Question

I was wondering if it is possible to save some data with PHP getting the value from a form placed in the page by javascript with document.write, the value of which has been set by javascript with document.getElementbyId(id).value.

I know that with .innerHTML() it doesn’t work, since the save button doesn’t get a value set with the .innerHTML() method.

So I was wondering, would it work if I have javascript place an input box with document.write and then its value is set by another js function?

Answer 1

Yes, as long as you place the <input> inside a form.

Here is a simple example:

PHP:

<?php
if( !empty( $_POST['hidden_input']))
{
    die( 'Value: ' . $_POST['hidden_input']);
}

HTML:

<form action="test.php" method="POST">
<script type="text/javascript">
    document.write( '<input id="hidden_input" type="hidden" name="hidden_input" value="0" />');
</script>
<input type="submit" name="submit" value="Submit" />
</form>

<script type="text/javascript">
    window.onload = function() {
        document.getElementById('hidden_input').value = 'Changed with JS';
    } 
</script>