard.
Validating transformation configurations
You can validate a transformation configuration to ensure that the values in the configuration are valid according to the requirements of a transformation.
Running and rerunning transformations
You can run a transformation by applying a transformation configuration, by using command-line syntax, or by invoking the transformation API in application source code. You can also run multiple transformation configurations consecutively.
Debugging transformations
Several mechanisms are available for debugging transformations, such as generating debug logs or viewing the contents of the transformation context when you run a transformation. Your role as a transformation author or a transformation user determines which mechanisms you can use.
Customizing progress bars for transformations
You can customize a transformation to update the progress bar in a progress window as the transformation completes its tasks. This feature provides transformation users with more accurate information about how much work the transformation has completed.
Predefined properties for transformations
When you create a transformation, you can enable features or set values for properties by defining the corresponding property in the plugin.xml file of the plug-in that contains the transformation. Depending on how frequently the value changes, you can also update properties in the transformation context by using the transformation application programming interface (API).

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