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AngularJS - 创建使用ng-model的指令

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我正在尝试创建一个指令,该指令将使用与创建指令的元素相同的ng-model创建输入字段 .

这是我到目前为止所提出的:

HTML

<!doctype html>
<html ng-app="plunker" >
<head>
  <meta charset="utf-8">
  <title>AngularJS Plunker</title>
  <link rel="stylesheet" href="style.css">
  <script>document.write("<base href=\"" + document.location + "\" />");</script>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.2/angular.js"></script>
  <script src="app.js"></script>
</head>
<body ng-controller="MainCtrl">
  This scope value <input ng-model="name">
  <my-directive ng-model="name"></my-directive>
</body>
</html>

JavaScript

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

app.controller('MainCtrl', function($scope) {
  $scope.name = "Felipe";
});

app.directive('myDirective', function($compile) {
  return {
    restrict: 'E',
    scope: {
      ngModel: '='
    },
    template: '<div class="some"><label for="{{id}}">{{label}}</label>' +
      '<input id="{{id}}" ng-model="value"></div>',
    replace: true,
    require: 'ngModel',
    link: function($scope, elem, attr, ctrl) {
      $scope.label = attr.ngModel;
      $scope.id = attr.ngModel;
      console.debug(attr.ngModel);
      console.debug($scope.$parent.$eval(attr.ngModel));
      var textField = $('input', elem).
        attr('ng-model', attr.ngModel).
        val($scope.$parent.$eval(attr.ngModel));

      $compile(textField)($scope.$parent);
    }
  };
});

但是,我不相信这是处理这种情况的正确方法,并且有一个错误,我的控件没有使用ng-model目标字段的值进行初始化 .

这是上面代码的Plunker:http://plnkr.co/edit/IvrDbJ

处理这个问题的正确方法是什么?

EDIT :从模板中删除 ng-model="value" 后,这似乎工作正常 . 但是,我会保持这个问题的开放性,因为我想仔细检查这是否是正确的方法 .

8 回答

  • 29

    从Angular 1.5开始,可以使用组件 . 组件是即将推出的方式,可以轻松解决这个问题 .

    <myComponent data-ng-model="$ctrl.result"></myComponent>
    
    app.component("myComponent", {
        templateUrl: "yourTemplate.html",
        controller: YourController,
        bindings: {
            ngModel: "="
        }
    });
    

    在YourController中你需要做的就是:

    this.ngModel = "x"; //$scope.$apply("$ctrl.ngModel"); if needed
    
  • 66

    当您需要访问模型的$ viewValue或$ modelValue时,您只需要ng-model . 见NgModelController . 在这种情况下,你会使用 require: '^ngModel' .

    其余的,请参阅Roys answer .

  • 0

    我对所有答案进行了组合,现在有两种方法可以使用ng-model属性:

    • 使用复制ngModel的新范围

    • 与链接上编译的范围相同

    var app = angular.module('model', []);
    
    app.controller('MainCtrl', function($scope) {
      $scope.name = "Felipe";
      $scope.label = "The Label";
    });
    
    app.directive('myDirectiveWithScope', function() {
      return {
        restrict: 'E',
        scope: {
          ngModel: '=',
        },
        // Notice how label isn't copied
        template: '<div class="some"><label>{{label}}: <input ng-model="ngModel"></label></div>',
        replace: true
      };
    });
    app.directive('myDirectiveWithChildScope', function($compile) {
      return {
        restrict: 'E',
        scope: true,
        // Notice how label is visible in the scope
        template: '<div class="some"><label>{{label}}: <input></label></div>',
        replace: true,
        link: function ($scope, element) {
          // element will be the div which gets the ng-model on the original directive
          var model = element.attr('ng-model');
          $('input',element).attr('ng-model', model);
          return $compile(element)($scope);
        }
      };
    });
    app.directive('myDirectiveWithoutScope', function($compile) {
      return {
        restrict: 'E',
        template: '<div class="some"><label>{{$parent.label}}: <input></label></div>',
        replace: true,
        link: function ($scope, element) {
          // element will be the div which gets the ng-model on the original directive
          var model = element.attr('ng-model');
          return $compile($('input',element).attr('ng-model', model))($scope);
        }
      };
    });
    app.directive('myReplacedDirectiveIsolate', function($compile) {
      return {
        restrict: 'E',
        scope: {},
        template: '<input class="some">',
        replace: true
      };
    });
    app.directive('myReplacedDirectiveChild', function($compile) {
      return {
        restrict: 'E',
        scope: true,
        template: '<input class="some">',
        replace: true
      };
    });
    app.directive('myReplacedDirective', function($compile) {
      return {
        restrict: 'E',
        template: '<input class="some">',
        replace: true
      };
    });
    
    .some {
      border: 1px solid #cacaca;
      padding: 10px;
    }
    
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.0/angular.min.js"></script>
    <div ng-app="model" ng-controller="MainCtrl">
      This scope value <input ng-model="name">, label: "{{label}}"
      <ul>
        <li>With new isolate scope (label from parent):
          <my-directive-with-scope ng-model="name"></my-directive-with-scope>
        </li>
        <li>With new child scope:
          <my-directive-with-child-scope ng-model="name"></my-directive-with-child-scope>
        </li>
        <li>Same scope:
          <my-directive-without-scope ng-model="name"></my-directive-without-scope>
        </li>
        <li>Replaced element, isolate scope:
          <my-replaced-directive-isolate ng-model="name"></my-replaced-directive-isolate>
        </li>
        <li>Replaced element, child scope:
          <my-replaced-directive-child ng-model="name"></my-replaced-directive-child>
        </li>
        <li>Replaced element, same scope:
          <my-replaced-directive ng-model="name"></my-replaced-directive>
        </li>
      </ul>
      <p>Try typing in the child scope ones, they copy the value into the child scope which breaks the link with the parent scope.
      <p>Also notice how removing jQuery makes it so only the new-isolate-scope version works.
      <p>Finally, note that the replace+isolate scope only works in AngularJS >=1.2.0
    </div>
    

    我不确定我喜欢链接时的编译 . 但是,如果您只是将元素替换为另一个元素,则不需要这样做 .

