有ng-disable表达式时如何从控制器启用md-button？

Question

I have one md-button in my form and i am setting it with ng-disable expression. everything is working fine. but now I want to enable button on particular condition from controller. I am setting it like this.

vm.verifyMobileForm.$invalid = true;

but this didn't work for me.

this is my element

<form name="verifyMobileForm" novalidate>
    <md-input-container class="md-block" md-no-float>
        <input type="mobile" id="mobile" ng-value="{{vm.form.mobile}}" 
                name="mobile" ng-model="vm.form.mobile" 
                placeholder="Your Mobile number" 
                ng-pattern="/^[789]\d{9}$/" maxlength="10" required
        />
        <div ng-messages="verifyMobileForm.mobile.$error" role="alert" multiple>
            <div ng-message="required">
                <span >Mobile no. is required</span>
            </div>

        </div>

    </md-input-container>
    <div class="dialog-demo-content" layout="row" layout-wrap layout-margin layout-align="center">
        <md-button type="submit" 
              class="md-raised md-accent submit-button" 
              ng-disabled="verifyMobileForm.$invalid || verifyMobileForm.$pristine" 
              ng-click = "vm.checkMobile($event, document.getElementById('mobile').value)"
        >
            Next
        </md-button>
    </div>
</form>

this is my controller where from i want to set it true

(function ()
{
    'use strict';

    angular
        .module('app.pages.auth.verify-mobile')
        .controller('VerifyMobileController', VerifyMobileController);

    /** @ngInject */
    function VerifyMobileController($scope,dataservice,msApi, $state,$mdDialog)
    {
        var vm = this;
        vm.form = {};
        var getMob = dataservice.getData();
        if(getMob){
            vm.form.mobile = getMob[1].mobile;
            vm.verifyMobileForm.$invalid = true;
        }
    }
}();

Answer 1

You say you want to ENABLE the Button on particular condition? So why dont use something like this

ng-disabled="(verifyMobileForm.$invalid || verifyMobileForm.$pristine) && DISABLEBUTTON"

...

and in controller you can enable button even when form is invalid with

$scope.DISABLEBUTTON = false;