Yeoman: Call Sub-Generator With User-Supplied Arguments

Let’s consider you have a generator generator-blog (BlogGenerator) with two sub generators (blog-server and blog-client):

app\index.js
client\index.js
server\index.js

So when you run yo blog you what to ask the user for some options and run (optionally) sub generators, right?

To run a subgenerator you need to call this.invoke("generator_namespace", {options: {}}).
The second argument we passed can have options field – it’s options object which will be passed to the generator.

In app\index.js:

BlogGenerator.prototype.askFor = function askFor() {
  var cb = this.async();

  // have Yeoman greet the user.
  console.log(this.yeoman);

  var prompts = [{
    name: 'appName',
    message: 'Enter your app name',
    default: 'MyBlog'
  }, {
    type: 'confirm',
    name: 'createServer',
    message: 'Would you like to create server project?',
    default: true
  }, {
    type: 'confirm',
    name: 'createClient',
    message: 'Whould you like to create client project?',
    default: true
  }];

  this.prompt(prompts, function (props) {
    this.appName = props.appName;
    this.createServer = props.createServer;
    this.createClient = props.createClient;

    cb();
  }.bind(this));
}

BlogGenerator.prototype.main = function app() {
  if (this.createClient) {
    // Here: we'are calling the nested generator (via 'invoke' with options)
    this.invoke("blog:client", {options: {nested: true, appName: this.appName}});
  }
  if (this.createServer) {
    this.invoke("blog:server", {options: {nested: true, appName: this.appName}});
  }
};

In client\index.js:

var BlogGenerator = module.exports = function BlogGenerator(args, options, config) {
  var that = this;
  yeoman.Base.apply(this, arguments);
  // in this.options we have the object passed to 'invoke' in app/index.js:
  this.appName = that.options.appName;
  this.nested  = that.options.nested;
};

BlogGenerator .prototype.askFor = function askFor() {
  var cb = this.async();

  if (!this.options.nested) {
    console.log(this.yeoman);
  }
}

UPDATE 2015-12-21:
Using invoke is deprecated now and should be replaced with composeWith. But it’s not as easy as it could be. The main difference between invoke and composeWith is that now you have no ability to control subgenerators. You could only declare using them.
Here’s how main method from above should look like:

BlogGenerator.prototype.main = function app() {
  if (this.createClient) {
    this.composeWith("blog:client", { 
        options: { 
          nested: true, 
          appName: this.appName
        } 
      }, {
        local: require.resolve("./../client")
      });
  }
  if (this.createServer) {
    this.composeWith("blog:server", { 
        options: { 
          nested: true, 
          appName: this.appName
        } 
      }, {
        local: require.resolve("./../server")
      });
  }
};

Also I removed replaced yeoman.generators.Base with yeoman.Base.