指令中的Angular可选属性

Question

I have a directive:

angular
  .module('test')
  .directive('multiButton', function () {
    return {
      restrict: 'E',
      replace: true,
      scope: {
        disabled: '@'
      },
      template: '<div class="multi-button"><button ng-disabled={{disabled}}></button></div>'
    });

The disabled scope attribute is optional, but I don't want to have "ng-disabled" stuff in my template when rendered if no disabled attribute was submitted.

Is this possible? And if so how?

Answer 1

You can check if the attribute exists on link, and add the related ( ngDisabled ) attribute if so:

angular.module('myApp',[])
    .directive('multiButton', function () {
        return {
            restrict: 'E',
            replace: true,
            scope: {
                disabled: '@?'
            },
            template: '<div class="multi-button"><button></button></div>',
            link: function(scope, element, attr){
                if(attr.disabled){
                    element.find('button').attr('ng-disabled', attr.disabled);
                }
            }
        }
    });

Demo Fiddle: http://jsfiddle.net/guv11rxq/

Now, as expected, <multi-button disabled="hello"></multi-button> will result in:

<div class="multi-button"><button ng-disabled="hello"></button></div>

But without the optional attribute, <multi-button></multi-button> , it will result in:

<div class="multi-button"><button></button></div>

Answer 2

您可以通过在模板中使用ng-if来做到这一点：

 template: '<div class="multi-button" ng-if="disabled != ''"><button ng-disabled={{disabled}}></button></div><div class="multi-button" ng-if="disabled === ''"><button></button></div>'