Patterns realize their maximum benefit from reuse and distribution. The Reusable Asset Specifications (RAS) standards provide a system to easily archive, search for, organize, document, and share pattern assets.
Rational's RAS capability provides a set of features and tools used to create default or specialized types of assets. Patterns are a unique type of RAS asset.
As patterns are created, the required meta files to support the RAS packaging are added to the pattern project. The meta files are known as RAS manifest files. The content of the manifest file is determined by a profile; patterns have their own pattern profile. The profile specifies the type of the meta file used to package and also restore RAS assets. Manifest files are identified by their RMD extension.
When a pattern plug-in project is created, it contains a pattern library and its pattern manifest file. As one or more patterns are added to the library with the pattern authoring tool, a pattern manifest is added for each pattern. At export, an additional default manifest file is added to package the library with its member patterns.
In addition to the packaging data, the manifest file stores the meta data that enables the RAS features. For example, it stores keywords for searching, short descriptions or instructions for the pattern applier, and group names (known as folders in the Asset Explorer view) for organizing patterns in the Pattern Explorer view and the Asset Explorer view.
All RAS assets are created and stored in the file system or in repositories by using a RAS export utility. Similarly, they are imported and unbundled to recreate the same relationships and structure by using a RAS import utility.
Repositories are added using the Asset Explorer view. However, the pattern repository is unique as it is always created for you whenever any pattern plug-ins are detected and available to your workspace. Patterns installed as plug-ins and patterns in other repositories all display in the pattern repository and the Pattern Explorer view.
Common RAS features, such as searching and adding groups (folders) are also available in the Pattern Explorer view. Thus, pattern functions can be accomplished without using the Asset Explorer view.
As mentioned, RAS assets are created as a result of a RAS export. Pattern projects do not export as pattern plug-ins unless the RAS option to create a deployable asset option is selected. Verification of each pattern in the project is essential before export. A project library that contains patterns that are not logically and semantically correct can be exported as deployable. However, at import the patterns may not appear in the Pattern Explorer view (and thus could not be applied). Verification of the pattern is done by testing each pattern in the run-time environment.
Pattern projects that you may want to work on at another time are saved to a non deployable asset. This type of asset is later imported as a project.