angularjs 指令scope 绑定问题(directory scope binding)

都知道directory独立scope有三种映射方式（https://docs.angularjs.org/guide/directive），但当我想在link函数中使用controller（非父指令中的controller）的$scope属性时，总是映射失败，最后查到是向下面这样使用：

Controller:
/* more code */
$scope.someObject = { name:'Umur', id:1 };
/* more code */

HTML:
<my-directive my-attribute="someObject" />  

Directive:
{
  scope: {myValue: "=myAtrribute" },
  link: function (scope, iElm, iAttrs) {
    var x = scope.myValue.name;
    // x == "Umur";
    scope.myValue.name = "Kieslowski";
    // if we go to parent scope (controller's scope, in this example)
    // $scope.someObject.name == "Kieslowski";
    // would be true
  }
}

以上是双向绑定方式，除此之外还有单项绑定和字符串绑定

单项绑定：

Controller:
/* more code */
$scope.someObject = { name:'Umur', id:1 };
/* more code */

HTML:
<my-directive my-attribute="someObject" />

Directive:
{
  scope: {myValue: "&myAttribute"},
  link: function (scope, iElm, iAttrs) {
    var x = scope.myValue();
    // x == {name:"Umur", id:1}
  }
}

text绑定：

JS:
angular.module("myApp", [])  
  .directive("myDirective", function () {
    return {
      restrict: "A",
      scope: {
        text: "@myText"
      }
    };
}).controller("myController", function ($scope) {
  $scope.foo = {name: "Umur"};
  $scope.bar = "qwe";
});

HTML:
<div ng-controller="myController">  
  <div my-directive 
       my-text="hello {{ bar }}" 
  </div>
</div>  
Results:

/* Directive scope */

in: $scope.text  
out: "hello qwe"  
// this would automatically update the changes of value in digest
// this is always string as dom attributes values are always strings

参考文档：

https://umur.io/angularjs-directives-using-isolated-scope-with-attributes/

https://docs.angularjs.org/guide/directive