Title: Run PHP function from HTML hyperlink
Last modified: August 20, 2016

---

# Run PHP function from HTML hyperlink

 *  Resolved [thhhhh](https://wordpress.org/support/users/thhhhh/)
 * (@thhhhh)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/)
 * Hi all,
 * I’m trying to run a function to alter the post_type in my wordpress query string(
   or to add a new post type altogether). The function I’m using comes from here:
   [http://www.addedbytes.com/blog/code/php-querystring-functions/](http://www.addedbytes.com/blog/code/php-querystring-functions/)
 * Based on the examples in [this thread](http://board.phpbuilder.com/showthread.php?10324957-Using-hyperlink-to-call-php-function&p=10991056),
   I’ve written a sidebar that looks like this:
 *     ```
       <?php //add query to URL
       function add_querystring_var($url, $key, $value) {
           $url = preg_replace('/(.*)(?|&)' . $key . '=[^&]+?(&)(.*)/i', '$1$2$4', $url . '&');
           $url = substr($url, 0, -1);
           if (strpos($url, '?') === false) {
               return ($url . '?' . $key . '=' . $value);
           } else {
               return ($url . '&' . $key . '=' . $value);
           }
       }
       ?>
       <?php 
   
       if (isset($_GET['run'])) $linkchoice=$_GET['run'];
       else $linkchoice=''; 
   
       switch($linkchoice){ 
   
       case 'showAll' :
           add_querystring_var($url, 'post_type', '');
       	break; 
   
       case 'showAnimation' :
           add_querystring_var($url, 'post_type', 'animation');
           break; 
   
       case 'showPeople' :
           add_querystring_var($url, 'post_type', 'people');
           break; 
   
       case 'showStudios' :
           add_querystring_var($url, 'post_type', 'studios');
           break; 
   
       case 'showResources' :
           add_querystring_var($url, 'post_type', 'resources');
           break; 
   
       case 'showWiki' :
       	add_querystring_var($url, 'post_type', 'wiki');
       	break;
       default : ;
       } 
   
       ?> 
   
       <h2>Show... </h2>
       <a href="?run=showAll">All</a>
       <a href="?run=showAnimation">Animation</a>
       <a href="?run=showPeople">People</a>
       <a href="?run=showStudios">Studios</a>
       <a href="?run=showResources">Resources</a>
       <a href="?run=showWiki">Wiki</a><br /><br />
       ```
   
 * When I click any of these links, they take me to “mywebsite.com/?run=showX” –
   which in turn directs me to my front page. I think this means that the function
   is not running, and I’m wondering if anyone has any suggestions as to why. I’ve
   tried testing without the function, and with just echo functions generating text
   to indicate that a function has ran – and these haven’t done anything either.
   I still am directed to the url indicated in the link and nothing beyond that 
   seems to happen. Have I set the function to run incorrectly?
 * Thanks in advance for any help.

Viewing 8 replies - 1 through 8 (of 8 total)

 *  Thread Starter [thhhhh](https://wordpress.org/support/users/thhhhh/)
 * (@thhhhh)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323184)
 * Does anyone have any experience doing this? I’m willing coding strategy if I 
   can accomplish this another way. I don’t really know AJAX but it seems to me 
   like this piece of code here is doing nothing:
 *     ```
       if (isset($_GET['run'])) $linkchoice=$_GET['run'];
       else $linkchoice='';
       ```
   
 *  Thread Starter [thhhhh](https://wordpress.org/support/users/thhhhh/)
 * (@thhhhh)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323190)
 * Hi all,
 * I’ve rewritten this a bit to see if I can get it to work, following jquery ajax
   tutorials.
 * I have moved the PHP function I want to execute to my functions.php file. My 
   sidebar now looks like this:
 *     ```
       <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js">
       </script>
       <h2>Show... </h2>
       <script type="text/javascript">
       function showAll() {
           $.get("addquery.php", { value:"" });
           return false;
       }
       function showAnimation() {
           $.get("addquery.php", { value:"animation" });
           return false;
       }
       function showPeople() {
           $.get("addquery.php", { value:"people" });
           return false;
       }
       function showResources() {
           $.get("addquery.php", { value:"resources" });
           return false;
       }
       function showStudios() {
           $.get("addquery.php", { value:"studios" });
           return false;
       }
       function showWiki() {
           $.get("addquery.php", { value:"wiki" });
           return false;
       }
       </script>
       <a href="#" onclick="showAll();">All</a>
       <a href="#" onclick="showAnimation();">Animation</a>
       <a href="#" onclick="showPeople();">People</a>
       <a href="#" onclick="showStudios();">Studios</a>
       <a href="#" onclick="showResources();">Resources</a>
       <a href="#" onclick="showWiki();">Wiki</a><br /><br />
       <h2>Browse by topic... </h2>
       <?php if ( function_exists('dynamic_sidebar') && dynamic_sidebar(7) ) : else : ?>
       <?php endif; ?>
       ```
   
 * My “Addquery.php” file which I am using to execute the function looks like this:
 *     ```
       <?php
       $_GET['value'] = $value;
       add_querystring_var($url, 'post_type', $value);
       ?>
       ```
   
