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<p>Access to models generated with the <a href="http://www.eclipse.org/modeling/emf/">Eclipse Modeling Framework</a> is easy in Groovy with the help of Groovy Beans and GPath.</p>

<p>As an example we use the <a href="http://help.eclipse.org/help32/index.jsp?topic=/org.eclipse.emf.doc/tutorials/clibmod/clibmod.html">EMF tutorial</a>. This model contains three classes Book, Writer and Library and an enumeration BookCategory. From this model EMF generates Java code. There are two special classes: a package class and a factory class. We need the package class for reading the model. We have to instantiate it and load a file with data as following.</p>

<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
LibraryPackage.eINSTANCE
def resource = new XMIResourceImpl(URI.createURI('hardboiled.library'))
resource.load(null)
Library library = (Library) resource.contents\[0\]        // get the root element
</pre></td></tr></table>

<p>Now we are able to query the model using standard Groovy. For example</p>

<p>prints out all books. We can print out all the books with less than 240 pages with the following statement.</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
println library.books.grep { it.pages &lt; 240 }.title.join(", ")
</pre></td></tr></table>

<p>All the objects in an EMF model are constructed with methods from a factory (LibraryFactory in this example). The <a href="http://www.dinkla.net/groovy/emf.html">Groovy EMF Builder</a> provides an interface for constructing models and model elements. It takes an EMF factory as an argument.  In the following snippet three objects are created in the model: a Library, a Writer and a Book. </p>

<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
def builder = new EMFBuilder(LibraryFactory)
def writer
def library = builder.Library( name : 'Hardboiled Library') {
  writers {
    writer = Writer( name : 'Raymond Chandler')     
  }
  books { 
             Book ( title: 'The Big Sleep', pages: 234, category: BookCategory.MYSTERY_LITERAL, author: writer)     
  }
}
</pre></td></tr></table>

<p>The braces  indicate the containment relationships writers and books of the class Library.<br />
See the homepage of the <a href="http://www.dinkla.net/groovy/emf.html">Groovy EMF Builder</a> for further details.</p>