How to check all fields are empty in Angularjs

How to check all fields in the submit form ng-submit="submit(field)" is empty in controller.js? They consists of few textboxes and one select field.

I would want an alert box to occur if all fields are empty and select option is not selected, instead of individual validation.

While it's not exactly what you're asking about, may be $pristine is what you want? It's a flag on the form indicating whether the form has ever been edited. If someone typed and then cleared out a field, $pristine would still be false, however.

<form name="myform" ng-submit="doSubmit()" ng-controller="FormController">
    <input ng-model="firstName" name="firstName" />

</form>

Then in your controller

.controller('FormController', function($scope){
    $scope.doSubmit = function(){
        if($scope.myform.$pristine){}
    }
})

Alternatively, you can set all your fields to required="true" and use the $valid flag on the form in the same way as described above.