[javascript] Form onSubmit determine which submit button was pressed

I have a form with two submit buttons and some code:

HTML:

<input type="submit" name="save" value="Save" />
<input type="submit" name="saveAndAdd" value="Save and add another" />

JavaScript:

form.onSubmit = function(evnt) {
    // Do some asyncrhnous stuff, that will later on submit the form
    return false;
}

Of course the two submit buttons accomplish different things. Is there a way to find out in onSubmit which button was pressed, so later I could submit by doing thatButton.click()?

Ideally I would like to not modify the code for the buttons, just have a pure JavaScript addon that has this behavior.

I know that Firefox has evnt.explicitOriginalTarget, but I can't find anything for other browsers.

This question is related to javascript html

The answer is


Not in the submit event handler itself, no.

But what you can do is add click handlers to each submit which will inform the submit handler as to which was clicked.

Here's a full example (using jQuery for brevity)

<html>
<head>
  <title>Test Page</title>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
  <script type="text/javascript">

  jQuery(function($) {
      var submitActor = null;
      var $form = $('#test');
      var $submitActors = $form.find('input[type=submit]');

      $form.submit(function(event) {
          if (null === submitActor) {
              // If no actor is explicitly clicked, the browser will
              // automatically choose the first in source-order
              // so we do the same here
              submitActor = $submitActors[0];
          }

          console.log(submitActor.name);
          // alert(submitActor.name);

          return false;
      });

      $submitActors.click(function(event) {
          submitActor = this;
      });
  });

  </script>
</head>

<body>

  <form id="test">

    <input type="text" />

    <input type="submit" name="save" value="Save" />
    <input type="submit" name="saveAndAdd" value="Save and add another" />

  </form>

</body>
</html>

<form onsubmit="alert(this.submitted); return false;">
    <input onclick="this.form.submitted=this.value;" type="submit" value="Yes" />
    <input onclick="this.form.submitted=this.value;" type="submit" value="No" />
</form>

jsfiddle for the same


Why not loop through the inputs and then add onclick handlers to each?

You don't have to do this in HTML, but you can add a handler to each button like:

button.onclick = function(){ DoStuff(this.value); return false; } // return false; so that form does not submit

Then your function could "do stuff" according to whichever value you passed:

function DoStuff(val) {
    if( val === "Val 1" ) {
        // Do some stuff
    }
    // Do other stuff
}

All of the answers above are very good but I cleaned it up a little bit.

This solution automatically puts the name of the submit button pressed into the action hidden field. Both the javascript on the page and the server code can check the action hidden field value as needed.

The solution uses jquery to automatically apply to all submit buttons.

<input type="hidden" name="action" id="action" />
<script language="javascript" type="text/javascript">
    $(document).ready(function () {
        //when a submit button is clicked, put its name into the action hidden field
        $(":submit").click(function () { $("#action").val(this.name); });
    });
</script>
<input type="submit" class="bttn" value="<< Back" name="back" />
<input type="submit" class="bttn" value="Finish" name="finish" />
<input type="submit" class="bttn" value="Save" name="save" />
<input type="submit" class="bttn" value="Next >>" name="next" />
<input type="submit" class="bttn" value="Delete" name="delete" />
<input type="button" class="bttn" name="cancel" value="Cancel" onclick="window.close();" />

Then write code like this into your form submit handler.

 if ($("#action").val() == "delete") {
     return confirm("Are you sure you want to delete the selected item?");
 }

Bare bones, but confirmed working, example:

<script type="text/javascript">
var clicked;
function mysubmit() {
    alert(clicked);
}
</script>
<form action="" onsubmit="mysubmit();return false">
    <input type="submit" onclick="clicked='Save'" value="Save" />
    <input type="submit" onclick="clicked='Add'" value="Add" />
</form>

First Suggestion:

Create a Javascript Variable that will reference the button clicked. Lets call it buttonIndex

<input type="submit" onclick="buttonIndex=0;" name="save" value="Save" />
<input type="submit" onclick="buttonIndex=1;" name="saveAndAdd" value="Save and add another" />

Now, you can access that value. 0 means the save button was clicked, 1 means the saveAndAdd Button was clicked.

Second Suggestion

The way I would handle this is to create two JS functions that handle each of the two buttons.

First, make sure your form has a valid ID. For this example, I'll say the ID is "myForm"

change

<input type="submit" name="save" value="Save" />
<input type="submit" name="saveAndAdd" value="Save and add another" />

to

<input type="submit" onclick="submitFunc();return(false);" name="save" value="Save" />
<input type="submit" onclick="submitAndAddFunc();return(false);" name="saveAndAdd" value="Save and add 

the return(false) will prevent your form submission from actually processing, and call your custom functions, where you can submit the form later on.

Then your functions will work something like this...

function submitFunc(){
    // Do some asyncrhnous stuff, that will later on submit the form
    if (okToSubmit) {
        document.getElementById('myForm').submit();
    }
}
function submitAndAddFunc(){
    // Do some asyncrhnous stuff, that will later on submit the form
    if (okToSubmit) {
        document.getElementById('myForm').submit();
    }
}

I use Ext, so I ended up doing this:

var theForm = Ext.get("theform");
var inputButtons = Ext.DomQuery.jsSelect('input[type="submit"]', theForm.dom);
var inputButtonPressed = null;
for (var i = 0; i < inputButtons.length; i++) {
    Ext.fly(inputButtons[i]).on('click', function() {
        inputButtonPressed = this;
    }, inputButtons[i]);
}

and then when it was time submit I did

if (inputButtonPressed !== null) inputButtonPressed.click();
else theForm.dom.submit();

Wait, you say. This will loop if you're not careful. So, onSubmit must sometimes return true

// Notice I'm not using Ext here, because they can't stop the submit
theForm.dom.onsubmit = function () {
    if (gottaDoSomething) {
        // Do something asynchronous, call the two lines above when done.
        gottaDoSomething = false;
        return false;
    }
    return true;
}

OP stated he didn't want to modify the code for the buttons. This is the least-intrusive answer I could come up with using the other answers as a guide. It doesn't require additional hidden fields, allows you to leave the button code intact (sometimes you don't have access to what generates it), and gives you the info you were looking for from anywhere in your code...which button was used to submit the form. I haven't evaluated what happens if the user uses the Enter key to submit the form, rather than clicking.

<script language="javascript" type="text/javascript">

    var initiator = '';
    $(document).ready(function() {
        $(":submit").click(function() { initiator = this.name });
    });

</script>

Then you have access to the 'initiator' variable anywhere that might need to do the checking. Hope this helps.

~Spanky