yeoman when

yeoman.js

  var prompts = [
      {
        type: 'list',
        name: 'type',
        message: 'What category does this belong to?',
        choices: ['blogs', 'books', 'podcasts', 'talks', 'tools', 'videos']
      },
      {
        when: function (response) {
          return response.type == 'blogs';
        },
        type: 'input',
        name: 'blog_name',
        message: 'Name of the blog',
      },
      {
        type: 'input',
        name: 'title',
        message: 'Title',
      },
      {
        type: 'input',
        name: 'description',
        message: 'Description',
      },
    ];