Dynamic validation using ng-pattern Angularjs

Question

I am trying to do validation on a input based on value selected from a dropdown.

JSFiddle: https://jsfiddle.net/Raj_13290/qqLnqw3f/9/

I am changing the value of ng-pattern in ng-change of dropdown. Validation works fine but when I change dropdown value previously entered values in input is not validating.

For example, If I select currency in dropdown and enter a text 'abc' so it validates but when I change dropdown to text it still show invalid value.

I have tried with higher version of Angular it works fine but for 1.2.23 it doesn't work.

Any solution is appreciated. thanks

May I know, why you wanted to stay with older version `1.2.23`, as newer version has not any problem? — Pankaj Parkar, Mar 24 '16 at 09:35
This is some legacy application which have some dependency of older version @PankajParkar — Manish, Mar 24 '16 at 09:37

score 1 · Answer 1 · answered Mar 24 '16 at 11:29

From looking your problem it loks like not updating your CSS class based on the ng-pattern. Not gone into detail but this plunkr might help you.

https://plnkr.co/edit/JSgH3LZHQysIO71u03yF?p=preview

var myApp = angular.module('myApp', []);
myApp.controller("MyCtrl", function ($scope) {
var tThis = this;
$scope.dataTypeList = [{
        'id' : 1,
        "label" : "Currency"
    }, {
        'id' : 2,
        "label" : "Number"
    }, {
        'id' : 3,
        "label" : "Text"
    }
];
$scope.dataTypeValue;
$scope.textValue
$scope.customPattern = '';
$scope.className = "ng-invalid ng-invalid-pattern"
    $scope.setCustomPattern = function () {
    var dataTypeId = $scope.dataTypeValue.id;
    console.log(dataTypeId + 'llsdkfalskdf');
    if (dataTypeId === 1) {
        $scope.customPattern = /^\d{1,10}$/;
    } else if (dataTypeId === 2) {
        $scope.customPattern = /^\d+$/;
    } else if (dataTypeId === 3) {
        $scope.customPattern = /^.*$/;
    }
    return $scope.customPattern
};
$scope.$watch("[dataTypeValue, textValue]", function (nw, old) {
    var s = $('input[name=input]').val()
        $scope.textValue = s;
    var pattern = $scope.setCustomPattern()
        if (pattern.test($scope.textValue)) {
            $scope.className = "ng-valid ng-valid-pattern"
        } else {
            $scope.className = "ng-invalid ng-invalid-pattern"
        }
});

});

thanks Arun, nice finding!! It is a good solution but I can't use $watch because I have many input fields. — Manish, Mar 24 '16 at 18:55

Stepan Kasyanenko · Accepted Answer · 2016-03-25T11:57:42.237

It seems that this is a bug angular.

I found a solution, but it is not very good.

Live example on jsfiddle.

var myApp = angular.module('myApp', []);

myApp.controller("MyCtrl", function($scope) {
  var tThis = this;
  $scope.dataTypeList = [{
    'id': 1,
    "label": "Currency"
  }, {
    'id': 2,
    "label": "Number"
  }, {
    'id': 3,
    "label": "Text"
  }];
  $scope.dataTypeValue;
  $scope.textValue = {
    text: ""
  };
  $scope.customPattern = /.*/;
  $scope.getCustomPattern = function(pInput) {
    if (!$scope.dataTypeValue)
      return $scope.customPattern;
    var dataTypeId = $scope.dataTypeValue.id;
    if (dataTypeId === 1) {
      $scope.customPattern = /^\d{1,10}$/;
    } else if (dataTypeId === 2) {
      $scope.customPattern = /^\d+$/;
    } else if (dataTypeId === 3) {
      $scope.customPattern = /^.*$/;
    }
    if (!$scope.getCustomPattern.isParser) {
      $scope.getCustomPattern.isParser = true;
      pInput.$setViewValue(pInput.$viewValue);
    } else {
      $scope.getCustomPattern.isParser = false;
    }
    return $scope.customPattern;
  };
});

input.ng-invalid {
  border-color: red;
}

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="myApp">
  <div ng-controller="MyCtrl">
    <ng-form name="MyForm">

      <h3>
     With dynamic pattern
    </h3>
      <select ng-model="dataTypeValue" ng-options="t as t.label for t in dataTypeList" ng-change="getCustomPattern(MyForm.input)">

      </select>

      <input type="text" ng-model="textValue.text" ng-pattern="getCustomPattern(MyForm.input)" ng-model-options="{allowInvalid:true}" name="input">
      <br>
      <br>
      <br>Data type: {{dataTypeValue}}
      <br>Entered value: {{textValue}}

    </ng-form>
  </div>
</div>

Thanks Stepan, good work!!! It worked. The local variable 'isParser' was not required. — Manish, Mar 24 '16 at 18:52
@Manish without local variable `isParser` i have recursive execution of function `getCustomPattern`. See this [jsfiddle](https://jsfiddle.net/Stepan_Kasyanenko/bcc256m4/4/). — Stepan Kasyanenko, Mar 25 '16 at 04:11
This doesn't work without `isParser` check. I was referring `var isParser = false ` line. — Manish, Mar 25 '16 at 11:41

Dynamic validation using ng-pattern Angularjs

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