角度列表项处于活动状态（ng-click）

Question

So i am trying to add / remove a class from a list item all depending on a variable: (Note if there is a better of doing this active thing please let me know :P )

So my code looks like this:

<li ng-repeat="fold in folds" class="{{selectedFolder == fold.filter ?  'active' : ''}}">
    <a ng-click="selectedFolder = fold.filter">
        {{fold.name}}
    </a>
</li>

Now when i click the first one the class is added however once i click the next one the old class is not replaced by '' instead now two li has the class active

Can anyone tell me why?

Answer 1

You can use ng-class

<li ng-repeat="fold in folds" ng-class="{'active' :  selectedFolder == fold.filter}">
    .....
</li>

this will add the css class active to the li element when selectedFolder == fold.filter is sets to true , IF selectedFolder == fold.filter is sets to false then active class is remove from the li element.

if you need to toggle the css class add & remove when clicking, I think you can remove the .. ng-click="selectedFolder = fold.filter"... part and replace it with ng-click="selectedFolder = !selectedFolder" and change the ng-class to ng-class="{'active' : selectedFolder == 1} and add ng-init="selectedFolder = 0" to the li , This will add a variable to ng-repeat scope so that each repeat has its own selectedFolder variable in its scope (ng-repeat creates a child scope) .

when click in <a> we can toggle the value of selectedFolder so that will toggle the css class ..<a ng-click="selectedFolder = !selectedFolder">..

here is the DEMO

UPDATE

to having one active element.

create a variable to refer the active element. (I used object because its easy to refer from the ng-repeat because ng-repeat creates a child scope, so we cant directly call if this variable is just a primitive variable if its primitive we have to use $parent.variable_name ), So its easy to use a object to represent it.

 $scope.active = {
    elm : -1
 }

when click on <a> assign the $index value to active.elm

<a ng-click="active.elm = $index">
..

$index is the ng-repeat index just like

for first repeat $index is equals to 0 for second repeat $index is equals to 1 .. like wise.

change ng-class to, this will add class active when active.elm == $index set to true .

..ng-class="{'active' :  active.elm == $index}">
...

here is the DEMO

Answer 2

use ng-class

<li ng-repeat="fold in folds" ng-class="{{selectedFolder == fold.filter ?  'active' : ''}}">
    <a ng-click="selectedFolder = fold.filter">
        {{fold.name}}
    </a>
</li>