I suggest to use sub-forms. AngularJS supports putting one form inside another, and validity is propagated form lower form to upper;
Here is example: http://plnkr.co/edit/SruBmlGZZtbwiU8cktAp?p=preview
Here is some code so you can grasp the idea:
<form name='myform' ng-init="step = 1">
<div ng-show="step==1">
<h3>Step 1: Enter some general info</h3>
<div ng-form='step1form'>
Name: <input ng-model="name" required>
</div>
<button ng-disabled="!step1form.$valid" ng-click="step = 2">Next</button>
</div>
<div ng-show="step==2">
<h3>Step 2: Final info</h3>
<div ng-form="step2form">
Phone: <input ng-model="phone" required>
</div>
<button ng-click="step = 1">Prev</button>
<button ng-disabled="!myform.$valid" ng-click="submit()">Submit</button>
</div>
<div>
Validation status:
<div> Whole form valid? {{myform.$valid}} </div>
<div> Step1 valid? {{step1form.$valid}} </div>
<div> Step2 valid? {{step2form.$valid}} </div>
</div>
</form>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…