Why doesn't my form post when I disable the submit button to prevent double clicking?

Like every other web developer on the planet, I have an issue with users double clicking the submit button on my forms. My understanding is that the conventional way to handle this issue, is to disable the button immediately after the first click, however when I do this, it doesn't post.

I did do some research on this, god knows there's enough information, but other questions like Disable button on form submission, disabling the button appears to work. The original poster of Disable button after submit appears to have had the same problem as me, but there is no mention on how/if he resolved it.

Here's some code on how to repeat it (tested in IE8 Beta2, but had same problem in IE7)

My aspx code

<%@ Page Language="C#" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<script language="javascript" type="text/javascript">
    function btn_onClick()
    {
        var chk = document.getElementById("chk");
        if(chk.checked)
        {
            var btn = document.getElementById("btn");
            btn.disabled = true;
        }
    }
</script>
<body>
    <form id="form1" runat="server">
        <asp:Literal ID="lit" Text="--:--:--" runat="server" />
        <br />
        <asp:Button ID="btn" Text="Submit" runat="server" />
        <br />
        <input type="checkbox" id="chk" />Disable button on first click
    </form>
</body>
</html>

My cs code

using System;

public partial class _Default : System.Web.UI.Page 
{
    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);
        btn.Click += new EventHandler(btn_Click);
        btn.OnClientClick = "btn_onClick();";
    }

    void btn_Click(object sender, EventArgs e)
    {
        lit.Text = DateTime.Now.ToString("HH:mm:ss");
    }
}

Notice that when you click the button, a postback occurs, and the time is updated. But when you check the check box, the next time you click the button, the button is disabled (as expected), but never does the postback.

WHAT THE HECK AM I MISSING HERE???

Thanks in advance.

Answers:

Answer

I think you're just missing this tag:

UseSubmitBehavior="false"

Try it like this:

<asp:Button ID="btnUpdate" runat="server" UseSubmitBehavior="false" OnClientClick="if(Page_ClientValidate()) { this.disabled = true; } else {return false;}" Text = "Update" CssClass="button" OnClick="btnUpdate_Click" ValidationGroup="vgNew"/>

Explanation

Answer

fallen888 is right, your approach doesn't work cross-browser. I use this little snippet to prevent double-click.

Answer

UseSubmitBehavior="false" converts submit button to normal button (<input type="button">). If you don't want this to happen, you can hide submit button and immediately insert disabled button on its place. Because this happens so quickly it will look as button becoming disabled to user. Details are at the blog of Josh Stodola.

Code example (jQuery):

$("#<%= btnSubmit.ClientID %>").click(function()
{
  $(this)
    .hide()
    .after('<input type="button" value="Please Wait..." disabled="disabled" />');
});
Answer

"Disabling" HTML controls doesn't always produce consistent behavior in all major browsers. So I try to stay away from doing that on the client-side, because (working with the ASP.NET model) you need to keep track of element's state on client and server in that case.

What I'd do is move button off the visible part of the window by switching the button's className to a CSS class that contains the following:

.hiddenButton
{
  position: absolute;
  top: -1000px;
  left: -1000px;
}

Now, what to put in place of the button?

  1. Either an image that looks like a disabled button
  2. Or just plain text that says "Please wait..."

And this can be done the same way but in reverse. Start with the element being hidden at page load and then switch to a visible className on form submit.

Answer

We use the following JQuery script, to disable all buttons (input type=submit and button), when one button is clicked.

We just included the script in a global JavaScript file, so we don't have to do remember anything when creating new buttons.

$(document).ready(function() {
    $(":button,:submit").bind("click", function() {
        setTimeout(function() {
            $(":button,:submit").attr("disabled", "true");
        }, 0);
    });
});

This script could easily be extended with a check for Page_ClientValidate().

Answer
document.getElementById('form1').onsubmit = function() {
    document.getElementById('btn').disabled = true;
};
Answer

This is the correct and simple way to do this:

It works in all browsers (unlike the accepted solution above).

Create a helper method in your application (say in a Utlity Namespace):

    Public Shared Sub PreventMultipleClicks(ByRef button As System.Web.UI.WebControls.Button, ByRef page As System.Web.UI.Page)
        button.Attributes.Add("onclick", "this.disabled=true;" + page.ClientScript.GetPostBackEventReference(button, String.Empty).ToString)
    End Sub

Now from the code behind of each of your web pages you can simply call:

    Utility.PreventMultipleClicks(button1, page)

where button1 is the the button you want to prevent multiple clicks.

What this does is simply sets the on click handler to: this.disabled=true

and then appends the buttons own post back handler, so we get:

onclick="this.disabled=true";__doPostBack('ID$ID','');"

This does not break the default behaviour of the page and works in all browsers as expected.

Enjoy!

Answer

For debugging purposes, what happens if you put an else clause against the if(chk.checked)?

Answer

Make sure that your javascript function returns true (or a value that would evaluate to boolean true), otherwise the form won't get submitted.

function btn_click()
var chk = document.getElementById("chk");
    if(chk.checked)
    {
            var btn = document.getElementById("btn");
            btn.disabled = true;
            return true;   //this enables the controls action to propagate
    }
    else    return false;  //this prevents it from propagating
}
Answer

FOR JQUERY USERS

You will get into all sorts of problems trying to add javascript directly to the onClick event on ASP.NET buttons when using jQuery event listeners.

I found the best way to disable buttons and get the postback to work was to do something like this:

    $(buttonID).bind('click', function (e) {

        if (ValidateForm(e)) {

            //client side validation ok!
            //disable the button:
            $(buttonID).attr("disabled", true);

            //force a postback:
            try {
                __doPostBack($(buttonID).attr("name"), "");
                return true;
            } catch (err) {
                return true;
            }

        }
        //client side validation failed!
        return false;
    });

Where ValidateForm is your custom validation function which returns true or false if your form validates client side.

And buttonID is the id of your button such as '#button1'

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