Validating Partial Page with ASP.NET Validators using JavaScript

Validation plays a key role whenever we take inputs from the user. For this, ASP.NET provides us with few validator controls that are used a lot in web applications. Nowadays, in our application, we have several sections in our web pages. And also, we populate some data based on the user’s input. So several times, it is required to validate the page partially not the entire page, while earlier we used to have a single submit button and there we needed to validate the page.

AJAX also played a key role, for partial post back, initiate a call to server, etc., which requires to validate a part of the page.

So, in these scenarios, our earlier approach of validation would not work. In this kind of scenario, I will discuss few things that will be very helpful.

First, I would suggest to divide your page in some logical section, those you might need to validate at certain points. Then, assign a different group name to the validators on those sections.

1. If you are initiating an Ajax call or initiating a callback from JavaScript, and you want to validate certain sections/parts of the page.

   So before initiating the Ajax call, you need to validate the user inputs. This can be easily done with the following method.

   You need to call Page_ClientValidate() method, this method has two flavors:

   • Page_ClientValidate() it fires all the validators on the page and returns false, if it fails
   • Page_ClientValidate(‘groupname’), this method fires all the validators having the passed groupname and returns false if any validator fails

   This is quite useful, while validating partial section/part of the page. So your JavaScript code may look like this:

   function SaveAddress()
   {
       if(Page_ClientValidate('groupname') == false)
           return false;
       else
       {
           //Save Address
       }
   }

2. Several times, it happens that based on some requirement, we used to hide some section of input form or hide some input control, but whenever page/section is going to be submitted, the hidden validators also get fired. So to overcome this problem, you may need to disable the validators. So to disable any validator from JavaScript:

   document.getElementById('ValidatorClientId').enabled=false;

   So this validator wont be fired till you enable it again. You can enable it as:

   document.getElementById('ValidatorClientId').enabled=true;

Hope you like this post and find it useful.