Why the _directory function is called four times in a yeoman.generators.Base subclass? -

here how extend yeoman generator base class

module.exports = yeoman.generators.base.extend({   prompting: function () {     var done = this.async();      // have yeoman greet user.     this.log(yosay(       'welcome cool ' + chalk.red('generator-zeetings') + ' generator!'     ));      var prompts = [{       ...       }];      this.prompt(prompts, function (props) {       this.props = props;       // ...       done();     }.bind(this));   },    _directory: function (source, destination) {       // simplified question       var src = path.join(source, 'index.html');       var dest = path.join(destination, 'final.html');       console.log('copy ' + src + ' ' + dest);       this.fs.copytpl(         this.templatepath(src),         this.destinationpath(dest),         this.props       );    },    prepareapp: function () {     this._directory(this.templatepath(), this.destinationroot('app'));   },    preparedata: function () {     this._directory(this.templatepath(), this.destinationroot('data'));   },    writing: function () {     this.prepareapp();     this.preparedata();   }, }); 

i find reason helper function _directory called 4 times.

i expected function called twice, 1 app , other folder data, writing function.

it turns out if prepend _ appendapp , appenddata, generator behave expected.

what want understand are:

1) don't seem find behaviour documented on yeoman website. behaviour ('calling every public method in subclass') expected?

2) if expected behaviour, how can control order these public methods called?

refer documentation: http://yeoman.io/authoring/running-context.html

each function in yeoman-generator task. tasks run automatically , ordered based on priorities (priority defined function/object name).

functions names starting underscore considered private , won't runned.