How to add password validation using regular expre

Question

I want to validate password entered by user for following criteria :

Password should be at least 8 characters long and should contain one number,one character and one special character.

For it I used following regular expression :

^(?=.*[A-Za-z])(?=.*\d)(?=.*[$@$!%*#?&])[A-Za-z\d$@$!%*#?&]{8,}$

I tried this expression in my angularjs code as below :

<md-input-container class="md-block" style="margin-top:0px;">
            <label>Password</label> <md-icon
                md-svg-src="/images/icons/ic_lock_black_24px.svg" class="name"></md-icon>
            <input type="password" ng-model="newUser.userPassword"
                name="userPassword" required 
                ng-pattern="^(?=.*[A-Za-z])(?=.*\d)(?=.*[$@$!%*#?&])[A-Za-z\d$@$!%*#?&]{8,}$">
            <div
                ng-messages="registerForm.userPassword.$error">
                <div ng-message="pattern">Password should be atleast 8 characters long
                    and should contain one number,one character and one special
                    character</div>
                <div ng-message="required">Password should be atleast 8 characters
                    long and should contain one number,one character and one special
                    character</div>
            </div>
            </md-input-container>

In my above code the error message displays when the password field is blank and focus is lost. If user enters a password which doesn't satisfy the criteria I mentioned the error message doesn't show up.

How should I fix this issue? Somebody please help me.

Answer 1

As far as i understood your problem. Check your console It might be broken on lexical errors.

You forgot slash at start and at end of ng-pattern. Please use ng-pattern="/^(?=.*[A-Za-z])(?=.*\d)(?=.*[$@$!%*#?&])[A-Za-z\d$@$!%*#?&]{8,}$/"

I have created a plunk which might help you. https://plnkr.co/edit/qCjp6a?p=preview

Answer 2

Just a couple notes

1) The above contains one redundant $. It should be ng-pattern="/^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$/"

2) Don't remove leading ^ and trailing $ as it prevents from entering white spaces

3) If you want to define the pattern in controller then

$scope.passwordStrength = /^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$/; and <input ng-pattern="passwordStrength">

but never

$scope.passwordStrength = "/^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$/";

as the pattern is a RegExp object, not a string.

Hope this will help you save some time.