AngularJS: disable button when input fields are empty

Question

I have a dropdown menu, two input text box, and a submit button. I want the submit button to be disabled until dropdown item is selected AND both input boxes are filled. I looked at several examples including this one and this one but none of these are working for me. Below is my code. Thanks

<form name="myForm">
  Select an option:
  <select id="dropDown" name="dropDown" ng-model="data.dropDown" >
    ** content for dropDown menu, populating it by using Django
  </select>
  From Date:
  <input type="text" id="dateFrom" ng-model="data.date1" />
  To Date:
  <input type="text" id="dateTo" ng-model="data.date2"   />

  <button id="submit" ng-click="submitRequest()" ng-disabled="!(!!data.dropDown && !!data.date1  && !!data.date2)">Submit </button>
</form>

I also tried this method below:

<form name="myForm">
  Select an option:
  <select id="dropDown" name="dropDown" ng-model="data.dropDown" >
    ** content for dropDown menu, populating it by using Django
  </select>
  From Date:
  <input type="text" id="dateFrom" ng-model="data.date1" required/>
  To Date:
  <input type="text" id="dateTo" ng-model="data.date2" required />
  <button id="submit" ng-click="submitRequest()" ng-disabled="myForm.$invalid">Submit </button>
</form>

So initially when the page loads and all fields are empty by default, the Submit button is disabled and the problem is that after all three fields are filled, it doesn't get enabled. Thanks

Answer 1

Your second method works for me (utilizing myForm.$invalid) if I add required to the dropdown element. I've created a plunkr you can play with here.

<form name="myForm">
  Select an option:
  <select id="dropDown" name="dropDown" ng-model="data.dropDown" required>
    <option>red</option>
    <option>blue</option>
    <option>green</option>
  </select><br/>
  From Date:
  <input type="text" id="dateFrom" ng-model="data.date1" required/><br/>
  To Date:
  <input type="text" id="dateTo" ng-model="data.date2" required /><br/>
  <button id="submit" ng-click="submitRequest()" ng-disabled="myForm.$invalid">Submit</button>
</form>

Note: I used Angular 1.4 in the plunkr as you did not specify which version of Angular you are working with.

Edit: OP stated that issue was created by using JQuery's datepicker. May I suggest using angular-ui boostrap datepicker? Plunker example - Angular-UI Bootstrap docs

Answer 2

Why dont you use ng-disabled="myForm.myName.$pristine" because pristine will check for each variable inserted in textboxes

please check small example here.. ng pristine example