如何通过Select onChange与Submit Button提交表单

Question

I need assistance determining when my form was submitted via an onChange event for a Select as opposed to the user clicking on the Submit button.

To complicate matters, I need to be able to identify the difference in PHP.

Sample HTML:

<form name='editdata' method='post' action='/editpage/recordnumber'>
<select name='select1' onchange='this.form.submit()'><options...></select> 
<select name='select2' onchange='this.form.submit()'><options...></select>
<select name='select3' onchange='this.form.submit()'><options...></select> 
<input type='submit' value='Submit' />
</form>

Ultimately, I just need something to latch onto using PHP that identifies whether the form was submitted by an onChange event or by a press of the Submit button.

So far I have found that I can name my submit button 'submit'. This will set $_POST['submit'], thereby telling me that the user clicked the button. However, my onChange event this.form.submit() which is applied to a couple of my Selects stops functioning when I add the name attribute to my submit button.

If I could add some sort of queryString to the end of my submit URL with one method or the other, I think that would get the job done.

Answer 1

You could set a hidden field which gets updated by the event:

<form name='editdata' method='post' action='/editpage/recordnumber'>
<input type="hidden" name="submitted_on_change" value="0">
<select name='select1' onchange='form_submit()'><options...></select> 
<select name='select2' onchange='form_submit()'><options...></select>
<select name='select3' onchange='form_submit()'><options...></select> 
<input type='submit' value='Submit' />
</form>

<script>
var form_submit = function() {
   // update the hidden field to 1
   // then submit the form
}
</script>