Rewriting permalinks with custom posts

Question

I've created a custom post type, let's call it 'product'. The site is also bilingual, without any plugins, where I place localised pages under parent language pages, such as:

• English
  • Page 1
  • Page 2
  • Page 3
• French
  • Paginer 1
  • Paginer 2
  • Paginer 3

And so on. This means that my URLs are like /%language%/%pagename%, eg /en/page_1.

My custom post has bilingual fields for simple localisation but the problem is getting the correct language passed to their public page. For example the page where I list the custom posts exists in all languages and creates a URL like /%language%/parent_page/%custom_post_name%, eg /en/parent_page/a_custom_product.

The weird thing is that the links work perfectly but WordPress doesn't a rewrite of the URL so that it becomes /%post_type%/%custom_post_name%/ eg /product/a_custom_product and because we've now lost the language part I can't localise it.

I've created a function for the filter generate_rewrite_rules:

global $wp_rewrite;

$wp_rewrite->add_rewrite_tag( '%lang%', '(.+?)', 'lang=' );

$n  = array(
    '([\w]{2})/products/([^/])/?'   => 'index.php?pagename=$2&lang=$1'
);

return $n + $r->rules;

I've also flushed the permalinks and what not, I'm just interested to why WordPress rewrites the URL and how I can stop it becoming the former.

Answer 1

Oh dear, turns out I need to touch up on my regex, the second match only matches one character. It ought to be:

'([\w]{2})/the-wines/([^/]+)/?' => 'index.php?pagename=$matches[2]&lang=$matches[1]'