Question

我正在研究xtext项目，我正在通过.xtext文件生成对象。我想为其中一个生成的对象添加新属性。我在http://christiandietrich.wordpress.com/2011/07/22/customizing-xtext-metamodel-inference-using-xtend2/看到了以下代码在ObjectValue中生成临时变量但我希望temp属于MyObject类型。

怎么做？我在哪里可以阅读它？

import org.eclipse.emf.codegen.ecore.genmodel.GenModelPackage
import org.eclipse.emf.common.util.BasicEMap$Entry
import org.eclipse.emf.ecore.EClass
import org.eclipse.emf.ecore.EPackage
import org.eclipse.emf.ecore.EcoreFactory
import org.eclipse.emf.ecore.EcorePackage
import org.eclipse.xtext.GeneratedMetamodel
import org.eclipse.xtext.xtext.ecoreInference.IXtext2EcorePostProcessor

class CodeGeneratorClass implements IXtext2EcorePostProcessor {

    override process(GeneratedMetamodel metamodel) {
        metamodel.EPackage.process
    }

    def process(EPackage p) {
        for (c : p.EClassifiers.filter(typeof(EClass))) {
            if (c.name == "ObjectValue") {
                c.handle
            }
        }
    }

    def handle (EClass c) {
    val attr = EcoreFactory::eINSTANCE.createEAttribute
    attr.name = "temp"
    attr.EType = EcorePackage::eINSTANCE.EString
    c.EStructuralFeatures += attr
}
}

Answer 1

首先：MyObject必须由EClass或EDataType来描述。普通的Java对象不会这样做。

如果MyObject是EDataType，那么您必须在EAttribute方法中添加handle。您的handle方法几乎正确，只需调整EType：

attr.EType = MyPackage::eINSTANCE.MyObject

否则：如果MyObject是EClass，那么您必须添加EReference而不是EAttribute。此案例的handle方法如下所示：

def handleReference(EClass c){
    val ref = EcoreFactory::eINSTANCE.createEReference
    ref.name = "temp"
    ref.EType = MyPackage::eINSTANCE.MyObject
    c.EStructuralFeatures += ref
}

修改

为了定义一个新的最小EDataType并将其连接到模型中，以下代码片段应该可以工作：

def void process(GeneratedMetamodel it){ // create new dynamic EDataType val dataType = EcoreFactory::eINSTANCE.createEDataType => [ name = 'MyObject' instanceTypeName = 'java.package.with.MyObject' ] // register new EDataType in own model package EPackage.EClassifiers += dataType // attach as EAttribute to appropriate EClasses EPackage.EClassifiers.filter(typeof(EClass)).filter[name == 'ObjectValue'].forEach[ EStructuralFeatures += EcoreFactory::eINSTANCE.createEAttribute => [ name = "temp" EType = dataType ] ] }

代码在xtext项目中使用xtend生成

1 个答案: