How do I store angular directive in a scope variable?

问题

I am implementing a form builder in AngularJS and need to insert and reorder directives at runtime. Don't even know where to start looking - all examples seem to only demonstrate static tree of directives. Two options to achieve dynamic behaviour are: a) compiling and inserting templates on the fly and b) using huge ng-switch of all possible directives. Both ways are ugly.

Can anyone suggest a better implementation?

Below is JS and html code for how I think formbuilder should look in an ideal world, please help me fill in 3 instances of TODO.

JSFiddle JavaScript:

angular.module('components', [])
  .directive('checkbox', function() {
    return {
      restrict: 'E',
      template: '<div class=f><input type=checkbox>{{name}}</input></div>'
    };
  })
  .directive('textfield', function() {
    return {
      restrict: 'E',
      template: '<div class=f><input type=text placeholder="{{name}}"></input></div>'
    };
  })

function FormBuilder($scope, $locale) {
    $scope.title = 'test form';
    $scope.fields = [];  
    $scope.add_checkbox = function() {
        console.log('adding checkbox');
        var field = null; // TODO: how do I instantiate a directive?
        $scope.fields.push(field);
    };
    $scope.add_textfield = function() {
        console.log('adding textfield');
        var field = null; // TODO: how do I instantiate a directive?
        $scope.fields.push(field);
    };
}

HTML:

<div ng-app=components ng-controller=FormBuilder>
    <button ng:click="add_checkbox()">new checbox</button>
    <button ng:click="add_textfield()">new text field</button>
    <h3>{{ title }}</h3>
    <checkbox></checkbox>

    <textfield></textfield>

    <div ng:repeat="field in fields">
        <!-- TODO field.get_html() - how? -->
    </div>
</div>

回答1:

I think you have a couple ways to do this as you mentioned and since you don't want to do a switch you can create a template file for each directive. ie checkbox.html, textfield.html and put the directive in each one. Then populate your fields array with ['checkbox.html', 'textarea.html'] when you add in your loop you just simply <div ng-include='field'></div>

Here is a demo: http://plnkr.co/edit/w6n6xpng6rP5WJHDlJ3Y?p=preview

You could also create another directive where you pass in the input type and have it inject it into the template. Here is a demo of this which allows you to avoid having to declare templates and letting a directive create them based on the field type:

http://plnkr.co/jhWGuMXZTuSpz8otsVRY

<div ng:repeat="field in fields">
  <master-field type='field'></master-field>
</div>

This master-field directive just compiles a template based on the value of field.

.directive('masterField', function($compile) {
   return {
      restrict: 'E',
      replace:true,
      transclude: true,
      scope:{
         type:'='
      },
      template: '<div></div>',
      controller: function ( $scope, $element, $attrs ) {},
      link: function(scope, element, attrs) {

       element.append( $compile('<' + scope.type+ '/></' +scope.type + '>')(scope) ); 
      }
    };
 })

来源：https://stackoverflow.com/questions/16340236/how-do-i-store-angular-directive-in-a-scope-variable

标签

angularjs

angularjs-directive