提问



我正在寻找任何方式来访问指令中的父范围。范围,转换,要求的任何组合,从上面传入变量(或范围本身)等等。我完全愿意向后弯腰,但我想避免一些完全hacky或不可维护的东西。例如,我知道我现在可以通过从preLink参数中获取$scope并迭代它的$sibling范围来找到概念性的父。


我真正想要的是能够$watch在父范围内的表达式。如果我能做到这一点,那么我可以完成我在这里尝试做的事情:
AngularJS - 如何使用变量渲染部分?


重要说明是指令必须可在同一父作用域内重复使用。因此默认行为(范围:false)对我不起作用。我需要每个指令实例有一个单独的范围,然后我需要$watch一个存在于父范围内的变量。


代码示例值1000个单词,因此:


app.directive('watchingMyParentScope', function() {
    return {
        require: /* ? */,
        scope: /* ? */,
        transclude: /* ? */,
        controller: /* ? */,
        compile: function(el,attr,trans) {
            // Can I get the $parent from the transclusion function somehow?
            return {
                pre: function($s, $e, $a, parentControl) {
                    // Can I get the $parent from the parent controller?
                    // By setting this.$scope = $scope from within that controller?

                    // Can I get the $parent from the current $scope?

                    // Can I pass the $parent scope in as an attribute and define
                    // it as part of this directive's scope definition?

                    // What don't I understand about how directives work and
                    // how their scope is related to their parent?
                },
                post: function($s, $e, $a, parentControl) {
                    // Has my situation improved by the time the postLink is called?
                }
            }
        }
    };
});

最佳参考


请参阅AngularJS中范围原型/原型继承的细微差别是什么?


总结一下:指令访问其父($parent)范围的方式取决于指令创建的范围类型:



  1. default(scope: false) - 该指令不创建新范围,因此这里没有继承。指令的范围与父/容器的范围相同。在链接函数中,使用第一个参数(通常为scope)。

  2. scope: true - 该指令创建一个新的子作用域,它原型继承自父作用域。在父作用域上定义的属性可用于指令scope(因为原型继承)。只要注意写入原始范围属性 - 这将在指令范围上创建一个新属性(隐藏/隐藏同名的父范围属性)。

  3. scope: { ... } - 该指令创建一个新的隔离/隔离范围。它没有原型继承父作用域。您仍然可以使用$parent访问父作用域,但通常不建议这样做。相反,您应该使用=@&指定使用该指令的同一元素上的附加属性指定指令所需的父作用域属性(和/或函数)。]]表示法。

  4. transclude: true - 该指令创建一个新的transcluded子作用域,它原型继承自父作用域。如果该指令还创建了隔离范围,则transcluded和隔离范围是兄弟。每个作用域的$parent属性引用相同的父作用域。
    Angular v1.3 update :如果该指令还创建了一个隔离作用域,则被转换的作用域现在是隔离范围。被抄袭和隔离的范围不再是兄弟姐妹。现在,transcluded范围的$parent属性引用了隔离范围。



以上链接包含所有4种类型的示例和图片。


你不能在指令的编译函数中访问作用域(如下所述:https://github.com/angular/angular.js/wiki/Understanding-Directives)。你可以在链接函数中访问指令的作用域[78]


观赏:


对于1.和2.上面:通常你通过属性指定指令需要哪个父属性,然后$ watch it:





<div my-dir attr1="prop1"></div>





scope.$watch(attrs.attr1, function() { ... });


如果您正在观看对象属性,则需要使用$ parse:


<div my-dir attr2="obj.prop2"></div>





var model = $parse(attrs.attr2);
scope.$watch(model, function() { ... });


对于3. above(隔离范围),使用@=表示法观察您给出指令属性的名称:


<div my-dir attr3="{{prop3}}" attr4="obj.prop4"></div>





scope: {
  localName3: '@attr3',
  attr4:      '='  // here, using the same name as the attribute
},
link: function(scope, element, attrs) {
   scope.$watch('localName3', function() { ... });
   scope.$watch('attr4',      function() { ... });

其它参考1


访问控制器方法意味着从指令控制器/链接/范围访问父作用域上的方法。


如果指令是共享/继承父作用域,则只需调用父作用域方法就可以了。


如果要从Isolated指令范围访问父作用域方法,则需要做更多的工作。


从隔离指令范围调用父作用域方法或观察父作用域变量(选项#6 ),几乎没有选项(可能比下面列出的更多)。


注意我在这些示例中使用了link function,但您也可以根据需要使用directive controller


选项#1。 通过Object文字和指令html模板


index.html


<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.3.x" src="https://code.angularjs.org/1.3.9/angular.js" data-semver="1.3.9"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>Hello {{name}}!</p>

