angular-源码分析之rootScope

$rootScope 到底是啥

出处

在bootstrap函数中会调用injector.invoke，里面用到了rootScope:

injector.invoke(['$rootScope', '$rootElement', '$compile', '$injector',
       function bootstrapApply(scope, element, compile, injector) {
        scope.$apply(function() { //rootScope
          element.data('$injector', injector);
          compile(element)(scope);
        });
      }]
    );

从之前的文章中我们可以知道$rootScope从$rootScopeProvider.$get方法返回的，那么我们就可以看$rootScopeProvider.$get方法返回了什么。

$RootScopeProvider

function Scope() {
   this.$id = nextUid();
   this.$$phase = this.$parent = this.$$watchers =
                  this.$$nextSibling = this.$$prevSibling =
                  this.$$childHead = this.$$childTail = null;
   this.$root = this;
   this.$$destroyed = false;
   this.$$listeners = {};
   this.$$listenerCount = {};
   this.$$watchersCount = 0;
   this.$$isolateBindings = null;
 }

 Scope.prototype = {
   constructor: Scope,
   $new: function(isolate, parent) {

   },
   //$apply方法就是在这定义的
     //expr 可以为function
   $apply: function(expr) {
     try {
              beginPhase('$apply');
              try {
                return this.$eval(expr);
              } finally {
                clearPhase();
              }
            } catch (e) {
              $exceptionHandler(e);
            } finally {
              try {
                $rootScope.$digest();
              } catch (e) {
                $exceptionHandler(e);
                throw e;
              }
            }
   }
   //省略
 };
    //定义了Scope对象
var $rootScope = new Scope();

 //The internal queues. Expose them on the $rootScope for debugging/testing purposes.
 var asyncQueue = $rootScope.$$asyncQueue = [];
 var postDigestQueue = $rootScope.$$postDigestQueue = [];
 var applyAsyncQueue = $rootScope.$$applyAsyncQueue = [];

 var postDigestQueuePosition = 0;

 return $rootScope;