title: Enable/disable button based on radio button selection in AngularJS
body: <p>I have items in a radio button list (using <code>ng-repeat</code>) with a <code>button</code> (initially disabled with <code>ng-disabled</code>) to continue. When a radio button is selected, I want to enable the "Continue" button.</p>
  
  <p>What's the right way to do this in Angular?</p>
  
  <p>Relevant JS:</p>
  
  <pre><code>$scope.companies = [{
          "id": 3,
          "name": "Twitter"
      }, {
          "id": 2,
          "name": "Google"
      }, {
          "id": 1,
          "name": "Apple"
      }]
  </code></pre>
  
  <p>Relevant HTML:</p>
  
  <pre><code>&lt;table&gt;
    &lt;tr ng-repeat="company in companies"&gt;
       &lt;td&gt;
         &lt;input type="radio" ng-model="companyId" name="companyId" value="{{company.id}}" /&gt;{{company.name}}
        &lt;/td&gt;
    &lt;/tr&gt;
  &lt;/table&gt;
  
  &lt;button ng-disabled="!companyId"&gt;Continue&lt;/button&gt;
  </code></pre>
  
  <p><a href="http://jsfiddle.net/andrewboni/UZkM8/">Jsfiddle</a></p>
  
  <p>Thanks!</p>