Difference between revisions of "CDO/Preparing EMF Models"

Revision as of 07:00, 21 October 2007

Create an Ecore Model

There's not much to say about this step. The .ecore file for CDO models is the same as for pure EMF models. The only differences are in the Java code that the EMF generator will produce, as you will see in the next step.

The model1 example model in the usual Ecore model editor looks like follows:

The XML form of this Ecore model is:

<?xml version="1.0" encoding="UTF-8"?>
<ecore:EPackage xmi:version="2.0"
    xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" name="model1"
    nsURI="http://www.eclipse.org/emf/CDO/tests/model1/1.0.0" nsPrefix="model1">
  <eClassifiers xsi:type="ecore:EClass" name="Address">
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="street" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="city" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Company" eSuperTypes="#//Address">
    <eStructuralFeatures xsi:type="ecore:EReference" name="categories" upperBound="-1"
        eType="#//Category" containment="true"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="suppliers" upperBound="-1"
        eType="#//Supplier" containment="true"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="customers" upperBound="-1"
        eType="#//Customer" containment="true"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="purchaseOrders" upperBound="-1"
        eType="#//PurchaseOrder" containment="true"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="salesOrders" upperBound="-1"
        eType="#//SalesOrder" containment="true"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Supplier" eSuperTypes="#//Address">
    <eStructuralFeatures xsi:type="ecore:EReference" name="purchaseOrders" upperBound="-1"
        eType="#//PurchaseOrder" eOpposite="#//PurchaseOrder/supplier"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Customer" eSuperTypes="#//Address">
    <eStructuralFeatures xsi:type="ecore:EReference" name="salesOrders" unique="false"
        upperBound="-1" eType="#//SalesOrder" eOpposite="#//SalesOrder/customer"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Order">
    <eStructuralFeatures xsi:type="ecore:EReference" name="orderDetails" upperBound="-1"
        eType="#//OrderDetail" containment="true" eOpposite="#//OrderDetail/order"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="OrderDetail">
    <eStructuralFeatures xsi:type="ecore:EReference" name="order" lowerBound="1" eType="#//Order"
        eOpposite="#//Order/orderDetails"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="product" eType="#//Product"
        eOpposite="#//Product/orderDetails"/>
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="price" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EFloat"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="PurchaseOrder" eSuperTypes="#//Order">
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="date" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EDate"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="supplier" lowerBound="1"
        eType="#//Supplier" eOpposite="#//Supplier/purchaseOrders"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="SalesOrder" eSuperTypes="#//Order">
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="id" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="customer" lowerBound="1"
        eType="#//Customer" eOpposite="#//Customer/salesOrders"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Category">
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="categories" upperBound="-1"
        eType="#//Category" containment="true"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="products" upperBound="-1"
        eType="#//Product" containment="true"/>
  </eClassifiers>
  <eClassifiers xsi:type="ecore:EClass" name="Product">
    <eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
    <eStructuralFeatures xsi:type="ecore:EReference" name="orderDetails" upperBound="-1"
        eType="#//OrderDetail" eOpposite="#//OrderDetail/product"/>
  </eClassifiers>
</ecore:EPackage>

Create the GenModel

The EMF generator model for your Ecore model is much like a usual Genodel except for three differences:

• The Feature Delegation property must be set to Reflective
• The Root Extends Class property must be set to org.eclipse.emf.internal.cdo.CDOObjectImpl
• The Root Extends Interface property can be set to org.eclipse.emf.cdo.CDOObject

Note that you do not need to generate an editor if you want to use your model with the CDO User Interface. A dedicated model editor is only needed if you plan to use your model with normal XML based files as well. Even in this scenario it could be simpler to use the EMF Reflective Model Editor though.

The XML form of this generator model is:

<?xml version="1.0" encoding="UTF-8"?>
<genmodel:GenModel xmi:version="2.0"
    xmlns:xmi="http://www.omg.org/XMI" xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore"
    xmlns:genmodel="http://www.eclipse.org/emf/2002/GenModel" modelDirectory="/org.eclipse.emf.cdo.tests.model1/src"
    modelPluginID="org.eclipse.emf.cdo.tests.model1" modelName="Model1" rootExtendsInterface="org.eclipse.emf.cdo.CDOObject"
    rootExtendsClass="org.eclipse.emf.internal.cdo.CDOObjectImpl" reflectiveDelegation="true"
    testsDirectory="" importerID="org.eclipse.emf.importer.ecore" featureDelegation="Reflective"
    complianceLevel="5.0">
  <foreignModel>model1.ecore</foreignModel>
  <genPackages prefix="Model1" basePackage="org.eclipse.emf.cdo.tests" disposableProviderFactory="true"
      ecorePackage="model1.ecore#/">
    <genClasses ecoreClass="model1.ecore#//Supplier">
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//Supplier/name"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//PurchaseOrder">
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//PurchaseOrder/date"/>
      <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference model1.ecore#//PurchaseOrder/supplier"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//OrderDetail">
      <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference model1.ecore#//OrderDetail/product"/>
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//OrderDetail/price"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//Product">
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//Product/name"/>
      <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference model1.ecore#//Product/orderDetails"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//Category">
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//Category/name"/>
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Category/categories"/>
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Category/products"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//Company">
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Company/categories"/>
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Company/suppliers"/>
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Company/purchaseOrders"/>
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Company/customers"/>
      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference model1.ecore#//Company/salesOrders"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//Customer">
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//Customer/name"/>
      <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference model1.ecore#//Customer/salesOrders"/>
    </genClasses>
    <genClasses ecoreClass="model1.ecore#//SalesOrder">
      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute model1.ecore#//SalesOrder/id"/>
      <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference model1.ecore#//SalesOrder/customer"/>
    </genClasses>
  </genPackages>
</genmodel:GenModel>

Generate The Model

Generate the Java code for your model like you are used to do it:

The result of the generation can look similar to this (some artifacts are hidden to declutter the Package Explorer):

Modify the Plugin Manifest

At runtime the CDO client needs to determine whether a given EPackage (your model) has been generated for CDO or not. You can declaratively specify this information by contributing to the org.eclipse.emf.cdo.persistent_package extension point, much like you announce the model to EMF via the org.eclipse.emf.cdo.persistent_package extension point:

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.3"?>

<plugin>

  <extension point="org.eclipse.emf.ecore.generated_package">
    <package 
       uri = "http://www.eclipse.org/emf/CDO/tests/model1/1.0.0" 
       class = "org.eclipse.emf.cdo.tests.model1.Model1Package"
       genModel = "model/model1.genmodel"/> 
  </extension>
  
  <extension point="org.eclipse.emf.cdo.persistent_package">
    <package
       uri = "http://www.eclipse.org/emf/CDO/tests/model1/1.0.0"/>
  </extension>

</plugin>

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