Change URL on submit form - forms

Question

So I am trying to make a simple external popup that has 1 pull down menu for category and 4 columns of checkboxes as tags. (this is to feed a wordpress search engine plugin)
I use regular form submit for this but I end up with this as final URL:
Site.com/?category_name=VALUE&tag=TAG1&tag=TAG2&tag=TAG3
But I want my URL to be like this:
Site.com/?category_name=VALUE&tag=tag1+tag2+tag3
Could anyone point me in the right direction into achieving this?
CATEGORY_NAME is for searching a specific WordPress category
and the TAGS are regular post tags.

Answer 1

You can't do that with a checkbox. That is not how checkboxes work. It is not a choice, really. It the way that HTML, PHP, and your browser(s) are built.
Additionally, what you have done won't work. You've set the same variable to several different fields. Each time you set is, you overwrite the previous value. While your URL may look like ?category_name=VALUE&tag=TAG1&tag=TAG2&tag=TAG3 if you were to add var_dump($_GET); to your script you'd see that the only thing PHP sees is the last one-- tag=TAG3.
You can get the code working by using square brackets-- []-- in the checkbox names. An example in very minimal code (for demonstration purposes only):
echo '<form>';
echo '<input type="checkbox" name="tag[]" value="tag1">';
echo '<input type="checkbox" name="tag[]" value="tag2">';
echo '<input type="checkbox" name="tag[]" value="tag3">';
echo '<input type="checkbox" name="tag[]" value="tag4">';
echo '<input type="checkbox" name="tag[]" value="tag5">';
echo '<input type="checkbox" name="tag[]" value="tag6">';
echo '<input type="submit" value="Clickie">';
echo '</form>';
The 'tag' part of you URLs will look like this however:
&tag[]=tag1&tag[]=tag4&tag[]=tag6
That is just how checkboxes work. There are two workarounds that I can think of.
The first is to use Javascript to populate a hidden field in your form.
echo '<form>';
echo '<input type="hidden" name="tag" value="">';
echo '<input type="checkbox" value="tag1">';
echo '<input type="checkbox" value="tag2">';
echo '<input type="checkbox" value="tag3">';
echo '<input type="checkbox" value="tag4">';
echo '<input type="checkbox" value="tag5">';
echo '<input type="checkbox" value="tag6">';
echo '<input type="submit" value="Clickie">';
echo '</form>';
You would have your Javascript watch for clicks on those checkboxes and fill the value into the hidden tag field. In order to get the URL you want you have to remove the name from the checkboxes, which makes this form entirely dependent upon Javascript. Without Javascript it won't work. I consider that bad design.
The other option is to use mod_rewrite to try to rewrite your URL, but honestly, I don't know if mod_rewrite is capable of the complex regex you would need to make that work.
I don't think either workaround in worth the effort or the price. I would suggest you use the square brackets and process the array at the receiving end. In other words, if you have &tag[]=tag1&tag[]=tag4&tag[]=tag6 then this will get a string like what you want in your URL:
if (isset($_GET['tag'])) {
$tstr = implode('+',$_GET['tag']);
}
echo $tstr;
You can use that in your search function, whatever you are using for that.

Answer 2

This is what I did. Instead of adding a extra function to my wordpress (which was causing some unexpected error when testing deeper) I simply created a PHP to catch the URL before submiting further.
This is what it looks like:
<?php
if (isset($_GET['tag'])) {
$tstr = implode('+',$_GET['tag']);
}
$cat = ($_GET['category_name']);
header("Location: http://url.com/?category_name=$cat&tag=$tstr");
?>
I don't know if this is correct or secure, but it works :D
Thanks for your help !