    <p> Directive Content</p>
    <sd-items-filter selected-items="selectedItems" selected-items-changed="selectedItemsChanged(selectedItems)" items="items"> </sd-items-filter>


    <P style="color:red">Selected Items (in parent controller) set to: {{selectedItemsReturnedFromDirective}} </p>

  </body>

</html>


itemfilterTemplate.html


<select ng-model="selectedItems" multiple="multiple" style="height: 200px; width: 250px;" ng-change="selectedItemsChanged({selectedItems:selectedItems})" ng-options="item.id as item.name group by item.model for item in items | orderBy:'name'">
  <option>--</option>
</select>


app.js


var app = angular.module('plunker', []);

app.directive('sdItemsFilter', function() {
  return {
    restrict: 'E',
    scope: {
      items: '=',
      selectedItems: '=',
      selectedItemsChanged: '&'
    },
    templateUrl: "itemfilterTemplate.html"
  }
})

app.controller('MainCtrl', function($scope) {
  $scope.name = 'TARS';

  $scope.selectedItems = ["allItems"];

  $scope.selectedItemsChanged = function(selectedItems1) {
    $scope.selectedItemsReturnedFromDirective = selectedItems1;
  }

  $scope.items = [{
    "id": "allItems",
    "name": "All Items",
    "order": 0
  }, {
    "id": "CaseItem",
    "name": "Case Item",
    "model": "PredefinedModel"
  }, {
    "id": "Application",
    "name": "Application",
    "model": "Bank"
    }]

});


工作plnkr:http://plnkr.co/edit/rgKUsYGDo9O3tewL6xgr?p =preview [79]


选项#2。通过Object文字和指令链接/范围


index.html


<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.3.x" src="https://code.angularjs.org/1.3.9/angular.js" data-semver="1.3.9"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>Hello {{name}}!</p>

    <p> Directive Content</p>
    <sd-items-filter selected-items="selectedItems" selected-items-changed="selectedItemsChanged(selectedItems)" items="items"> </sd-items-filter>


    <P style="color:red">Selected Items (in parent controller) set to: {{selectedItemsReturnedFromDirective}} </p>

  </body>

</html>


itemfilterTemplate.html


<select ng-model="selectedItems" multiple="multiple" style="height: 200px; width: 250px;" 
 ng-change="selectedItemsChangedDir()" ng-options="item.id as item.name group by item.model for item in items | orderBy:'name'">
  <option>--</option>
</select>


app.js


var app = angular.module('plunker', []);

app.directive('sdItemsFilter', function() {
  return {
    restrict: 'E',
    scope: {
      items: '=',
      selectedItems: '=',
      selectedItemsChanged: '&'
    },
    templateUrl: "itemfilterTemplate.html",
    link: function (scope, element, attrs){
      scope.selectedItemsChangedDir = function(){
        scope.selectedItemsChanged({selectedItems:scope.selectedItems});  
      }
    }
  }
})

app.controller('MainCtrl', function($scope) {
  $scope.name = 'TARS';

  $scope.selectedItems = ["allItems"];

  $scope.selectedItemsChanged = function(selectedItems1) {
    $scope.selectedItemsReturnedFromDirective = selectedItems1;
  }

  $scope.items = [{
    "id": "allItems",
    "name": "All Items",
    "order": 0
  }, {
    "id": "CaseItem",
    "name": "Case Item",
    "model": "PredefinedModel"
  }, {
    "id": "Application",
    "name": "Application",
    "model": "Bank"
    }]
});


work plnkr:http://plnkr.co/edit/BRvYm2SpSpBK9uxNIcTa?p=preview [80]


选项#3。通过函数参考和指令html模板


index.html


<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.3.x" src="https://code.angularjs.org/1.3.9/angular.js" data-semver="1.3.9"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>Hello {{name}}!</p>

    <p> Directive Content</p>
    <sd-items-filter selected-items="selectedItems" selected-items-changed="selectedItemsChanged" items="items"> </sd-items-filter>


    <P style="color:red">Selected Items (in parent controller) set to: {{selectedItemsReturnFromDirective}} </p>

  </body>

</html>


itemfilterTemplate.html


<select ng-model="selectedItems" multiple="multiple" style="height: 200px; width: 250px;" 
 ng-change="selectedItemsChanged()(selectedItems)" ng-options="item.id as item.name group by item.model for item in items | orderBy:'name'">
  <option>--</option>
</select>


app.js


var app = angular.module('plunker', []);

app.directive('sdItemsFilter', function() {
  return {
    restrict: 'E',
    scope: {
      items: '=',
      selectedItems:'=',
      selectedItemsChanged: '&'
    },
    templateUrl: "itemfilterTemplate.html"
  }
})

app.controller('MainCtrl', function($scope) {
  $scope.name = 'TARS';

