将参数传递给具有隔离范围的嵌套指令

Question

我在 MainCtrl 中有一个对象 data。该对象用于将数据传递给指令 first-directive 和 second-directive。在这两种情况下都需要双数据绑定。

对于first-directive，我传递了完整的对象data，但是对于second-directive，我想传递numbers对象（scope.numbers = scope.dataFirst.numbers）。

问题：

当我执行 <div second-directive="dataFirst.numbers"></div> 时，我检查 dataSecond 是否是一个对象，它 returns true.

但是当我执行 <div second-directive="numbers"></div> 并检查 dataSecond 是否是一个对象时，它 returns false.

在这两种情况下，如果我执行 console.log(scope)，则会显示 scope.dataSecond 属性。

问题：

为什么会发生这种情况，将参数传递给指令的正确方法是什么？

编辑： 这个想法是制作可重用的指令，这意味着它们不能依赖于其他指令。

angular.module('app',[])

.controller('MainCtrl', function($scope) {
  $scope.data = {
    numbers: {
      n1: 'one',
      n2: 'two'
    },
    letters: {
      a: 'A',
      b: 'B'
    }
  }
})

.directive('firstDirective', function () {
  return {
    template: '<div class="first-directive">\
      <h2>First Directive</h2>\
      {{dataFirst}}\
      <div second-directive="dataFirst.numbers"></div>\
      <div second-directive="numbers"></div>\
      </div>',
    replace: true,
    restrict: 'A',
    scope: {
      dataFirst: '=firstDirective'
    },
    link: function postLink(scope, element, attrs) {
      console.log('first directive')
      console.log(scope)
      scope.numbers = scope.dataFirst.numbers;
    }
  };
})

.directive('secondDirective', function () {
  return {
    template: '<div class="second-directive">\
      <h2>Second Directive</h2>\
      {{dataSecond}}\
      <div class="is-obj">is an object: {{isObj}}</div>\
      </div>',
    replace: true,
    restrict: 'A',
    scope: {
      dataSecond: '=secondDirective'
    },
    link: function postLink(scope, element, attrs) {
      console.log('second directive');
      console.log(scope)
      
      // <div second-directive="XXXX"></div>
      // if 'numbers' returns undefined
      // if 'dataFirst.numbers' returns the object
      console.log(scope.dataSecond); 
      
      scope.isObj = false;
      
      if(angular.isObject(scope.dataSecond)){
        scope.isObj = true;
      }
    }
  };
});

h2 {
  padding: 0;
  margin: 0;
}

.first-directive {
  background: #98FFDA;
  color: black;
  padding: 10px;
}

.second-directive {
  background: #FFA763;
  color: white;
  padding: 10px;
}

.is-obj {
  background: blue;
}

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

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <h2>MainCtrl</h2>
    {{data}}

    <div first-directive="data">
    </div>

    <div second-directive="data">
    </div>
  </body>

</html>

Answer 1

我的解决方案是让第二个指令从第一个指令继承数据对象属性。

angular.module('app', [])

.controller('MainCtrl', function($scope) {
  $scope.data = {
    numbers: {
      n1: 'one',
      n2: 'two'
    },
    letters: {
      a: 'A',
      b: 'B'
    }
  }
})

.directive('firstDirective', function() {
  return {
    template: '<div class="first-directive">\
      <h2>First Directive</h2>\
      {{dataFirst}}\
      <div second-directive></div>\
      <div second-directive></div>\
      </div>',
    replace: true,
    restrict: 'A',
    scope: {
      dataFirst: '=firstDirective'
    },
    controller: function firstDirectiveController($scope) {
      return $scope;
    },
    link: function postLink(scope, element, attrs) {
      console.log('first directive')
      console.log(scope)
      scope.numbers = scope.dataFirst.numbers;
    }
  };
})

.directive('secondDirective', function() {
  return {
    template: '<div class="second-directive">\
      <h2>Second Directive</h2>\
      {{dataSecond}}\
      <div class="is-obj">is an object: {{isObj}}</div>\
      </div>',
    replace: true,
    require: '^firstDirective',
    link: function postLink(scope, iElement, iAttrs, firstDirectiveController) {
      console.log('second directive');
      console.log(firstDirectiveController.dataFirst.numbers);
      
      scope.dataSecond = firstDirectiveController.dataFirst.numbers;

      scope.isObj = false;

      if (angular.isObject(scope.dataSecond)) {
        scope.isObj = true;
      }
    }
  };
});

h2 {
  padding: 0;
  margin: 0;
}

.first-directive {
  background: #98FFDA;
  color: black;
  padding: 10px;
}

.second-directive {
  background: #FFA763;
  color: white;
  padding: 10px;
}

.is-obj {
  background: blue;
}

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

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
      <link rel="stylesheet" href="style.css">
    <script src="script.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <h2>MainCtrl</h2>
    {{data}}

    <div first-directive="data">
    </div>
  </body>

</html>

Answer 2

我将重复之前其他人所说的话 - firstDirective 的 link 函数是 post-link 函数运行s 在 secondDirective 的 link 函数之后 [=15] =] 尚未分配对象 scope.dataFirst.numbers.

但是，通过 require 将两个指令紧密耦合的解决方案对我来说似乎不是最佳选择。

相反，要确保在 inner/child 指令运行（如本例中的 secondDirective）之前在父级中正确分配范围属性在 firstDirective 中使用 pre-link 函数（而不是 post-link)

link: {
  pre: function prelink(scope){
      console.log('first directive')
      console.log(scope)
      scope.numbers = scope.dataFirst.numbers;
    }
}

Demo

将参数传递给具有隔离范围的嵌套指令

Passing params to nested directives with isolated scope

data-binding

scope

directive

angularjs