How can I execute some javascript when a Required Field Validator attached to a textbox fails client-side validation? What I am trying to do is change the css class of the textbox, to make the textbox's border show red.
I am using webforms and I do have the jquery library available to me.
Here is quick and dirty thing (but it works!)
<form id="form1" runat="server">
<asp:TextBox ID="txtOne" runat="server" />
<asp:RequiredFieldValidator ID="rfv" runat="server"
ControlToValidate="txtOne" Text="SomeText 1" />
<asp:TextBox ID="txtTwo" runat="server" />
<asp:RequiredFieldValidator ID="rfv2" runat="server"
ControlToValidate="txtTwo" Text="SomeText 2" />
<asp:Button ID="btnOne" runat="server" OnClientClick="return BtnClick();"
Text="Click" CausesValidation="true" />
</form>
<script type="text/javascript">
function BtnClick() {
//var v1 = "#<%= rfv.ClientID %>";
//var v2 = "#<%= rfv2.ClientID %>";
var val = Page_ClientValidate();
if (!val) {
var i = 0;
for (; i < Page_Validators.length; i++) {
if (!Page_Validators[i].isvalid) {
$("#" + Page_Validators[i].controltovalidate)
.css("background-color", "red");
}
}
}
return val;
}
</script>
You could use the following script:
<script>
$(function(){
if (typeof ValidatorUpdateDisplay != 'undefined') {
var originalValidatorUpdateDisplay = ValidatorUpdateDisplay;
ValidatorUpdateDisplay = function (val) {
if (!val.isvalid) {
$("#" + val.controltovalidate).css("border", "2px solid red");
}
originalValidatorUpdateDisplay(val);
}
}
});
</script>
This code decorates the original ValidatorUpdateDisplay function responsible for updating the display of your validators, updating the controltovalidate as necessary.
Hope this helps,
I think you would want to use a Custom Validator and then use the ClientValidationFunction... Unless it helpfully adds a css class upon fail.
Some time ago I spend a few hours on it and since then I have been using some custom js magic to accomplish this.
In fact is quite simple and in the way that ASP.NET validation works. The basic idea is add a css class to attach a javascript event on each control you want quick visual feedback.
<script type="text/javascript" language="javascript">
/* Color ASP NET validation */
function validateColor(obj) {
var valid = obj.Validators;
var isValid = true;
for (i in valid)
if (!valid[i].isvalid)
isValid = false;
if (!isValid)
$(obj).addClass('novalid', 1000);
else
$(obj).removeClass('novalid', 1000);
}
$(document).ready(function() {
$(".validateColor").change(function() {validateColor(this);});
});
</script>
For instance, that will be the code to add on an ASP.Net textbox control. Yes, you can put as many as you want and it will only imply add a CssClass value.
<asp:TextBox ID="txtBxEmail" runat="server" CssClass="validateColor" />
What it does is trigger ASP.Net client side validation when there is a change on working control and apply a css class if it's not valid. So to customize visualization you can rely on css.
.novalid {
border: 2px solid #D00000;
}
It's not perfect but almost :) and at least your code won't suffer from extra stuff. And the best, works with all kind of Asp.Net validators, event custom ones.
I haven't seen something like this googling so I wan't to share my trick with you. Hope it helps.
extra stuff on server side:
After some time using this I also add this ".novalid" css class from code behind when need some particular validation on things that perhaps could be only checked on server side this way:
Page.Validate();
if (!requiredFecha.IsValid || !CustomValidateFecha.IsValid)
txtFecha.CssClass = "validateColor novalid";
else
txtFecha.CssClass = "validateColor";
Here is my solution.
Advantages over other solutions:
Disadvantages:
HOW TO USE:
Declare a "control_validation_error" CSS class
function Validation_Load() {
if (typeof (Page_Validators) != "object") {
return;
}
for (var i = 0; i < Page_Validators.length; i++) {
var val = Page_Validators[i];
var control = $("#" + val.controltovalidate);
if (control.length > 0) {
var tagName = control[0].tagName;
if (tagName != "INPUT" && tagName != "TEXTAREA" && tagName != "SELECT") {
// Validate sub controls
}
else {
// Validate the control
control.change(function () {
var validators = this.Validators;
if (typeof (validators) == "object") {
var isvalid = true;
for (var k = 0; k < validators.length; k++) {
var val = validators[k];
if (val.isvalid != true) {
isvalid = false;
break;
}
}
if (isvalid == true) {
// Clear the error
$(this).removeClass("control_validation_error");
}
else {
// Show the error
$(this).addClass("control_validation_error");
}
}
});
}
}
}
}
Alternatively, just iterate through the page controls as follows: (needs a using System.Collections.Generic reference)
const string CSSCLASS = " error";
protected static Control FindControlIterative(Control root, string id)
{
Control ctl = root;
LinkedList<Control> ctls = new LinkedList<Control>();
while ( ctl != null )
{
if ( ctl.ID == id ) return ctl;
foreach ( Control child in ctl.Controls )
{
if ( child.ID == id ) return child;
if ( child.HasControls() ) ctls.AddLast(child);
}
ctl = ctls.First.Value;
ctls.Remove(ctl);
}
return null;
}
protected void Page_PreRender(object sender, EventArgs e)
{
//Add css classes to invalid items
if ( Page.IsPostBack && !Page.IsValid )
{
foreach ( BaseValidator item in Page.Validators )
{
var ctrltoVal = (WebControl)FindControlIterative(Page.Form, item.ControlToValidate);
if ( !item.IsValid ) ctrltoVal.CssClass += " N";
else ctrltoVal.CssClass.Replace(" N", "");
}
}
}
Should work for most cases, and means you dont have to update it when you add validators. Ive added this code into a cstom Pageclass so it runs site wide on any page I have added validators to.
