jQuery find() method not working in AngularJS directive

问题

I am having trouble with angularjs directives finding child DOM elements with the injected angular element.

For example I have a directive like so:

myApp.directive('test', function () {
    return {
        restrict: "A",
        link: function (scope, elm, attr) {
            var look = elm.find('#findme');
             elm.addClass("addedClass");
            console.log(look);
        }
    };
});

and HTML such as :

<div ng-app="myApp">
    <div test>TEST Div
        <div id="findme"></div>
    </div>
</div>

I have access to the element which is proffed by adding a class to it. However attempting to access a child element produces an empty array in the var look.

JSFiddle demo is here.

Why is something so trivial not working properly?

回答1:

From the docs on angular.element:

find() - Limited to lookups by tag name

So if you're not using jQuery with Angular, but relying upon its jqlite implementation, you can't do elm.find('#someid').

You do have access to children(), contents(), and data() implementations, so you can usually find a way around it.

回答2:

You can easily solve that in 2 steps:

1- Reach the child element using querySelector like that: var target = element[0].querySelector('tbody tr:first-child td')

2- Transform it to an angular.element object again by doing: var targetElement = angular.element(target)

You will then have access to all expected methods on the targetElement variable.

回答3:

Before the days of jQuery you would use:

   document.getElementById('findmebyid');

If this one line will save you an entire jQuery library, it might be worth while using it instead.

For those concerned about performance: Beginning your selector with an ID is always best as it uses native function document.getElementById.

// Fast:
$( "#container div.robotarm" );

// Super-fast:
$( "#container" ).find( "div.robotarm" );

http://learn.jquery.com/performance/optimize-selectors/

jsPerf http://jsperf.com/jquery-selector-benchmark/32

回答4:

find() - Limited to lookups by tag name you can see more information https://docs.angularjs.org/api/ng/function/angular.element

Also you can access by name or id or call please following example:

angular.element(document.querySelector('#txtName')).attr('class', 'error');

回答5:

I used

elm.children('.class-name-or-whatever')

to get children of the current element

回答6:

If anyone is looking to grab the scope off of a 'controller as' element,.. something like this:

<div id="firstctrl" ng-controller="firstCtrl as vm">

use the following:

var vm = angular.element(document.querySelector('#firstctrl')).scope().vm;

回答7:

You can do it like this:

 var myApp = angular.module('myApp', [])
  .controller('Ctrl', ['$scope', function($scope) {
     $scope.aaa = 3432
 }])
 .directive('test', function () {
    return {
       link: function (scope, elm, attr) {
           var look = elm.children('#findme').addClass("addedclass");
           console.log(look);
        }
   };
});

<div ng-app="myApp" ng-controller="Ctrl">
   <div test>TEST Div
      <div id="findme">{{aaa}}</div>
   </div>
</div>

http://jsfiddle.net/FZGKA/133/

来源：https://stackoverflow.com/questions/14865965/jquery-find-method-not-working-in-angularjs-directive

标签

javascript

angularjs

angularjs-directive