attach_heads.js

/**
 * Task: attach_heads
 * Description: Set the heads for all themes declared in themes.json
 */

module.exports = function(grunt) {
  'use strict';

  var fs = require('fs');
  var path = require('path');

  grunt.registerTask('attach_heads', 'Set the heads recursively for all JS/CSS in themes.json', function() {
      var themeMetaObj = grunt.file.readJSON('themes.json');
      var pkgObject = grunt.file.readJSON('package.json');
      var banner =
            ' (v.'+pkgObject.version+')\n' +
            ' *  by '+pkgObject.name+' \n' +
            ' *  '+pkgObject.homepage+'\n' +
            ' *  Copyright (c) '+grunt.template.today("yyyy")+' '+pkgObject.name+'\n' +
            ' *  \n' +
            ' *  ============================================= */ \n';

      // iterate over the themeMetaObj for number of themes (default is declared here as well)
      for ( var key in themeMetaObj ) {
          var thisTheme = themeMetaObj[key];
          var headObj = {
            'devCss' : '../'+thisTheme._name+'/assets/css/main.css',
            'prodCss' : '../'+thisTheme._name+'/assets/css/main.min.css',
            'devJs' : '../'+thisTheme._name+'/assets/js/scripts.js',
            'prodJs' : '../'+thisTheme._name+'/assets/js/scripts.min.js'
          };
          var thisBanner = '';
          thisBanner = '/*! ================================================ \n' +
            ' * \n' +
            ' *  '+thisTheme._long_name+' Theme ' +
            banner;
          for ( var fileKey in headObj ) {
            var thisFile = headObj[fileKey];
            var content = grunt.file.read( thisFile );
            content = thisBanner + content;
            grunt.file.write( thisFile, content );
            grunt.log.writeln('"' + thisFile + '" updated with latest head.');
          }
      }
  });
};

grunt.js

/*jshint laxcomma:true */
module.exports = function(grunt) {
  grunt.initConfig({
    pkg: '<json:package.json>',
    themeMeta: '<json:themes.json>',
    lint: {
      files: ['assets/js/_*.js', 'grunt.js']
    },
    recess: {
      // set dynamically in generateThemeConfig()
    },
    concat: {
      // set dynamically in generateThemeConfig()

      // full listing of original bootstrap plugins
        // "_js_includes" : [
        //   "assets/js/plugins/bootstrap/bootstrap-transition.js",
        //   "assets/js/plugins/bootstrap/bootstrap-alert.js",
        //   "assets/js/plugins/bootstrap/bootstrap-button.js",
        //   "assets/js/plugins/bootstrap/bootstrap-carousel.js",
        //   "assets/js/plugins/bootstrap/bootstrap-collapse.js",
        //   "assets/js/plugins/bootstrap/bootstrap-dropdown.js",
        //   "assets/js/plugins/bootstrap/bootstrap-modal.js",
        //   "assets/js/plugins/bootstrap/bootstrap-tooltip.js",
        //   "assets/js/plugins/bootstrap/bootstrap-popover.js",
        //   "assets/js/plugins/bootstrap/bootstrap-scrollspy.js",
        //   "assets/js/plugins/bootstrap/bootstrap-tab.js",
        //   "assets/js/plugins/bootstrap/bootstrap-typeahead.js",
        //   "assets/js/plugins/*.js",
        //   "assets/js/_*.js"
        // ]
    },
    min: {
      // set dynamically in generateThemeConfig()
    },
    mincss: {
      // set dynamically in generateThemeConfig()
    },
    watch: {
      // set dynamically in generateThemeConfig()
    }
  });

  grunt.loadTasks('build/tasks');
  grunt.loadNpmTasks('grunt-contrib');
  grunt.loadNpmTasks('grunt-recess');

    function generateThemeConfig( registerThemeTask ) {
      var i
          , len
          , o
          , allTasksLen
          , msg
          , themeMetaObj = grunt.file.readJSON('themes.json')
          , pkgObject = grunt.file.readJSON('package.json')
          // tasks performed on all themes are declared in package.json
          , themeSpecificTasks = pkgObject.themeSpecificTasks;

      // iterate over the themeMetaObj for number of themes (default is declared here as well)
      for ( var key in themeMetaObj ) {
          var thisTheme = themeMetaObj[key]
              , taskArray = [];

            grunt.config( 'recess.'+thisTheme._name+'DevCss', {
                src: 'child_themes/'+thisTheme._name+'/master.less',
                dest: '../'+thisTheme._name+'/assets/css/main.css',
                options: {
                  compile: true
                }
            });

            grunt.config( 'recess.'+thisTheme._name+'ProdCss', {
                src: 'child_themes/'+thisTheme._name+'/master.less',
                dest: '../'+thisTheme._name+'/assets/css/main.min.css',
                options: {
                  compile: true,
                  compress: true
                }
            });

            grunt.config( 'concat.'+thisTheme._name, {
                src: thisTheme._js_includes,
                dest: '../'+thisTheme._name+'/assets/js/scripts.js'
            });

            grunt.config( 'min.'+thisTheme._name, {
                src: thisTheme._js_includes,
                dest: '../'+thisTheme._name+'/assets/js/scripts.min.js'
            });
      }

      registerThemeTask();
    }


    // register themes as a callback to ensure config is generated first
    generateThemeConfig( function() {

          var themeMetaObj = grunt.file.readJSON('themes.json')
          , pkgObject = grunt.file.readJSON('package.json')
          // tasks performed on all themes are declared in package.json
          // in attribute name `themeSpecificTasks`
          , themeSpecificTasks = pkgObject.themeSpecificTasks
          , allTaskArray = [];

          // iterate over the themeMetaObj for number of themes (default is declared here as well)
          for ( var key in themeMetaObj ) {
              var thisTheme = themeMetaObj[key]
                  , taskArray = [];

