Compose controller functions

composeControllers.js

/**
 *
 * Late night framework experiment with @pmarabeas
 * 
 */


'use strict';

var angular = require('angular');


function compose(/** controllers */) {
  var allControllers       = Array.prototype.slice.call(arguments),
      combinedDependencies = [],
      functions            = [],
      argumentMappings     = [];

  allControllers
    .filter(function(ctrl) {
      return angular.isDefined(ctrl);
    })
    .forEach(function(controller) {
      var diArray,
          fn;

      if(angular.isArray(controller)) {
        fn = controller.pop();
        diArray = controller;
      } else if(angular.isArray(controller.$inject)) {
        fn = controller;
        diArray = controller.$inject;
      } else {
        throw new TypeError('composeControllers: Controllers being composed must either have dependencies defined in the array style or via $inject');
      }

      functions.push(fn);
      argumentMappings.push(diArray.map(function(dependency) {
        var dependencyIndex = combinedDependencies.indexOf(dependency);

        if(dependencyIndex === -1) {
          combinedDependencies.push(dependency);
          dependencyIndex = combinedDependencies.length - 1;
        }

        return dependencyIndex;
      }));
    });

  function composedController() {
    var _this = this,
        args  = Array.prototype.slice.call(arguments);

    functions.forEach(function(fn, idx) {
      fn.apply(_this, argumentMappings[idx].map(function(val) {
        return args[val];
      }));
    });
  }

  combinedDependencies.push(composedController);

  return combinedDependencies;
}

module.exports = compose;