Easiest way to simulate WordPress's URL resolution to retrieve post ID, etc?

Question

I'm curious if it is possible, in a plugin/custom code, to take an URL that has been generated by the currently running WordPress site & parse it to retrieve the $blog_id and $post_id?

ie. taking a string like "myblog.mysite.com/2012/03/16/whatever/" and determining that this is post #6 ("whatever") on blog #2 ("myblog").

I realize that I can probably strip the URL and parse the domain myself, but I hope that there might be recommended WordPress methods exposed to make this more robust across URL formats.

Answer 1

As Weston mentioned, if you're within WordPress and you know what blog the URL came from, then ask WordPress for the blog ID.

But if you're really, really sure there's no better method in this case than parsing a URL, then here you go:

$url = 'http://myblog.mysite.com/2012/03/16/whatever/';

$domain = parse_url( $url, PHP_URL_HOST );

// This could be dynamic but good enough for now
$subdomain = str_replace( '.mysite.com', '', $domain );

// Never use $blog_id for anything, you'll break tons of things
$parsed_blog_id = get_id_from_blogname( $subdomain );


// url_to_postid() only works for the current blog
switch_to_blog( $parsed_blog_id );

$post_id = url_to_postid( $url );

restore_current_blog();

Reference material:

http://codex.wordpress.org/Function_Reference/get_id_from_blogname

http://codex.wordpress.org/Function_Reference/url_to_postid

Answer 2

Plain and simple, to get the post id you just use:

<?php 
echo get_the_ID(); 
?>

That will echo out the post id.

And:

<?php 
echo get_current_blog_id(); 
?>

Will echo out the blog id.

http://codex.wordpress.org/Function_Reference/get_the_ID

and

http://codex.wordpress.org/Function_Reference/get_current_blog_id respectively

Answer 3

The best solution I've found for this is the Monkeyman Rewrite Analyzer plugin. It was written by a member of the WPSE community in response to a few similar requests some time ago.

You can give it any URL for your site, and it will tell you explicitly how that request will be mapped/interpreted by WordPress.

For example: