详解AngularJS的通信机制

angular.module(['application.services'])
  // define the request notification channel for the pub/sub service
  .factory('requestNotificationChannel', ['$rootScope', function ($rootScope) {
    // private notification messages
    var _EDIT_DATA_ = '_EDIT_DATA_';
    var _DATA_UPDATED_ = '_DATA_UPDATED_';
 
    // publish edit data notification
    var editData = function (item) {
      $rootScope.$broadcast(_EDIT_DATA_, {item: item});
    };
    //subscribe to edit data notification
    var onEditData = function($scope, handler) {
      $scope.$on(_EDIT_DATA_, function(event, args) {
        handler(args.item);
      });
    };
    // publish data changed notification
    var dataUpdated = function () {
      $rootScope.$broadcast(_DATA_UPDATED_);
    };
    // subscribe to data changed notification
    var onDataUpdated = function ($scope, handler) {
      $scope.$on(_DATA_UPDATED_, function (event) {
        handler();
      });
    };
    // return the publicly accessible methods
    return {
      editData: editData,
      onEditData: onEditData,
      dataUpdated: dataUpdated,
      onDataUpdated: onDataUpdated
    };
  }])

  // define the data service that manages the data
  .factory('dataService', ['requestNotificationChannel', function (requestNotificationChannel) {
    // private data
    var hops = [
      { "_id": { "$oid": "50ae677361d118e3646d7d6c"}, "Name": "Admiral", "Origin": "United Kingdom", "Alpha": 14.75, "Amount": 0.0, "Use": "Boil", "Time": 0.0, "Notes": "Bittering hops derived from Wye Challenger. Good high-alpha bittering hops. Use for: Ales Aroma: Primarily for bittering Substitutions: Target, Northdown, Challenger", "Type": "Bittering", "Form": "Pellet", "Beta": 5.6, "HSI": 15.0, "Humulene": 0.0, "Caryophyllene": 0.0, "Cohumulone": 0.0, "Myrcene": 0.0, "Substitutes": ""} ,
      { "_id": { "$oid": "50ae677361d118e3646d7d6d"}, "Name": "Ahtanum", "Origin": "U.S.", "Alpha": 6.0, "Amount": 0.0, "Use": "Boil", "Time": 0.0, "Notes": "Distinctive aromatic hops with moderate bittering power from Washington. Use for: Distinctive aroma Substitutes: N/A", "Type": "Aroma", "Form": "Pellet", "Beta": 5.25, "HSI": 30.0, "Humulene": 0.0, "Caryophyllene": 0.0, "Cohumulone": 0.0, "Myrcene": 0.0, "Substitutes": ""} ,
      { "_id": { "$oid": "50ae677361d118e3646d7d6e"}, "Name": "Amarillo Gold", "Origin": "U.S.", "Alpha": 8.5, "Amount": 0.0, "Use": "Boil", "Time": 0.0, "Notes": "Unknown origin, but character similar to Cascade. Use for: IPAs, Ales Aroma: Citrus, Flowery Substitutions: Cascade, Centennial", "Type": "Aroma", "Form": "Pellet", "Beta": 6.0, "HSI": 25.0, "Humulene": 0.0, "Caryophyllene": 0.0, "Cohumulone": 0.0, "Myrcene": 0.0, "Substitutes": ""} ,
      { "_id": { "$oid": "50ae677361d118e3646d7d6f"}, "Name": "Aquila", "Origin": "U.S.", "Alpha": 6.5, "Amount": 0.0, "Use": "Boil", "Time": 0.0, "Notes": "Aroma hops developed in 1988. Limited use due to high cohumolone.Used for: Aroma hops Substitutes: ClusterNo longer commercially grown.", "Type": "Aroma", "Form": "Pellet", "Beta": 3.0, "HSI": 35.0, "Humulene": 0.0, "Caryophyllene": 0.0, "Cohumulone": 0.0, "Myrcene": 0.0, "Substitutes": ""} ,
      { "_id": { "$oid": "50ae677361d118e3646d7d70"}, "Name": "Auscha (Saaz)", "Origin": "Czech Republic", "Alpha": 3.3, "Amount": 0.0, "Use": "Boil", "Time": 0.0, "Notes": " Use for: Pilsners and Bohemian style lagers Aroma: Delicate, mild, clean, somewhat floral -- Noble hops Substitute: Tettnanger, LublinExamples: Pulsner Urquell", "Type": "Aroma", "Form": "Pellet", "Beta": 3.5, "HSI": 42.0, "Humulene": 0.0, "Caryophyllene": 0.0, "Cohumulone": 0.0, "Myrcene": 0.0, "Substitutes": ""} ,
    ];
    // sends notification that data has been updated
    var saveHop = function(hop) {
      requestNotificationChannel.dataUpdated();
    };
    // removes the item from the array and sends a notification that data has been updated
    var deleteHop = function(hop) {
      for(var i = 0; i < hops.length; i++) {
        if(hops[i]._id.$oid === hop._id.$oid) {
          hops.splice(i, 1);
          requestNotificationChannel.dataUpdated();
          return;
        }
      };
    };
    // internal function to generate a random number guid generation
    var S4 = function() {
      return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
    };
    // generates a guid for adding items to array
    var guid = function () {
     return (S4() + S4() + "-" + S4() + "-4" + S4().substr(0,3) + "-" + S4() + "-" + S4() + S4() + S4()).toLowerCase();
    };
    // function to add a hop to the array and sends a notification that data has been updated
    var addHop = function(hop) {
      hops.id.$oid = guid();
      hops.push(hop);
      requestNotificationChannel.dataUpdated();
    };
    // returns the array of hops
    var getHops = function() {
      return hops;
    };
    // returns a specific hop with the given id
    var getHop = function(id) {
      for(var i = 0; i < hops.length; i++) {
        if(hops[i]._id.$oid === id) {
          return hops[i];
        }
      };
    };
    // return the publicly accessible methods
    return {
      getHops: getHops,
      getHop: getHop,
      saveHop: saveHop,
      deleteHop: deleteHop,
      addHop: addHop
    }
  }]);

  //define the controller for view1
  .controller('view1-controller', ['$scope', 'dataService', 'requestNotificationChannel', function($scope, dataService, requestNotificationChannel) {
    $scope.hops = dataService.getHops();
 
    var onDataUpdatedHandler = function() {
      $scope.hops = dataService.getHops();
    }
 
    requestNotificationChannel.onDataUpdated($scope, onDataUpdatedHandler);
 
    $scope.onEdit = function(hop) {
      requestNotificationChannel.editData(hop);
    }
 
    $scope.onDelete = function(hop) {
      dataService.deleteHop(hop);
    }
  }]);

  //define the controller for view1
  .controller('view2-controller', ['$scope', 'dataService', 'requestNotificationChannel', function($scope, dataService, requestNotificationChannel) {
    $scope.hop = null;
 
    var onEditDataHandler = function(item) {
      $scope.hop = item;
    };
 
    requestNotificationChannel.onEditData($scope, onEditDataHandler);
 
    $scope.onSave = function() {
      dataService.saveHop($scope.hop);
      $scope.hop = null;
    }
 
    $scope.onCancel = function() {
      $scope.hop = null;
    }
  }]);