Angularjs ng-class toggle between several classes - angularjs

Question

This might be a simple question to some of you.
<div class="component"
ng-class="{'small': small, 'medium': medium, 'large': large, 'xlarge': xlarge}"
ng-if="component.title == 'Heading'"
ng-init="editing = false; small = false; medium = false; large = false; xlarge = false">
<input class="heading" ng-blur="editing = false" ng-hide="!editing" type="text" placeholder="Heading" ng-model="component.element" />
<h2 ng-click="editing = true" ng-hide="editing">{{component.element}}</h2>
<div ng-hide="!editing" class="textEditor">
<ul>
<li>
<a href="" ng-click="small = true">
<span class="icon-size small"></span>
</a>
</li>
<li>
<a href="" ng-click="medium = true">
<span class="icon-size medium"></span>
</a>
</li>
<li>
<a href="" ng-click="large = true">
<span class="icon-size large"></span>
</a>
</li>
<li>
<a href="" ng-click="xlarge = true">
<span class="icon-size xlarge"></span>
</a>
</li>
</ul>
</div>
</div>
I need to add class to .component based on clicked a tag from Unordered list. I need to add class small to .component if first item is clicked, then if another item is clicked I need to remove small class and add respective class from that A tag.
Currently it adds them classes but not removing the ones that were added previously.
Basically I need to create a sort of toggle between them 4 classes

Answer 1

Try:
ng-class="small ? 'small' : medium ? 'medium' : large: 'large : xlarge ? 'xlarge' : ''"

Answer 2

I'd say use separate variable for it customClass
ng-class="customClass"
Then markup
<ul>
<li>
<a href="" ng-click="customClass = 'small'">
<span class="icon-size small"></span>
</a>
</li>
<li>
<a href="" ng-click="customClass = 'medium'">
<span class="icon-size medium"></span>
</a>
</li>
<li>
<a href="" ng-click="customClass = 'large'">
<span class="icon-size large"></span>
</a>
</li>
<li>
<a href="" ng-click="customClass = 'xlarge'">
<span class="icon-size xlarge"></span>
</a>
</li>
</ul>