  $scope.selectedItems = ["allItems"];

  $scope.selectedItemsChanged = function(selectedItems1) {
    $scope.selectedItemsReturnFromDirective = selectedItems1;
  }

  $scope.items = [{
    "id": "allItems",
    "name": "All Items",
    "order": 0
  }, {
    "id": "CaseItem",
    "name": "Case Item",
    "model": "PredefinedModel"
  }, {
    "id": "Application",
    "name": "Application",
    "model": "Bank"
    }]
});


工作plnkr:http://plnkr.co/edit/Jo6FcYfVXCCg3vH42BIz?p =preview [81]


选项#4。通过函数参考和指令链接/范围


index.html


<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.3.x" src="https://code.angularjs.org/1.3.9/angular.js" data-semver="1.3.9"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>Hello {{name}}!</p>

    <p> Directive Content</p>
    <sd-items-filter selected-items="selectedItems" selected-items-changed="selectedItemsChanged" items="items"> </sd-items-filter>


    <P style="color:red">Selected Items (in parent controller) set to: {{selectedItemsReturnedFromDirective}} </p>

  </body>

</html>


itemfilterTemplate.html


<select ng-model="selectedItems" multiple="multiple" style="height: 200px; width: 250px;" ng-change="selectedItemsChangedDir()" ng-options="item.id as item.name group by item.model for item in items | orderBy:'name'">
  <option>--</option>
</select>


app.js


var app = angular.module('plunker', []);

app.directive('sdItemsFilter', function() {
  return {
    restrict: 'E',
    scope: {
      items: '=',
      selectedItems: '=',
      selectedItemsChanged: '&'
    },
    templateUrl: "itemfilterTemplate.html",
    link: function (scope, element, attrs){
      scope.selectedItemsChangedDir = function(){
        scope.selectedItemsChanged()(scope.selectedItems);  
      }
    }
  }
})

app.controller('MainCtrl', function($scope) {
  $scope.name = 'TARS';

  $scope.selectedItems = ["allItems"];

  $scope.selectedItemsChanged = function(selectedItems1) {
    $scope.selectedItemsReturnedFromDirective = selectedItems1;
  }

  $scope.items = [{
    "id": "allItems",
    "name": "All Items",
    "order": 0
  }, {
    "id": "CaseItem",
    "name": "Case Item",
    "model": "PredefinedModel"
  }, {
    "id": "Application",
    "name": "Application",
    "model": "Bank"
    }]

});


工作plnkr:http://plnkr.co/edit/BSqx2J1yCY86IJwAnQF1?p =preview [82]


选项#5:通过ng-model和双向绑定,您可以更新父范围变量。。因此,在某些情况下,您可能不需要调用父作用域函数。


index.html


<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.3.x" src="https://code.angularjs.org/1.3.9/angular.js" data-semver="1.3.9"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>Hello {{name}}!</p>

    <p> Directive Content</p>
    <sd-items-filter ng-model="selectedItems" selected-items-changed="selectedItemsChanged" items="items"> </sd-items-filter>


    <P style="color:red">Selected Items (in parent controller) set to: {{selectedItems}} </p>

  </body>

</html>


itemfilterTemplate.html


<select ng-model="selectedItems" multiple="multiple" style="height: 200px; width: 250px;" 
 ng-options="item.id as item.name group by item.model for item in items | orderBy:'name'">
  <option>--</option>
</select>


app.js


var app = angular.module('plunker', []);

app.directive('sdItemsFilter', function() {
  return {
    restrict: 'E',
    scope: {
      items: '=',
      selectedItems: '=ngModel'
    },
    templateUrl: "itemfilterTemplate.html"
  }
})

app.controller('MainCtrl', function($scope) {
  $scope.name = 'TARS';

  $scope.selectedItems = ["allItems"];

  $scope.items = [{
    "id": "allItems",
    "name": "All Items",
    "order": 0
  }, {
    "id": "CaseItem",
    "name": "Case Item",
    "model": "PredefinedModel"
  }, {
    "id": "Application",
    "name": "Application",
    "model": "Bank"
    }]
});


工作plnkr:http://plnkr.co/edit/hNui3xgzdTnfcdzljihY?p=preview[83]


选项#6:通过$watch$watchCollection
在上述所有示例中,它是items的双向绑定,如果在父作用域中修改了项目,则指令中的项目也会反映这些更改。


