How to set an input field to ng-invalid in angular

问题:

I would like to check an input field for credit card numbers.

The field should remain invalid until it has a minimum length of 13. As the user should be able to fill in space into the field, I remove those spaces within a javascript function. In this function I would like to check the credit card number (without spaces) and set it to ng-invalid as long as the minimum length is lesser than 13 and the maximum length is greater than 16.

It should be something like this:

$scope.ccHandler = function() {
   if ($scope.ccNumber == '') {
      document.getElementById("ccProvider").disabled = false;
   }
   $scope.ccNumber = inputCC.value.split(' ').join(''); //entfernt die Leerzeichen aus der Kreditkartennummer vor der übergabe an den Server
   console.log("das ist meine CC: " + $scope.ccNumber);
   isValidCreditCardNumber($scope.ccNumber);
   getCreditCardProvider($scope.ccNumber);
   document.getElementById("ccProvider").disabled = true;
   if ($scope.ccNumber.length < creditCardNumberMinLength || $scope.ccNumber.length > creditCardNumberMaxLength) {
      //$scope.ccNumber.ng-invalid = true;
      console.log("ccNumber ist noch ungültig!");
      //document.getElementById("inputCC").$setValidity("ccNumber", false);
   }
}

This would be the part of the XHTML:

<div class="form-group" ng-switch-when="CreditCard">
   <label class="col-xs-3 col-sm-3 control-label">Kreditkartennummer</label> 
   <div class="col-xs-5 col-sm-5 col-md-5">
      <input name="ccNumber" class="form-control" type="text" id="inputCC" ng-change="ccHandler();updateCount()" ng-model="ccNumber" ng-required="true"/>
   </div>
</div>

How can I achieve this?

回答1:

You can do that with $setValidity. You need to set a name attribute on the <form> for this to work.

<form name="myForm">
   <input name="ccNumber" ng-model="ccNumber">
   <span ng-show="myForm.ccNumber.$error.minLength">
      A cc number should be minimum 10 chars
   </span>
</form>

Then you can manually set the validity with

$scope.myForm.ccNumber.$setValidity("minLength",$scope.ccNumber.length>=10);

Here is a working plnkr: http://plnkr.co/edit/7J326LR194SaoE2TmHuU?p=preview

回答2:

The following code worked for me:

$scope.myForm.ccNumber.$setValidity("ccNumber", false);

回答3:

You can use the standard ng-maxlength and ng-minlength attributes on your input field.

There is a working example in the AngularJS docs.

 <input type="text" name="lastName" ng-model="user.last" 
     ng-minlength="3" ng-maxlength="10">