Extending the Rodin Database

There are different ways to extend the Rodin Database:

• adding a new element.

• adding a new attribute.

Adding a New Attribute to Existing Elements

Declare a New Attribute

The extension point org.rodinp.core.attributeTypes to declare a new attribute.

In the example below, we assume that the extensions are developed within a plug-in project with name org.eventb.developer.examples

The following extension declares a new string attribute.

<extension
        point="org.rodinp.core.attributeTypes">
     <attributeType
           id="stringAttr"
           kind="string"
           name="%eventBStringAttribute">
     </attributeType>
 </extension>

• The attribute has an ID (which should be always unique) which also contain the project name, i.e. org.eventb.developer.examples.stringAttr. This unique ID will be used for access the value corresponding to this attribute of an element later.

• The name of the attribute is a string that could be externalised to be used for displaying to the users in the future.

• There are five different attribute kinds: boolean, handle, integer, long, string.

Access (Programmatically) the Newly Created Attribute

After declaring the attribute with the ID and the kind of the attribute, we need to access the value corresponding to the attribute of any internal element.

Firstly, we need to get the corresponding Java attribute type, this corresponding to the

• boolean: org.rodinp.core.IAttributeTypes.Boolean

• handle: org.rodinp.core.IAttributeTypes.Handle

• int: org.rodinp.core.IAttributeTypes.Integer

RodinCore. Depending on the kind of the attribute, one can use one of the following method to access the value corresponding to the attribute of any