在的Xtext，如何做一个自动生成多个模型文件的单个文件包含的信息。
考虑下面简单的Xtext语法。
grammar org.example.people.People with org.eclipse.xtext.common.Terminals
generate people "http://www.example.org/people/People"
People:
people+=Person*;
Person:
'person' name=ID ';';
在工作区展开我创建了有两个文件的项目， friends.people
// friends
person Alice;
person Bob;
和enemies.people
// enemies
person Malice;
person Rob;
如何自动生成一个文件，列出每个人的全球指数的变化是什么时候？
Alice
Bob
Malice
Rob
为便于日后参考，这里是通过组合克里斯蒂安·迪特里希给出的各种文献中得到的溶液。 需要注意的是该解决方案是Eclipse的依赖。
任何人谁该要求认定自己也许应该尝试找到建模问题的更好的方法。 例如一个单模型元素All产生，通过使用标准的API模型中的每个人都找到所需的列表。 这是一个独立的Eclipse，并要求下面的复杂性非。
在语法项目的发电机包，创建一个Java接口IPeopleGenerator延伸IGenerator2 。
package org.example.people.generator;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.xtext.generator.IFileSystemAccess2;
import org.eclipse.xtext.generator.IGenerator2;
import org.eclipse.xtext.generator.IGeneratorContext;
public interface IPeopleGenerator extends IGenerator2{
public void doGenerate(ResourceSet input, IFileSystemAccess2 fsa, IGeneratorContext context);
}
和编辑现有的发电机PeopleGenerator如下。
/*
* generated by Xtext 2.14.0
*/
package org.example.people.generator
import org.eclipse.emf.ecore.resource.Resource
import org.eclipse.emf.ecore.resource.ResourceSet
import org.eclipse.xtext.generator.IFileSystemAccess2
import org.eclipse.xtext.generator.IGeneratorContext
import org.example.people.people.Person
/**
* Generates code from your model files on save.
*
* See https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#code-generation
*/
class PeopleGenerator implements IPeopleGenerator {
override doGenerate(ResourceSet rs, IFileSystemAccess2 fsa, IGeneratorContext context) {
val people = rs.resources.map(r|r.allContents.toIterable.filter(Person)).flatten
fsa.generateFile("all.txt", people.compile)
}
override afterGenerate(Resource input, IFileSystemAccess2 fsa, IGeneratorContext context) {
}
override beforeGenerate(Resource input, IFileSystemAccess2 fsa, IGeneratorContext context) {
}
override doGenerate(Resource input, IFileSystemAccess2 fsa, IGeneratorContext context) {
}
def compile (Iterable<Person> entities) '''
«FOR e : entities»
«e.name»
«ENDFOR»
'''
}
并添加方法
def Class<? extends IPeopleGenerator> bindIPeopleGenerator () {
return PeopleGenerator
}
现有的运行模块PeopleRuntimeModule在语法项目。
工作需要在UI项目做org.example.people.ui 。 因此，这个解决方案是Eclipse的依赖性。
创建一个Java类org.example.people.ui.PeopleBuilderParticipant如下（复杂性是需要确保全球产生的文件只创建一次）。
package org.example.people.ui;
import java.util.List;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.xtext.builder.BuilderParticipant;
import org.eclipse.xtext.builder.EclipseResourceFileSystemAccess2;
import org.eclipse.xtext.builder.MonitorBasedCancelIndicator;
import org.eclipse.xtext.generator.GeneratorContext;
import org.eclipse.xtext.resource.IContainer;
import org.eclipse.xtext.resource.IResourceDescription;
import org.eclipse.xtext.resource.IResourceDescription.Delta;
import org.eclipse.xtext.resource.IResourceDescriptions;
import org.eclipse.xtext.resource.impl.ResourceDescriptionsProvider;
import org.example.people.generator.IPeopleGenerator;
import com.google.inject.Inject;
public class PeopleBuilderParticipant extends BuilderParticipant {
@Inject
private ResourceDescriptionsProvider resourceDescriptionsProvider;
@Inject
private IContainer.Manager containerManager;
@Inject(optional = true)
private IPeopleGenerator generator;
protected ThreadLocal<Boolean> buildSemaphor = new ThreadLocal<Boolean>();
@Override
public void build(IBuildContext context, IProgressMonitor monitor) throws CoreException {
buildSemaphor.set(false);
super.build(context, monitor);
}
@Override
protected void handleChangedContents(Delta delta, IBuildContext context,
EclipseResourceFileSystemAccess2 fileSystemAccess) throws CoreException {
super.handleChangedContents(delta, context, fileSystemAccess);
if (!buildSemaphor.get() && generator != null) {
invokeGenerator(delta, context, fileSystemAccess);
}
}
private void invokeGenerator(Delta delta, IBuildContext context, EclipseResourceFileSystemAccess2 access) {
buildSemaphor.set(true);
Resource resource = context.getResourceSet().getResource(delta.getUri(), true);
if (shouldGenerate(resource, context)) {
IResourceDescriptions index = resourceDescriptionsProvider.createResourceDescriptions();
IResourceDescription resDesc = index.getResourceDescription(resource.getURI());
List<IContainer> visibleContainers = containerManager.getVisibleContainers(resDesc, index);
for (IContainer c : visibleContainers) {
for (IResourceDescription rd : c.getResourceDescriptions()) {
context.getResourceSet().getResource(rd.getURI(), true);
}
}
MonitorBasedCancelIndicator cancelIndicator = new MonitorBasedCancelIndicator(
new NullProgressMonitor()); //maybe use reflection to read from fsa
GeneratorContext generatorContext = new GeneratorContext();
generatorContext.setCancelIndicator(cancelIndicator);
generator.doGenerate(context.getResourceSet(), access, generatorContext);
}
}
}
并通过加入结合此生成参与者
override Class<? extends IXtextBuilderParticipant> bindIXtextBuilderParticipant() {
return PeopleBuilderParticipant;
}
现有的UI模块org.example.people.ui.PeopleUiModule 。
我加入了验证代码fundagain的答案，以消除无效的资源。 然而，当最后一次修改资源是无效的，因为doGenerate不会被调用时无效，这将无法正常工作。 当任何有效的节约资源的无效资源将全部.txt被丢弃。
override doGenerate(ResourceSet rs, IFileSystemAccess2 fsa, IGeneratorContext context) {
var valid_rs = new ArrayList<Resource>
for(r : rs.resources)
if (( r as XtextResource)
.getResourceServiceProvider()
.getResourceValidator()
.validate(r,CheckMode.ALL, null)
.map(issue | issue.severity)
.filter[it === Severity.ERROR]
.size == 0)
valid_rs.add(r)
val types = valid_rs.map(r|r.allContents.toIterable.filter(Person)).flatten
fsa.generateFile("all.txt", people.compile)
}