 * But when I run the functions, nothing happens. I can see in chrome that the browser
   is trying to access “mysite.com/addquery.php?value=wiki” correctly and that it
   is receiving an error. The error is “Failed to load resource: the server responded
   with a status of 500 (Internal Server Error)”
 * Does anyone have any suggestions for how I might proceed?
 *  Moderator [keesiemeijer](https://wordpress.org/support/users/keesiemeijer/)
 * (@keesiemeijer)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323191)
 * What is it exactly you want to do?
 * for adding or removing a query variable to the URL you can use:
    [http://codex.wordpress.org/Function_Reference/add_query_arg](http://codex.wordpress.org/Function_Reference/add_query_arg)
   [http://codex.wordpress.org/Function_Reference/remove_query_arg](http://codex.wordpress.org/Function_Reference/remove_query_arg)
 *  Thread Starter [thhhhh](https://wordpress.org/support/users/thhhhh/)
 * (@thhhhh)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323192)
 * keesiemeijer, thanks for responding! What I am trying to do is to make links 
   in my sidebar which add a post_type argument to the existing query string of 
   an archive page.
 * I didn’t know about these functions, hence why I was using the other ones. But
   I will definitely try them out. They look like they might do exactly what I was
   hoping for.
 *  Thread Starter [thhhhh](https://wordpress.org/support/users/thhhhh/)
 * (@thhhhh)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323193)
 * I’ve put in the new function but I still can’t figure out how to trigger it… 
   will keep plugging away
 *  Moderator [keesiemeijer](https://wordpress.org/support/users/keesiemeijer/)
 * (@keesiemeijer)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323194)
 * Try adding the links like this on your archive pages:
 *     ```
       <a href="<?php echo add_query_arg( 'myposttype', 'people' ); ?>">people<a>
       ```
   
 * With this in your theme’s functions.php you can add the post type to the normal
   post type “post” that’s normally displayed on archive pages:
 *     ```
       function add_post_type($query) {
         if (!is_admin() && $query->is_main_query()){
           if (isset($_GET['myposttype']) && $_GET['myposttype']) {
             $post_types = get_post_types(array('public' => true, '_builtin' => false), 'names', 'and');
             if(!empty($post_types) && in_array($_GET['myposttype'], (array) $post_types)) {
   
               // add the post type from the url to the normal "post" post type
               $query->set('post_type', array('post', $_GET['myposttype']));
   
             }
           }
         }
       };
       add_action('pre_get_posts','add_post_type');
       ```
   
 *  Thread Starter [thhhhh](https://wordpress.org/support/users/thhhhh/)
 * (@thhhhh)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323197)
 * Amazing!! Works perfectly!!
 * I was under the impression that a PHP function couldn’t be run straight out of
   an HTML link without a separate script or AJAX, but I guess I was mistaken! This
   is much cleaner (and more functional) than what I was attempting!
 * Thanks so much!
 *  Moderator [keesiemeijer](https://wordpress.org/support/users/keesiemeijer/)
 * (@keesiemeijer)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323198)
 * You’re welcome. I’m glad you got it resolved 🙂

Viewing 8 replies - 1 through 8 (of 8 total)

The topic ‘Run PHP function from HTML hyperlink’ is closed to new replies.

## Tags

 * [ajax](https://wordpress.org/support/topic-tag/ajax/)
 * [php function](https://wordpress.org/support/topic-tag/php-function/)
 * [Query String](https://wordpress.org/support/topic-tag/query-string/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 8 replies
 * 2 participants
 * Last reply from: [keesiemeijer](https://wordpress.org/support/users/keesiemeijer/)
 * Last activity: [13 years, 4 months ago](https://wordpress.org/support/topic/run-php-function-from-html-hyperlink/#post-3323198)
 * Status: resolved

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