Question

在Xtext中，一个人如何自动生成一个包含来自多个模型文件的信息的文件。

考虑以下简单的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 ';';

在启动的工作区中，我创建一个包含两个文件的项目friends.people

// friends
person Alice;
person Bob;

和enemies.people

// enemies
person Malice;
person Rob;

当全局索引更改时，如何自动生成列出所有人的单个文件？

Alice
Bob
Malice
Rob

Answer 1

为便于将来参考，以下是结合Christian Dietrich提供的各种参考而获得的解决方案。请注意，该解决方案取决于Eclipse。

任何发现自己有此要求的人都应该尝试找到更好的建模问题的方法。例如，单例模型元素All通过使用标准API在模型中查找每个人来生成所需列表。这独立于Eclipse，并且不需要以下复杂性。

在语法项目的生成器包中，创建扩展IPeopleGenerator的Java接口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);
}

并按如下所示编辑现有的生成器PeopleGenerator。

/*
 * 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
}

转到语法项目中的现有运行时模块PeopleRuntimeModule。

需要在UI项目org.example.people.ui中完成工作。因此，此解决方案取决于Eclipse。

按如下方式创建Java类org.example.people.ui.PeopleBuilderParticipant（复杂性是需要确保仅全局创建文件一次创建）。。

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);
        }
    }

}

并通过添加

来绑定此构建参与者

override  Class<? extends IXtextBuilderParticipant>  bindIXtextBuilderParticipant() {       
    return PeopleBuilderParticipant;
}

到现有的UI模块org.example.people.ui.PeopleUiModule。

Answer 2

我将验证码添加到Fundaaga的答案中，以消除无效资源。但是，当最后修改的资源无效时，这将不起作用，因为无效时不会调用doGenerate。保存任何有效资源后，无效资源将从all.txt中丢弃。

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)
}

Xtext全局自动生成

2 个答案: