Chapter 1: Introduction to EMF

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In this chapter, we introduce the Eclipse Modeling Framework (EMF). We mention most of the sources of information that are available on the subject, and we build a simple model as a practical demonstration of the use of EMF.

1.1 What is the Eclipse Modeling Framework?

Application development generally starts with consideration of the design model, then moves to more user interface oriented tasks. The Eclipse Modeling Framework is designed to ease the design and implementation of a structured model. The Java framework provides a code generation facility in order to keep the focus on the model itself and not on its implementation details. The key concepts underlying the framework are: meta-data, code generation, and default serialization.

1.1.1 Positioning of the framework

EMF was started as a Meta Object Facility (MOF) of the Object Management Group (OMG) implementation and has evolved to what it is now. EMF is an enhancement of MOF2.0. EMF is open source code that enhances the MOF 2.0 Ecore model and restructures its design in a way that is easy for the user.

The Eclipse Modeling Framework is part of the Model Driven Architecture (MDA). It is the current implementation of a portion of the MDA in the Eclipse family tools. The idea behind MDA it is to be able to develop and manage the whole application life cycle by putting the focus to the model. The model itself is described in a meta-model. Then, by using mappings, the model is used to generate software artefacts, which will implement the real system.

Two types of mappings are defined: Metadata Interchange, where documents like XML, DTD, and XSD are generated; and Metadata Interfaces, which target Java or any other language and generate IDL code. MDA is currently under the standardization process at the OMG.

1.1.2 Objectives

In this section we explain the main purpose of EMF and what it can currently be used for.

The problems EMF solves

EMF can be used to describe and build a model. Based on that definition, Java code can be generated and enhanced by the addition of higher level Java code. This implemented model can be used as the basis for any Java application development.

When not to use EMF

At the moment, EMF implements a subset of the MDA approach. As such, it does not contain all the mappings we would need to make and deploy an application at a company wide level, where XML, EAI, EJBs, Web services, and other technologies have to be combined.

1.1.3 Where to find documents and resources

EMF is still under development, but several sources of information are available These include:

• The EMF project page:

  EMF is one project of the Eclipse Tools Project, which is part of the global Eclipse Project, (http://www.eclipse.org). EMF is directly accessible at the URL:

  • http://www.eclipse.org/emf

  Available services range from code access and documents publishing, to community support, online code access using CVS, packaged code download, articles, user guides, tutorials, mailing list, newsgroup, and more.

• Newsgroup:

  The newsgroup server is news.eclipse.org. The newsgroup name for EMF is eclipse.tools.emf. It shows EMF relationship within the Eclipse Tools project.

• Mailing list:

  The mailing list for the EMF project is <[e-mail].>

Note 

You should send your questions to the newsgroup rather than to the mailing list.

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