How do I include Xtext generator in my Maven project?

Question

I am currently building a framework which would benefit from having a DSL for creating a configuration file, so I created one using Xtext.

Now I want to add a dependency to the classes that I have created so that I can generate configurations at runtime, but on Xtext's site it looks like the only two cases for integration are:

When I want CI for the language itself;
When I want to include a plugin that would generate code at build time.

How can I use the generator that I wrote in Xtext at runtime in my Maven project?

Christian Dietrich · Accepted Answer · 2017-10-11T09:23:16.433

For CI for Xtext itself simpy use the new project wizard and select Maven as build system on the second page of the project. To build your model files have a look that the xtext-maven-plugin e.g. as used here https://github.com/xtext/maven-xtext-example/blob/master/example-project/pom.xml or here https://github.com/cdietrich/xtext-maven-example/blob/master/org.xtext.example.mydsl.model/pom.xml

If you simply want to read a model file and call the generator

package org.eclipse.xtext.example.domainmodel;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.xtext.generator.GeneratorContext;
import org.eclipse.xtext.generator.GeneratorDelegate;
import org.eclipse.xtext.generator.IGeneratorContext;
import org.eclipse.xtext.generator.JavaIoFileSystemAccess;
import org.eclipse.xtext.util.CancelIndicator;
import org.eclipse.xtext.validation.CheckMode;
import org.eclipse.xtext.validation.IResourceValidator;
import org.eclipse.xtext.validation.Issue;

import com.google.common.collect.Lists;
import com.google.inject.Injector;

/**
 * @author dietrich - Initial contribution and API
 */
public class Main {

    public static void main(String[] args) {
        // TODO traverse directory
        List<String> files = Lists.newArrayList("model/a.dmodel", "model/b.dmodel");
        Injector injector = new DomainmodelStandaloneSetup().createInjectorAndDoEMFRegistration();
        ResourceSet rs = injector.getInstance(ResourceSet.class);
        ArrayList<Resource> resources = Lists.newArrayList();
        for (String file : files) {
            Resource r = rs.getResource(URI.createFileURI(file), true);
            resources.add(r);
        }

        IResourceValidator validator = injector.getInstance(IResourceValidator.class);
        for (Resource r : resources) {
            List<Issue> issues = validator.validate(r, CheckMode.ALL, CancelIndicator.NullImpl);
            for (Issue i : issues) {
                System.out.println(i);
            }
        }

        GeneratorDelegate generator = injector.getInstance(GeneratorDelegate.class);
        JavaIoFileSystemAccess fsa = injector.getInstance(JavaIoFileSystemAccess.class);
        fsa.setOutputPath("src-gen-code/");
        GeneratorContext context = new GeneratorContext();
        context.setCancelIndicator(CancelIndicator.NullImpl);

        for (Resource r : resources) {
            generator.generate(r, fsa, context);
        }
    }

}

This does not look like my use case I think. I want to embed the generator so that I can use it inside another java class in the Maven project. This looks like build-time generation. — Hristo Vrigazov, Oct 11 '17 at 09:12
I don't know how to explain it more clearly. I want to have a packaged maven dependency that I can add to my project and from the code itself to use the generator. The example shown is adding a maven plugin that would generate code during build. — Hristo Vrigazov, Oct 11 '17 at 09:15
so you ask: how to i read 1 or multiple dsl files from java code and then call the code generator on these model files? — Christian Dietrich, Oct 11 '17 at 09:17
Exactly, how do I use the whole pipeline - I just give as input the text file with the program in my DSL and have a class which generates files based on this, but to do it imperatively (from my code), not in the build — Hristo Vrigazov, Oct 11 '17 at 09:18
Fantastic, thanks! I thought I should use Guice in some way, but was not sure which classes exactly I should instantiate. Awesome! — Hristo Vrigazov, Oct 11 '17 at 09:28

How do I include Xtext generator in my Maven project?

1 Answers1