Changing Link Attributes for Wp_Link_Pages

Question

I'm wondering if there is any way to change the actual link itself for wp_link_pages. So right now, I have a simple code to display the pagination for a post, it looks like this:

<?php wp_link_pages( array( 'before' => '<div class="link-pages">' . __('Pages:', 'muimedia'), 'after' => '</div>',) ); ?>

It displays the Post pagination like so:

Pages: 1 2 3

Page one links two page one, page two links to page 2 etc. Now, I would like to add an attribute called fromwhere=news" to the pagination permalinks. So page 1, 2, and 3 pagination links would look like so.. mysite.com/somepost/post?fromwhere=news" instead of just mysite.com/somepost/post

I really hope this is possible, and if anyone could help me out, it would really mean a lot to me! And happy new years!!! :)

Answer 1

There is no filter for the URLs, and no filter for the complete output of wp_link_pages(). But you can get the output as string if you pass 'echo' => FALSE as argument.

There are four options:

1. Write a modified copy of the function with the URLs you need. You will miss all further improvements which may happen in core code.

2. Catch the output in a string and run a regex on that. Example:

   print preg_replace(
       '~(href=")([^"]+)~',
       '\1\2?from=' . $post->post_name,
       wp_link_pages( array ( 'echo' => FALSE ) )
   );
   

3. Use JavaScript to add the parameter.

4. Do nothing. Do not offer the same content – separate sub pages – with different URLs (a search result could link to a sub page too), and make external search engines like Google happy.