AngularJs 指令 - 如何从指令中获取属性值

Question

知道如何从指令内部访问属性值吗？

    angular.module('portal.directives', [])
        .directive('languageFlag', ['$routeParams', function(params) {
            return function(scope, element, attrs) {
                console.log(attrs["data-key"]); // returns undefined
                console.log(element.attr('data-key')); // returns {{data-key}}
                angular.element(element).css('border', '1px solid red');
            };
        }]);

html代码是:

<ul>
    <li ng-repeat="lng in flags">
        <a class="lngFlag {{flag.Key}}" data-key="{{flag.Key}}" data-id="{{lng.Id}}" ng-click="changeLangHash({'lng':lng.Id })" language-flag></a>
    </li>
</ul>

谢谢

Answer 1

使用 $observe :

Observing interpolated attributes: Use $observe to observe the value changes of attributes that contain interpolation (e.g. src="{{bar}}"). Not only is this very efficient but it's also the only way to easily get the actual value because during the linking phase the interpolation hasn't been evaluated yet and so the value is at this time set to undefined. -- directives doc

return function(scope, element, attrs) {
    attrs.$observe('key', function(value) {
        console.log('key=', value);
    });
}

正如@FMM 在评论中提到的， data Angular 在规范化属性名称时将其剥离，因此使用 key以上，而不是 dataKey .