Can I determine which Submit button was used in javascript?

Question

I have a very simple form with a name field and two submit buttons: 'change' and 'delete'. I need to do some form validation in javascript when the form is submitted so I need to know which button was clicked. If the user hits the enter key, the 'change' value is the one that makes it to the server. So really, I just need to know if the 'delete' button was clicked or not.

Can I determine which button was clicked? Or do I need to change the 'delete' button from a submit to a regular button and catch its onclick event to submit the form?

The form looks like this:

 <form action="update.php" method="post" onsubmit="return checkForm(this);">
    <input type="text" name="tagName" size="30" value="name goes here" />
    <input type="hidden" name="tagID" value="1" />
    <input type="submit" name="submit" value="Change" />
    <input type="submit" name="submit" value="Delete" />
 </form>

In the checkForm() function, form["submit"] is a node list, not a single element I can grab the value of.

Answer 1

Here's an unobtrusive approach using jQuery...

$(function ()
{
    // for each form on the page...
    $("form").each(function ()
    {
        var that = $(this); // define context and reference

        /* for each of the submit-inputs - in each of the forms on
           the page - assign click and keypress event */
        $("input:submit", that).bind("click keypress", function ()
        {
            // store the id of the submit-input on it's enclosing form
            that.data("callerid", this.id);
        });
    });


    // assign submit-event to all forms on the page
    $("form").submit(function ()
    {
        /* retrieve the id of the input that was clicked, stored on
           it's enclosing form */
        var callerId = $(this).data("callerid");

        // determine appropriate action(s)
        if (callerId == "delete") // do stuff...

        if (callerId == "change") // do stuff...

        /* note: you can return false to prevent the default behavior
           of the form--that is; stop the page from submitting */ 
    });
});

Note: this code is using the id-property to reference elements, so you have to update your markup. If you want me to update the code in my answer to make use of the name-attribute to determine appropriate actions, let me know.

Answer 2

You could also use the onclick event in a number of different ways to address the problem.

For instance:

<input type="submit" name="submit" value="Delete" 
       onclick="return TryingToDelete();" />

In the TryingToDelete() function in JavaScript, do what you want, then return false if do not want the delete to proceed.