为什么在禁用输入字段时评估ng-pattern

Question

Why does angular evaluate a pattern when the input field is disabled. It should behave the same way as it does when the input field is hidden?

Check this fiddle, Fiddle for reference

<div ng-app>
    <div ng-controller="PatternTestCtrl">
        <form name="ngform">
            <label for="phone">Change the text to match the placeholder:</label><br/>
            <div>
                <input type="checkbox" ng-model="checkValue" />
            </div>
             used ng-pattern <input type="text" name="phone" ng-model="phone" ng-pattern="/^\d*$/" ng-disabled="!checkValue" maxlength="12" placeholder="555-555-5555"/>
            <div>Pattern validity : {{ngform.phone.$valid}}</div>
            <br>
            <div>
                used ng-if : <input type="text" name="dummyNum" ng-pattern="/^\d*$/" ng-model="dummyNum" ng-if="checkValue" />
            </div>    
        <div> ng-if input box validity : {{ngform.dummyNum.$valid}}</div>
        </form>
    </div>
</div>

Attached images for reference

Answer 1

ng-if removes the element from the dom, hence the ng-pattern does not get evaluated.

ng-show/ng-hide , just make the element invisible, hence ng-pattern would still get evaluated.

ng-disable and ng-pattern are different directives, why should their functionality be intermixed.

We do in our app actually fire evaluations even on disabled fields. So I really do not see the reason why the two should be intermixed.