XMF: Xtend-centric meta-model specification

Using Xtend active annotations, the following code is converted automagically into a EMF-based meta-model and API.

• aimed at programmers who are familiar with EMF
• API is generated automatically while the programer writes code in the editor
• no *.genmodel files required
• no *.ecore files required
• just plain Xtend

This project is currently just a proof-of-concept. It only covers a very small portion of EMF.

Currently supported:

• @XMFPackage creates EPackage + EFactory classes
• @XMF for classes of the meta model
• inheritance using classes and abstract classes (currently no interfaces, but it will change soon)
• @Contained for containment relation
• @Invariant marks validation methods. XMF will automatically create the Validator class as necessary
• Non-XMF datatypes are treated as attributes
• XMF datatype is treated as a reference
• @DerivedAttribute for attributes whose value is computed in a method
• List<T> is treated as a attribute/reference of cardinality 0..* and mapped to EList<T>
• public methods are treated as EOperations
• non-public method are ignored

Example meta model:

@XMFPackage("http://some/eNS_URI")

@XMF abstract class NamedEntity {

    @ID String name

    @Invariant("name must be smaller than 10 characters")
    def nameSizeConstraint() {
        name.length < 10
    }

    @Invariant("name cannot be empty")
    def nameNotEmpty() {
        ! name.empty
    }
}

@XMF class User extends NamedEntity {
    List<String> phones
    @OppositeOf("users") Group group
    @Contained Account userAccount

    def someOperation() {
        ...
    }

    private def helperMethod() {
        ...
    }
}

@XMF class Group extends NamedEntity {
    @Contained List<User> users
    @DerivedAttribute def paidUsers() {
        users.filter[salary > 0]
    }
}

@XMF class Account {
    int salary = 0
}