    总而言之,我更喜欢第一个 . 只需将范围设置为 {ngModel:"="} ,并在模板中将 ng-model="ngModel" 设置为您想要的位置 .

    Update :我内联了代码段并为Angular v1.2更新了它 . 事实证明,隔离范围仍然是最好的,特别是在不使用jQuery时 . 所以归结为:

    • 您是否正在替换单个元素:只需替换它,保留范围,但请注意,对于v2.0,不推荐使用replace:
    app.directive('myReplacedDirective', function($compile) {
      return {
        restrict: 'E',
        template: '<input class="some">',
        replace: true
      };
    });
    
    • 否则使用此:
    app.directive('myDirectiveWithScope', function() {
      return {
        restrict: 'E',
        scope: {
          ngModel: '=',
        },
        template: '<div class="some"><input ng-model="ngModel"></div>'
      };
    });
    
  • 0

    它实际上是非常好的逻辑,但你可以简化一些事情 .

    指令

    var app = angular.module('plunker', []);
    
    app.controller('MainCtrl', function($scope) {
      $scope.model = { name: 'World' };
      $scope.name = "Felipe";
    });
    
    app.directive('myDirective', function($compile) {
      return {
        restrict: 'AE', //attribute or element
        scope: {
          myDirectiveVar: '=',
         //bindAttr: '='
        },
        template: '<div class="some">' +
          '<input ng-model="myDirectiveVar"></div>',
        replace: true,
        //require: 'ngModel',
        link: function($scope, elem, attr, ctrl) {
          console.debug($scope);
          //var textField = $('input', elem).attr('ng-model', 'myDirectiveVar');
          // $compile(textField)($scope.$parent);
        }
      };
    });
    

    带指令的Html

    <body ng-controller="MainCtrl">
      This scope value <input ng-model="name">
      <my-directive my-directive-var="name"></my-directive>
    </body>
    

    CSS

    .some {
      border: 1px solid #cacaca;
      padding: 10px;
    }
    

    您可以使用此Plunker查看它的运行情况 .

    这是我看到的:

    • 我明白你为什么要使用'ng-model',但在你的情况下没有必要 . ng-model用于链接现有html元素和范围中的值 . 由于您're creating a directive yourself you'正在创建'new' html元素,因此您不需要ng-model .

    EDIT 正如Mark在他的评论中提到的那样,没有理由不能使用ng-model,只是为了遵守惯例 .

    • 通过在指令中显式创建范围('isolated'范围),父范围上的指令's scope cannot access the ' name'变量(这就是为什么,我想,你想使用ng-model) .

    • 我从您的指令中删除了ngModel,并将其替换为您可以更改为任何内容的自定义名称 .

    • 使这一切仍然有效的是'='在范围内签名 . 查看'scope' Headers 下的文档docs .

    通常,如果希望指令中的值始终映射到父作用域中的值,则指令应使用隔离作用域(您已正确执行)并使用'='类型作用域 .

  • 50

    我不会通过属性设置ngmodel,您可以在模板中正确指定:

    template: '<div class="some"><label>{{label}}</label><input data-ng-model="ngModel"></div>',
    

    plunkerhttp://plnkr.co/edit/9vtmnw?p=preview

  • 206

    它不是那么复杂:在你的dirctive中,使用别名: scope:{alias:'=ngModel'}

    .directive('dateselect', function () {
    return {
        restrict: 'E',
        transclude: true,
        scope:{
            bindModel:'=ngModel'
        },
        template:'<input ng-model="bindModel"/>'
    }
    

    在您的HTML中,正常使用

    <dateselect ng-model="birthday"></dateselect>
    
  • 15

    创建隔离范围是不可取的 . 我会避免使用scope属性并执行类似的操作 . scope:true为您提供一个新的子范围,但不是隔离 . 然后使用parse将本地范围变量指向用户提供给ngModel属性的同一对象 .

    app.directive('myDir', ['$parse', function ($parse) {
        return {
            restrict: 'EA',
            scope: true,
            link: function (scope, elem, attrs) {
                if(!attrs.ngModel) {return;}
                var model = $parse(attrs.ngModel);
                scope.model = model(scope);
            }
        };
    }]);
    
  • 2

    这是一个迟到的答案,但我发现这很棒post关于 NgModelController ,我认为这正是你在寻找的地方 .

    TL;DR - 您可以使用 require: 'ngModel' 然后将 NgModelController 添加到您的链接功能:

    link: function(scope, iElement, iAttrs, ngModelCtrl) {
      //TODO
    }
    

    这样,不需要黑客 - 你正在使用Angular的内置 ng-model

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