PHP variable in javascript ?

[capt_nemo777]

Hi,

is it cool/possible to use a php variable inside the javascript ?
i have this hidden html form field

PHP Code:

<?php $unique = md5(uniqid()); ?>
<input type="hidden" name="unique" id="<?php echo $unique; ?>" value="" />

then i have this javascript

PHP Code:

var hiddenfield = document.getElementById('<?php echo $unique; ?>');
hiddenfield.value = new Date().getTime();

LOL it doesn't work, can somebody help me please ?

[Old Pedant]

That will work--though it's a bit of overkill--*IF* you create the PHP variable at the very top of your PHP page, so it has the same value (and is available when needed) throughout the entire page.

Re a bit of overkill: Unless you have multiple <input> fields all named "unique", you can get a reference to that field by just doing

    var hiddenfield = document.YourFormName.unique;

[capt_nemo777]

Originally Posted by Old Pedant

That will work--though it's a bit of overkill--*IF* you create the PHP variable at the very top of your PHP page, so it has the same value (and is available when needed) throughout the entire page.

Re a bit of overkill: Unless you have multiple <input> fields all named "unique", you can get a reference to that field by just doing

    var hiddenfield = document.YourFormName.unique;

I have multiple rows that's why I have to generate unique id for each, and they were all named unique LOL, what should I do?, should I use a randomly generated php stuff and get it referenced via js like this ?

var hiddenfield = document.myFormName.<?php echo $unique; ?>

is that valid or ?

I also tried this

var hidden = document.myFormName."<?php echo $unique; ?>"
hidden.value  = new Date().getTime();

where $unique is md5(uniqid())
and Tadaa!!!..it didn't work lol

[Old Pedant]

Ummm....but how does you JS code know WHICH ONE of those many <input>s it should be referring to???

Let's write this in pure HTML just to demo:

<input type="hidden" name="unique" id="x7312" value="" />
<input type="hidden" name="unique" id="ar541" value="" />
<input type="hidden" name="unique" id="p819" value="" />
<input type="hidden" name="unique" id="g713" value="" />

Okay, so now your JS code does:

var hidden = document.getElementById("??? what do you put here???");

See what I mean? WHICH ONE of those fields do you want to get in the JS code???

Incidentally, if this <form> is going to be sent to a subsequent PHP page, and if you want to be able to get the values of any and all of those hidden fields on that PHP page, then you *must* use

<input type="hidden" name="unique[]" id="..whatever.." value="" />

Same as when you use multiple checkboxes with the same name.

Not to ask a dumb *** question, but would it be adequate to do this???

<?php
$unique = 0;
while ( ... some loop creating all this stuff ... )
{
    ++$unique;
    ...

?>
    ...
    <input type="hidden" name="unique<?php echo unique;?>" value="" />
    ...
<?php 
}
?>

And now your JS code can do:

     var which = 7; // or any other number
     var hidden = document.FormName.elements["unique"+which];
    ...

And now, also, each of your form fields has a different name and you don't have to use [] to make them accessible in the subsequent PHP page.

[Old Pedant]

Oh, by the way: You can't start an ID with a digit. If your hash function returns only numbers, then add a single letter prefix:

<input type="hidden" name="unique" id="U<?php echo $unique; ?>" value="" />

and then

var hiddenfield = document.getElementById('U<?php echo $unique; ?>');

That assume you decide to stick with your original scheme. Which I'm skeptical of for other reasons as noted above.

[capt_nemo777]

I managed to make the id of each and every row unique through the while loop
but am still have trouble with the JS stuff when trying to set the value of each unique row

      var number = 100;
      var hiddenfield = document.test.name["unique"+ number];
      hiddenfield.value = new Date().getTime();

OR

      var number = 100;
      var hiddenfield = document.getElementById("unique" + number);
      hiddenfield.value = new Date().getTime()

[Old Pedant]

No no no...

A name is *NOT* an ID!

So

      var number = 100;
      var hiddenfield = document.getElementById("unique" + number);

isn't even close. And name is *NOT* an indexable property of a form, so this

      var hiddenfield = document.test.name["unique"+ number];

makes no sense. (document.test.name would give you, what else, "test"--the name of the form named "test").

Try:

      var number = 100;
      var hiddenfield = document.test.elements["unique" + number];

With modern browsers, you can omit the elements[] as the implied collection of a <form> *is* the elements, so this should work as well:

      var number = 100;
      var hiddenfield = document.test["unique" + number];

Don't confuse names and ids; they aren't at all the same thing. [Except that in MSIE if you don't give an ID to a form field, then you can refer to it by ID and it promotes the name to be the ID. But please don't do this. It only work in MSIE in any case. And I think it *might* be fixed in MSIE 8.]

[capt_nemo777]

sir,
i did all the tips you gave me, none worked

      var number = 100;
      var hiddenfield = document.test.elements["unique" + number];
      hiddenfield.value = new Date().getTime();

or even this

      var number = 100;
      var hiddenfield = document.test["unique" + number];

btw here's my php code

PHP Code:

    <?php echo form_open('task/startdate',array("name"=>"test")); ?>
    <?php $name = 0; while($name < sizeof($task->result())):?>
      <?php foreach($task->result() as $row): ?>
        <tr>
        <td><a title="<?php echo $row->descr; ?>" href="#"><?php echo $row->title; ?></a></td>
        <td><input type = "button" id =<?php echo $row->title; ?> value = "Unlocked" onmouseover = "asktolock(this.id)"  onclick = "lockme(this.id)"></td>
        <td><?php echo $row->assign_to; ?></td>
        <td><a id="txt"></a></td>
        <?php ++$name; ?>
        <?php $unique = 'U'.md5(uniqid()).$row->id; ?>
        <input type="hidden" name="unique<?php echo $name; ?>" id="<?php echo $unique; ?>" value="" />
        </tr>
     <?php endforeach; ?>
     <?php endwhile; ?>
    <?php echo form_close(); ?>

[Old Pedant]

Well, the bug must be in your PHP code.

Here's an all HTML example:

<!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">
<head>
<script style="text/javascript">
function doOne()
{
    var r = Math.floor( 10 * Math.random() ); // choose one at random
    var h = document.test["unique" + r];
    h.value = (new Date()).getTime();
}
</script>
</head>
<body>
<form name="test">
    <input name="unique0" id="asdfadsf" /><br/>
    <input name="unique1" id="qwerqwer" /><br/>
    <input name="unique2" id="ertyerty" /><br/>
    <input name="unique3" id="aaaaaaaa" /><br/>
    <input name="unique4" id="bbbbbbbb" /><br/>
    <input name="unique5" id="cccccccc" /><br/>
    <input name="unique6" id="dddddddd" /><br/>
    <input name="unique7" id="eeeeeeee" /><br/>
    <input name="unique8" id="ffffffff" /><br/>
    <input name="unique9" id="zambonis" /><br/>
    <br/>
    <input type="button" value="demo" onclick="doOne()"/>
</form>
</body>
</html>

As you can see, it works. It just picks one of the 10 inputs randomly, but the concept is right.

Bring up your PHP page in your browser and then do a VIEW==>>SOURCE to see the HTML you are generating. If you can't see the bug by doing that, show us the HTML.