为什么在angularjs中找不到所需指令的控制器？

Question

我在angularjs中写了两个指令，一个嵌入另一个。

以下是指令的脚本：

module.directive('foo', [
   '$log', function($log) {
     return {
      restrict: 'E',
      replace: true,
      transclude: true,
      template: '<div id="test" ng-transclude></div>',
      controller: function($scope) {
        this.scope = $scope;
        return $scope.panes = [];
      },
      link: function(scope, element, attrs) {
        return $log.log('test1', scope.panes);
      }
    };
  }
]);

module.directive('bar', [
  '$log', function($log) {
    return {
      restrict: 'E',
      replace: true,
      transclude: true,
      require: '^?foo',
      controller: function($scope) {
        return this.x = 1;
      },
      template: '<div ng-transclude></div>',
      link: function(scope, element, attrs, fooCtrl) {
        return $log.log('test2', fooCtrl);
      }
    };
  }
]);

下面是一段html：

<foo ng-controller="IndexController">
      <bar></bar>
    </foo>

下面是生成的元素，通过 chrome 开发者工具检查

<div id="test" ng-transclude="" ng-controller="IndexController" class="ng-scope">
      <div ng-transclude="" class="ng-scope"></div>
    </div>

下面是 chrome 控制台输出：

test2 
Array[0]
length: 0
__proto__: Array[0]
 angular.js:5930
test1 
Array[0]
length: 0
__proto__: Array[0]  

问题： 子指令无法获取父指令的控制器，因此“bar”链接函数的第四个参数“fooCtrl”是一个空数组。我做错了什么？

更新和回答：

我终于找到了导致奇怪结果的原因。这只是我犯的一个愚蠢的错误：

 // in directive "foo"
 controller: function($scope) {
    this.scope = $scope;
    // This line below is wrong. It is here 
    // because I transcompiled coffeescript to js.
    // return $scope.panes = [];
    // It should be like below:
    $scope.panes = []
    // I should have written .coffee like below
    // controller: ($scope) ->
    //     @scope = $scope
    //     $scope.panes = []
    //     return # prevent coffeescript returning the above expressions.
    //     # I should rather have added the above line
  }

纠正错误后，我尝试了，发现没有什么可以阻止使用控制器或在子指令中提供空内容。

Answer 1

AFAIK，子指令中不能有控制器。

演示：http://plnkr.co/edit/kv9udk4eB5B2y8SBLGQd?p=preview

app.directive('foo', [
   '$log', function($log) {
     return {
      restrict: 'E',
      replace: true,
      transclude: true,
      template: '<div id="test" ng-transclude></div>',
      controller: function($scope) {
        $scope.panes = ['Item1','Item2','Item3'] 
        return { 
          getPanes: function() { return $scope.panes; }
        };
      },
      link: function(scope, element, attrs, ctrl) {
        $log.log('test1', ctrl, ctrl.getPanes(), scope.panes);  
      }
    };
  }
]);

我删除了子控制器。

app.directive('bar', [
  '$log', function($log) {
    return {
      restrict: 'E',
      replace: true,
      transclude: true,
      require: '^?foo',
      template: '<div ng-transclude></div>',
      link: function(scope, element, attrs, ctrl) {
        scope.x = 1;
        $log.log('test2', ctrl, ctrl.getPanes(), scope.panes, scope.x);
      }
    };
  }
]);