How to validate an IP in a text field AngularJS

Question

How to validate an IP in a textfield in AngularJS ? Currently I am using this code, but its not working in all cases . Any idea ?

ng-pattern='/^((([01]?[0-9]{1,2})|(2[0-4][0-9])|(25[0-5]))[.]){3}(([0-1]?[0-9]{1,2})|(2[0-4][0-9])|(25[0-5]))$/

Solution

Use:

/\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/

Matches 0.0.0.0 through 255.255.255.255

If you want to drop 0.0.0.0 and255.255.255.255 I suggest you to add additional if statement. Otherwise the regex will be too complicated.

Example with watcher:

$scope.ip = '1.2.3.4';

    $scope.$watch(function () {
        return $scope.ip;
    },

    function (newVal, oldVal) {            
        if (
            newVal != '0.0.0.0' && newVal != '255.255.255.255' &&
            newVal.match(/\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/))
        {
             // Match attempt succeeded
        } else {
            // Match attempt failed
        }
    })

---

Demo Fiddle

[Edit]

The best bet is to create directive, something like: <ip-input>

This example might helpful how to create directive for custom input: format-input-value-in-angularjs

Comments

[Ronald91]

Instead of adding a watch in your controller you can put this functionality inside an angular function and use that as an expression in the ng-change directive.

[Maxim Shoustin]

@Ronald91 Well, for sure directive way is more appropriate, something like <input-ip>. But SO asks the regex validation. I added watcher only for demo. BTW, this is an example I wrote once with $parsers: stackoverflow.com/questions/19890364/…