如果要从父作用域中观察其他属性或对象,可以使用$watch$watchCollection执行此操作,如下所示


HTML


<!DOCTYPE html>
<html ng-app="plunker">

<head>
  <meta charset="utf-8" />
  <title>AngularJS Plunker</title>
  <script>
    document.write('<base href="' + document.location + '" />');
  </script>
  <link rel="stylesheet" href="style.css" />
  <script data-require="angular.js@1.3.x" src="https://code.angularjs.org/1.3.9/angular.js" data-semver="1.3.9"></script>
  <script src="app.js"></script>
</head>

<body ng-controller="MainCtrl">
  <p>Hello {{user}}!</p>
  <p>directive is watching name and current item</p>
  <table>
    <tr>
      <td>Id:</td>
      <td>
        <input type="text" ng-model="id" />
      </td>
    </tr>
    <tr>
      <td>Name:</td>
      <td>
        <input type="text" ng-model="name" />
      </td>
    </tr>
    <tr>
      <td>Model:</td>
      <td>
        <input type="text" ng-model="model" />
      </td>
    </tr>
  </table>

  <button style="margin-left:50px" type="buttun" ng-click="addItem()">Add Item</button>

  <p>Directive Contents</p>
  <sd-items-filter ng-model="selectedItems" current-item="currentItem" name="{{name}}" selected-items-changed="selectedItemsChanged" items="items"></sd-items-filter>

  <P style="color:red">Selected Items (in parent controller) set to: {{selectedItems}}</p>
</body>

</html>


脚本app.js


var app=angular.module(plunker,[[]]);


app.directive('sdItemsFilter', function() {
  return {
    restrict: 'E',
    scope: {
      name: '@',
      currentItem: '=',
      items: '=',
      selectedItems: '=ngModel'
    },
    template: '<select ng-model="selectedItems" multiple="multiple" style="height: 140px; width: 250px;"' +
      'ng-options="item.id as item.name group by item.model for item in items | orderBy:\'name\'">' +
      '<option>--</option> </select>',
    link: function(scope, element, attrs) {
      scope.$watchCollection('currentItem', function() {
        console.log(JSON.stringify(scope.currentItem));
      });
      scope.$watch('name', function() {
        console.log(JSON.stringify(scope.name));
      });
    }
  }
})

 app.controller('MainCtrl', function($scope) {
  $scope.user = 'World';

  $scope.addItem = function() {
    $scope.items.push({
      id: $scope.id,
      name: $scope.name,
      model: $scope.model
    });
    $scope.currentItem = {};
    $scope.currentItem.id = $scope.id;
    $scope.currentItem.name = $scope.name;
    $scope.currentItem.model = $scope.model;
  }

  $scope.selectedItems = ["allItems"];

  $scope.items = [{
    "id": "allItems",
    "name": "All Items",
    "order": 0
  }, {
    "id": "CaseItem",
    "name": "Case Item",
    "model": "PredefinedModel"
  }, {
    "id": "Application",
    "name": "Application",
    "model": "Bank"
  }]
});


您可以随时参考AngularJs文档,以获取有关指令的详细说明。

其它参考2


 scope: false
 transclude: false


你将拥有相同的范围(与父元素)


$scope.$watch(...


根据这两个选项的范围,有很多方法可以访问父作用域。 transclude。

其它参考3


这是我曾经使用过的一个技巧:创建一个虚拟指令来保存父范围并将其放在所需指令之外的某处。例如:


module.directive('myDirectiveContainer', function () {
    return {
        controller: function ($scope) {
            this.scope = $scope;
        }
    };
});

module.directive('myDirective', function () {
    return {
        require: '^myDirectiveContainer',
        link: function (scope, element, attrs, containerController) {
            // use containerController.scope here...
        }
    };
});


接着


<div my-directive-container="">
    <div my-directive="">
    </div>
</div>


也许不是最优雅的解决方案,但它完成了工作。

其它参考4


如果您使用的是ES6 Classes和ControllerAs语法,则需要做一些稍微不同的事情。


请参阅下面的代码段并注意vm是父HTML中使用的父控制器的ControllerAs


myApp.directive('name', function() {
  return {
    // no scope definition
    link : function(scope, element, attrs, ngModel) {

        scope.vm.func(...)

其它参考5


尝试了一切后,我终于找到了解决方案。


只需将以下内容放入模板中:


{{currentDirective.attr = parentDirective.attr; ''}}


它只是写入您要访问当前范围的父范围属性/变量。


还要注意语句末尾的; '',确保模板中没有输出。 (Angular评估每个语句,但只输出最后一个语句。)


它有点笨拙,但经过几个小时的反复试验,它完成了这项工作。