Angularjs dynamic ng-pattern validation

Solution 1:

This is an interesting problem, complex Angular validation. The following fiddle implements what you want:

http://jsfiddle.net/2G8gA/1/

Details

I created a new directive, rpattern, that is a mix of Angular's ng-required and the ng-pattern code from input[type=text]. What it does is watch the required attribute of the field and take that into account when validating with regexp, i.e. if not required mark field as valid-pattern.

Notes

Most of the code is from Angular, tailored to the needs of this.
When the checkbox is checked, the field is required.
The field is not hidden when the required checkbox is false.
The regular expression is simplified for the demo (valid is 3 digits).

A dirty (but smaller) solution, if you do not want a new directive, would be something like:

$scope.phoneNumberPattern = (function() {
    var regexp = /^\(?(\d{3})\)?[ .-]?(\d{3})[ .-]?(\d{4})$/;
    return {
        test: function(value) {
            if( $scope.requireTel === false ) {
                return true;
            }
            return regexp.test(value);
        }
    };
})();

And in HTML no changes would be required:

<input type="text" ng-model="..." ng-required="requireTel"
    ng-pattern="phoneNumberPattern" />

This actually tricks angular into calling our test() method, instead of RegExp.test(), that takes the required into account.

Solution 2:

Not taking anything away from Nikos' awesome answer, perhaps you can do this more simply:

<form name="telForm">
  <input name="cb" type='checkbox' data-ng-modal='requireTel'>
  <input name="tel" type="text" ng-model="..." ng-if='requireTel' ng-pattern="phoneNumberPattern" required/>
  <button type="submit" ng-disabled="telForm.$invalid || telForm.$pristine">Submit</button>
</form>

Pay attention to the second input: We can use an ng-if to control rendering and validation in forms. If the requireTel variable is unset, the second input would not only be hidden, but not rendered at all, thus the form will pass validation and the button will become enabled, and you'll get what you need.

Solution 3:

Used pattern :

 ng-pattern="/^\d{0,9}(\.\d{1,9})?$/"

Used reference file:

 '<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.js"></script>'

Example for Input:

 <input type="number" require ng-pattern="/^\d{0,9}(\.\d{1,9})?$/"><input type="submit">