I have a form written in the usual way. After submitting, if there are errors in the form, the form page itself is the target of the redirect, with a query string appended. The query string contains the error messages, but also the values submitted with the form. The query string and its format are provided by a 3rd-party, so I cannot switch to using POST, nor make any other changes on their processing logic. I just get the string and make the best of it.

Since the URL is "different", the form's values aren't preserved. The browser treats it as a fresh form and therefore blanks it. Not good, since the user won't want to re-enter everything. So, the first step was deciding whether to use JavaScript or PHP to repopulate the form, and I went with PHP.

Consequently, the form now has entries that look a little something like this:

<li id="li_business_years" >
  <label class="description" for="partner_business_years">How many years have you been in business?</label>
    <input id="partner_business_years" name="partner_business_years" class="element text small" type="text" maxlength="255" value="<?php echo $_GET['partner_business_years']; ?>"/>

Is this considered a ridiculous approach? If I used JavaScript, I could use an iterator to run through all the fields in one little loop, instead of individually populating each value attribute with PHP. But server-side seems to be the right place to do this since the form doesn't otherwise rely on JavaScript.

The next question: I have some Yes/No questions in radio button form. The query string will therefore contain values like will_relocate=yes. In my mind, I want to just say "Select the appropriate radio based on the query string", but there's no real concept of selecting for radios... there's a shared name with different value options.

Here's the original HTML:

  <input id="relocate_1" name="will_relocate" class="element radio" type="radio" value="yes" />
<label class="choice">Yes</label>
  <input id="relocate_2" name="will_relocate" class="element radio" type="radio" value="no" />
  <label class="choice">No</label>

I can get it working by doing something like this:

<input id="relocate_2" name="will_relocate" class="element radio" type="radio" value="no" <?php if($_GET['will_relocate'] && $_GET['will_relocate'] == "no") { echo 'checked'; } ?>/>

(with a matching one for "yes"... and as many pairs of these as needed)

But it strikes me as hideous. I'm just a hack at PHP, and I'm sure I could break this out into a function, but I would still have a pair of <?php selectRadio('will_relocate') ?> - type calls throughout my document, which is barely better.

Any ideas? Is my approach just completely nasty from the get-go? Should I use JavaScript after all?

I'm open to JavaScript-based suggestions for form re-populating, but not as the sole validator (I don't have and wouldn't choose that option).

  • \$\begingroup\$ Rather than unpacking the returned form contents from your PHP validator, have you considered doing client-side form validation in JavaScript? \$\endgroup\$
    – msanford
    Jun 26, 2012 at 16:11
  • 3
    \$\begingroup\$ I would never do client-side validation "only". It's a nice-to-have and I will probably implement it in some variety, but sanitizing on the server-side is a must-have. More to the point, though, I have no choice. If the form encounters an error on the server side, it WILL redirect to this page and I will want the form to be pre-filled. Might be a JavaScript snippet that will cookie and restore a form, though. Could be a decent compromise. \$\endgroup\$ Jun 26, 2012 at 16:19
  • \$\begingroup\$ Greg, I agree. There's always the possibility that someone might have JavaScript disabled, for example. \$\endgroup\$
    – msanford
    Jun 26, 2012 at 18:24

1 Answer 1


I went ahead with the one-by-one re-populating from GET (on a timeline and all that!). The form doesn't need to be highly reusable and won't be modified very frequently after roll-out, so in this particular case, it was a matter of 'getr done' rather than 'getr done the best way'.

For the radio buttons, I ended up with a series of these:

  <input id="partner_systemIntegration_1" name="partner_systemIntegration" class="element radio" type="radio" value="yes"  <?php if(($_GET['partner_systemIntegration']) && $_GET['partner_systemIntegration'] == "yes") { echo 'checked'; } ?> />
  <label class="choice" for="partner_systemIntegration_1">Yes</label>
  <input id="partner_systemIntegration_2" name="partner_systemIntegration" class="element radio" type="radio" value="no"  <?php if(($_GET['partner_systemIntegration']) && $_GET['partner_systemIntegration'] == "no") { echo 'checked'; } ?>  />
  <label class="choice" for="partner_systemIntegration_2">No</label>

It's klunky, but when I tried to break it out into a function it failed. I'm using WordPress and a plugin that allowed PHP in the post/page content itself. When trying to define and use a function, I got some sort of eval error/warning, so I'm just doing it one at a time. Not the epitome of elegance and not my ideal choice, but now I can move on.


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