I am trying to solve a rewrite problem but don’t fully understand how to read the below code.
I believe the event/industry/(.+)/?$' is stating the format I want in my new url after rewritten, which should be example.com/event/industry/someterm/
And this part appears to be the parameter. => 'index.php?post_type=eg_event&industry=' . $wp_rewrite->preg_index(1)
Is this a correct understanding?
What is telling this code what value to place in my new url where this is: (.+)/?$' Is it the $wp_rewrite->preg_index(1) and what exactly does the preg_index(1) mean?
$new_rules = array(
'event/industry/(.+)/?$' => 'index.php?post_type=eg_event&industry=' . $wp_rewrite->preg_index(1)
);
$wp_rewrite->rules = $new_rules + $wp_rewrite->rules;
}
Any assistance you can provide with helping me understand the logic above it much appreciated.
The above is the URL that will be rewritten behind the scenes. The brackets create what is known as a “backreference”.
The above is the actual URL that will be served to the browser.
So, http://yourdomain.com/event/industry/abc/ matches the rule “event/industry/(.+)/?$”. The term ‘abc’ becomes a backreference with index 1, because it matches the term enclosed in brackets.
When someone browses to that URL, the server will then silently rewrite that URL to “index.php?post_type=eg_event&industry=abc”, and serve that page instead. This “rewrite” is not visible to the browser/end-user.
$wp_rewrite->preg_index(1) simply refers to backreference with index 1.
You can have multiple backreferences. For instance:
Now this rule will match http://yourdomain.com/event/magic/def/.
This time, “magic” becomes backreference with index 1, while “def” becomes backreference with index 2.
So you could rewrite the rule to:
i.e. index.php?post_type=eg_event&magic=def