Are forms really this complicated? Instead of relying on complicated error message handling using ng-if expressions, let's make use of the ngMessages directive. Hopefully by now you have a pretty firm grasp of the ngMessages API, and how it can be used to easily perform form validation. Click here to see the demo application to top. By doing this, the error message for the minlength value will appear until the user reaches the desired number of characters. 
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Let's create a validator that will check to see if our email address is available within our database via a GET API call. We can use it for checking if an email address is available and we can ngmezsages use it for other things like validating the uniqueness of usernames or user ID values.
A true form experience is when each error is specific to each piece of data that is collected in the form. Do we really have to use ngIf over 20 times for a form just to show a handful of messages? To learn more about this, you can check out this SitePoint articleor this Stack Overflow thread. Contents 1 AngularJS 1. If you have any questions, or ngmesszges like to share your opinion on this technique, feel free to reach out to me in the comments. Thank you for taking the time to read the article.
For those who are unfamiliar with ng-patternit is used to ensure an input field matches the regular expression that is passed into the attribute. Now, however, ngMessages provides the ability to display custom error messages without having nbmessages violate the D.
The demo ngmessagess functional to the point that it submits data to the server, but it contains a collection of input controls that render error messages in a reusable manner.
Instead of relying on complicated error message handling using ng-if expressions, let's make use of the ngMessages directive.
Since there is no set way of displaying error messages in forms, there are many inconsistent ways to do this in AngularJS. The template gets too heavy and too much if this and if that logic is put into the HTML code.
How can we reuse a template of messages in other parts of ngmesssges application?
Additionally, the error message defined for maxlength will appear once the user surpasses the set number of characters passed into the ng-maxlength attribute. Our validator is nice and reusable. Can we just place the same directive back inside of the ng-messages container? Let's explore a different approach. I will add a required attribute to all of the fields as they will be compulsoryas well as using an ng-model directive to bind them to properties on the current scope.
If ngmessgaes then the next ng-message directive will be examined in this case the email message ngmexsages then that will be displayed if the error exists.
How to use ngMessages in AngularJS
Let's add back our required message and not use the one defined in the template. This feature is not available in 1.
Ngmeseages order of the messages is still the same with the required message showing up firstbut instead of having the general, robot-like required message show up, the message defined within the ng-messages directive will be used instead.
Required Fields The first thing you should take note of is that the form is named exampleForm.
To get around this we may be able to get away with placing the logic inside of a controller The inner ng-message directives add insert and remove themselves which in triggers the enter and leave animation events to kick off.
But now our template code is heavily dependent on the controller and scope. Are forms really this complicated? But we're still relying on an expression that is strictly tied to a particular model on the form. In addition to what we have seen here, there are a bunch of other tricks you can do.
How to use ngMessages in AngularJS -
The real issue with error message management in AngularJS ngmessagew the code required in the template to determine what is displayed. Let's extend our validation scope and add minlength and maxlength validations to our email input element. Click here to learn about animations with ngMessages. But what about if we wanted to display all the messages instead of just one at a time?
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