              // iterate over preLoopTasks (set in package.json) and push them
              // into the array for this theme
              for ( var preLoopTasksKey in pkgObject.preLoopTasks ) {
                taskArray.push( pkgObject.preLoopTasks[preLoopTasksKey] );
              }
              // iterate over theme-specific tasks and push them into
              // theme-specific task array
              for ( var tasksKey in themeSpecificTasks ) {
                var thisTaskObj = themeSpecificTasks[tasksKey];
                // grunt.log.writeln( grunt.log.writeflags( thisTaskObj, 'thisTaskObj') );
                // take thisTask and check to see if it has an array of length
                // if > 0, then we need multiple "sub-tasks" and we assign them
                if ( thisTaskObj.length > 0 ) {
                  for (var x = 0; x < thisTaskObj.length; x++) {
                      taskArray.push( tasksKey+':'+thisTheme._name+thisTaskObj[x] );
                  }
                } else {
                  taskArray.push( tasksKey+':'+thisTheme._name );
                }
              }
              allTaskArray = allTaskArray.concat( taskArray );

              // iterate over postLoopTasks (set in package.json) and push them
              // into the array for this theme
              for ( var postLoopTasksKey in pkgObject.postLoopTasks ) {
                taskArray.push( pkgObject.postLoopTasks[postLoopTasksKey] );
              }

              grunt.registerTask( 'theme:'+thisTheme._name, taskArray);
          }

      // function to find and remove elements from an array
      function removeArr(arr) {
          var what, a = arguments, L = a.length, ax;
          while (L > 1 && arr.length) {
              what = a[--L];
              while ((ax= arr.indexOf(what)) !== -1) {
                  arr.splice(ax, 1);
              }
          }
          return arr;
      }

      for ( var loopTask in pkgObject.preLoopTasks ) {
        removeArr( allTaskArray, pkgObject.preLoopTasks[loopTask]);
        allTaskArray.unshift( pkgObject.preLoopTasks[loopTask] );
      }

      allTaskArray = allTaskArray.concat( pkgObject.postLoopTasks );

      grunt.registerTask( 'default', allTaskArray );

    });

};

package.json

{
  "name": "example.com",
  "description": "Tagline here",
  "version": "1.0",
  "homepage": "http://example.com",
  "author": "you@example.com",
  "dependencies": {
    "grunt": "~0.3.15",
    "grunt-contrib": "~0.2.0",
    "grunt-recess": "~0.1.1",
    "uglify-js": "~1.3.3",
    "jshint": "~0.5.9"
  },
  "devDependencies": {},
  "preLoopTasks" : [
    "lint"
  ],
  "postLoopTasks" : [
    "enqueue_ver",
    "attach_heads"
  ],
  "themeSpecificTasks" : {
    "recess" : [
      "DevCss",
      "ProdCss"
    ],
    "concat" : [],
    "min" : []
  },
  "attach_heads_to" : {
    "devCss" : "/assets/css/main.css",
    "prodCss" : "/assets/css/main.min.css",
    "devJs" : "/assets/js/scripts.js",
    "prodJs" : "/assets/js/scripts.min.js"
  }
}

themes.json

{
    "default" : {
        "_name"        : "default",
        "_long_name"   : "Default",
        "_js_includes" : [
          "assets/js/plugins/bootstrap/bootstrap-transition.js",
          "assets/js/plugins/bootstrap/bootstrap-alert.js",
          "assets/js/plugins/bootstrap/bootstrap-button.js",
          "assets/js/plugins/bootstrap/bootstrap-carousel.js",
          "assets/js/plugins/bootstrap/bootstrap-collapse.js",
          "assets/js/plugins/bootstrap/bootstrap-dropdown.js",
          "assets/js/plugins/bootstrap/bootstrap-modal.js",
          "assets/js/plugins/bootstrap/bootstrap-tooltip.js",
          "assets/js/plugins/bootstrap/bootstrap-popover.js",
          "assets/js/plugins/bootstrap/bootstrap-scrollspy.js",
          "assets/js/plugins/bootstrap/bootstrap-tab.js",
          "assets/js/plugins/bootstrap/bootstrap-typeahead.js",
          "assets/js/plugins/*.js",
          "assets/js/_*.js"
        ]
    },
    "foo" : {
        "_name"        : "foo",
        "_long_name"   : "Foo",
        "_js_includes" : [
            "assets/js/plugins/bootstrap/bootstrap-transition.js",
            "assets/js/plugins/bootstrap/bootstrap-alert.js",
            "assets/js/plugins/bootstrap/bootstrap-button.js",
            "assets/js/plugins/bootstrap/bootstrap-collapse.js",
            "assets/js/plugins/bootstrap/bootstrap-dropdown.js",
            "assets/js/plugins/bootstrap/bootstrap-tooltip.js",
            "assets/js/plugins/bootstrap/bootstrap-popover.js",
            "assets/js/plugins/*.js",
            "assets/js/_*.js"
        ]
    },
    "bar" : {
        "_name"        : "bar",
        "_long_name"   : "Bar",
        "_js_includes" : [
            "assets/js/plugins/bootstrap/bootstrap-transition.js",
            "assets/js/plugins/bootstrap/bootstrap-alert.js",
            "assets/js/plugins/bootstrap/bootstrap-button.js",
            "assets/js/plugins/bootstrap/bootstrap-collapse.js",
            "assets/js/plugins/bootstrap/bootstrap-dropdown.js",
            "assets/js/plugins/bootstrap/bootstrap-tooltip.js",
            "assets/js/plugins/bootstrap/bootstrap-popover.js",
            "assets/js/plugins/*.js",
            "assets/js/_*.js"
        ]
    }
}