The Variable Toggle – The Daily WTF

A common class of bad code is the code which mixes server side code with client side code. This kind of thing:

<script>
    <?php if (someVal) { ?>
        var foo = <? echo someOtherVal ?>;
    <?php } else { ?>
        var foo = 5;
    <?php } ?>
</script>

We’ve seen it, we hate it, and is there really anything new to say about it?

Well, today’s anonymous submitter found an “interesting” take on the pattern.

<script>
    if(linkfromwhere_srfid=='vff')
      {
    <?php
    $vff = 1;
    ?>
      }
</script>

Here, they have a client-side conditional, and based on that conditional, they attempt to set a variable on the server side. This does not work. This cannot work: the PHP code executes on the server, the client code executes on the client, and you need to be a lot more thoughtful about how they interact than this.

And yet, the developer responsible has done this all over the code base, pushed the non-working code out to production, and when it doesn’t work, just adds bug tickets to the backlog to eventually figure out why- tickets that never get picked up, because there’s always something with a higher priority out there.