How to pass on a value as parameter via url to another page

Question

I'm dealing with a problem I can't solve myself. I did a few hours of research about it, but I didn't manage to make it work. I want to send a parameter via the url to the page I'm forwarding to and based on the value of this I want to show a image. Im using the Hana Code Insert Plugin to get my js used in WP. I'm relatively new to WP and have little to no knowledge in PHP, so please consider this.

The Hana-contents are as following:

shortcut galleryLink and getSelected_05: http://www.abload.de/gallery.php?key=updfCGrl

The contents of the site are as following:

toat.me/test-for-ids/

Gallery: [hana-code-insert name='galleryLink' /] Finished...

toat.me/resize-your-image-now/

|img class="aligncenter size-full wp-image-119" alt="" src="http://toat.me/wp-content/uploads/2013/08/blank-t-shirt_white_big.jpg" width="700" height="700" /| [hana-code-insert name='getSelected_05' /]

Note: I had to replace the <> tags of the img with | in order to show it in this post. I'm looking forward to helpful answers.

Answer 1

If you are working in a php file such as a template, you can use $_GET to extract the url variables. For example, if your url was mydomain.com/page?color=blue you would print it on screen by:

<?php echo $_GET['color']; ?>

This would print "blue". So to make a conditional statement out of this, you could do:

<?php if( $_GET['color'] == 'blue' ) {
    echo '<img src=''>';
} elseif( $_GET['color'] == 'red' ) {
    //do something else
}

Query strings are stored in the $_GET variable as an associative array. Now, if you want to do query strings in Wordpress posts/pages, you need to create a function to read query strings via shortcode. It looked like you were doing this inside template files though so I will leave that solution out, unless you need it - then just let me know and I'll edit this.