Include Wordpress Core into own Scripts

Question

I'm trying to "Import" the Wordpress core into an own script to use the functionality such as wp_query etc. I've created an script in a subdirectory (own framework) and want to extend it by wordpress, but everytime the script throws an error:

Fatal error: Call to a member function add_rewrite_tag() on a non-object in .../wordpress/wp-includes/taxonomy.php on line 333

such as (when I remove the add_action( 'init', 'create_initial_taxonomies', 0 )):

Fatal error: Call to a member function add_rewrite_tag() on a non-object in .../wordpress/wp-includes/post.php on line 1006

The non-object is the $wp_rewrite-object. I've echo'ed something and figured out that first $wp_rewrite is valid and at the next call not. I've changed nothing at the WP core files.

I try to include the core by calling:

    require_once(BASE_PATH . 'wp-load.php');

Has anybody some ideas for me?

thanks

Answer 1

Short answer, do this:

define('WP_USE_THEMES', false);
global $wp, $wp_query, $wp_the_query, $wp_rewrite, $wp_did_header;
require(BASE_PATH . 'wp-load.php');

Long answer, it's a subtle gotcha around importing scripts with PHP.

If you define a local variable, outside of all functions, then it can be retrieved inside a function using 'global'. If you have a local variable inside a function, it cannot be retrieved later using global, unless it is defined as being global there and then.

The script 'wp-settings.php' is where the issue lies. It is included via your call to include 'wp-load.php'.

The variables defined there are not stated as being global; instead this is presumed because the script is always run outside of any functions, and so are automatically global. i.e.

$wordpress = 'foo';

function wordpressFunction() {
    global $wordpress;
}

Because you are importing the script within a function, they now become local variables. You are essentially doing:

function myFramework() {
    $wordpress = 'foo';

    function wordpressFunction() {
        global $wordpress;
    }
}

So the fix is to define them as global yourself before importing the script. Now $wp_query, and the others defined as global, are correctly found.

Answer 2

The easiest way to access everything wordpress has programmed in is to use the following:

require_once('/../../../wp-blog-header.php'); // Use actual root path to wp-blog-header.php
header("HTTP/1.0 200 OK");

Using the above code you'll get all functions you would normally get using a template with in WordPress. I've tried all the other methods listed above and this one is by far the best.

Answer 3

I had the same error. I wanted to get some articles along with permalinks. This helped:

global $wpdb, $wp_rewrite;
require '/(...)/wp-config.php';

$result = $wpdb->get_results( $wpdb->prepare( ... ) );
foreach( $result as &$item )
  $item->link = get_permalink( $item->ID );

I also found this useful in another case: http://www.stormyfrog.com/using-wpdb-outside-wordpress/