The script below allows you to specify the path to one WordPress installation.. For multiple sites/installs just put this script in a loop.

Thanks to wp-cli for pointing me in the right direction.

// specify path to your wordpress root - no trailing slash
$wp_root = '/path/to/wordpress/root';
 
// load wordpress
require "{$wp_root}/wp-load.php";
 
// ensure we don't run out of memory
@ini_set( 'memory_limit', -1 );
 
// load admin API
require "{$wp_root}/wp-admin/includes/admin.php";
 
// load upgrade API
require "{$wp_root}/wp-admin/includes/upgrade.php";
 
// upgrade database
wp_upgrade();

For anyone comfortable with editing code, it’s easy enough to switch to HTML mode and add the class attribute manually to the desired element. But for most people, it’s far easier to select the text or image, then choose the desired style from a dropdown.

To set up this capability we need to:

1. hook into the tiny_mce_before_init filter
2. define the list of classes we wish to appear in the dropdown
3. activate the “Styles” dropdown in the editor

The format for the custom class list is {label}={class-name} seperated by semi-colons,
e.g.
“Special Style 1=special-1;Special Style 2=special-2;Special Style 3=special-3″

Using this example list of classes, the code which can go in your functions.php file is as follows:

add_filter('tiny_mce_before_init', 'add_custom_classes');
function add_custom_classes($arr_options) {
	$arr_options['theme_advanced_styles'] = "Special Style 1=special-1;Special Style 2=special-2;Special Style 3=special-3";
	$arr_options['theme_advanced_buttons2_add_before'] = "styleselect";
	return $arr_options;
}

Note: Prior to WordPress 3.1, the “Insert/edit link” dialog included a “class” drop down, which was populated by the same theme_advanced_styles list we have used here. In version 3.1 this drop down was removed by the core dev team. The technique described in this post is one way to work around this update to the WordPress admin.

You essentially need to tell WordPress to use a different version, by way of the functions wp_deregister_script and wp_register_script.

FYI at the time of writing, I’m using Fancybox Version 1.3.4 which plays nice with jQuery 1.4.3

Here’s the PHP code to go in your functions.php:

function my_enqueue_scripts() {
	wp_deregister_script('jquery');
	wp_register_script('jquery', 'http://ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js');
	wp_enqueue_script('jquery');
}
 
add_action('wp_enqueue_scripts', 'my_enqueue_scripts');

For more information on wp_enqueue_script, see the codex:
http://codex.wordpress.org/Function_Reference/wp_enqueue_script

Check out Fancybox – jQuery Plugin here:
http://fancybox.net

Example scenario:

You need a conditional tag to use in your theme template, which checks if a navigation item is “current” or not. If it’s current you want to highlight it somehow using CSS.

Working example:

On Melissa’s website, the top navigation is a list of pages.
Each tutorial on her site is a child page of the main Tutorials page.
When you are viewing the Pop Art Tutorial, the little triangle above the main nav indicates that you are in the Tutorials section of the site.

Example theme code

The main nav is an unordered list, here’s the list item for Tutorials:

<li <?php if (is_page_or_descendant('Tutorials')) echo 'class="current"'; ?>>
	<a href="/tutorials">Tutorials</a>
</li>

This code checks if the current page is ‘Tutorials’ or a descendant of it.
If so, then it adds the class=”current” attribute to the list item.
CSS and jQuery are then used to position the triangle above it.

Function Definition

bool is_page_or_descendant($page)

returns TRUE if the page you’re viewing is the specified page or a descendant of it

Function Parameters

$page
(mixed) (required) Page specified by ID (integer), title (string) or path (string)

Function Code

I hope this function is as useful for you as it is for me, enjoy

function is_page_or_descendant($page) {
	if (!is_page()) return false; 
 
	// retrieve page being currently viewed
	global $wp_query;
	$obj_current_page = $wp_query->get_queried_object();
	if (empty($obj_current_page->ID)) return false; 
 
	// retrieve specified page (ID, title or path)
	if (is_numeric($page)) $obj_specified_page = get_page($page);
	else $obj_specified_page = ($page_by_path = get_page_by_path($page)) ? $page_by_path : get_page_by_title($page);
	if (empty($obj_specified_page->ID)) return false;
 
	return ($obj_specified_page->ID == $obj_current_page->ID or $obj_specified_page->ID == $obj_current_page->post_parent or in_array($obj_specified_page->ID, get_post_ancestors($obj_current_page->ID)));
}

Open up your functions.php file and add the following code:

function enable_more_buttons($buttons) {
  $buttons[] = 'hr';
 
  /* 
  Repeat with any other buttons you want to add, e.g.
	  $buttons[] = 'fontselect';
	  $buttons[] = 'sup';
  */
 
  return $buttons;
}
add_filter("mce_buttons", "enable_more_buttons");

The idea here is that you are tapping into the filter hooks which are applied to each row of buttons on the editor toolbar.

The example above adds the <hr> button to the first row of buttons. If you’d like to add to the second row you’d use the mce_buttons_2 filter hook, etc etc.

add_filter("mce_buttons_2", "enable_more_buttons"); // add to second row
//add_filter("mce_buttons_3", "enable_more_buttons"); // add to third row

Hope you find this useful

It looks like this:

<meta name="generator" content="WordPress 2.9.0" />

To remove this meta tag, simply add the following line to your functions.php file in your theme:

remove_action('wp_head', 'wp_generator');

You have a couple of good options here:
1. create a new WP_Query object, or
2. use the get_posts() function.

Note: Using query_posts() is a bad option as it will upset your “main loop”

Both take pretty much the same arguments as query_posts() – see a list here.

Example usage of WP_Query:

$featured_category_id = 10;
$args = array('posts_per_page'=>3, 'cat'=>$featured_category_id);
$query = new WP_Query($args);
 
while ($query->have_posts()) : $query->the_post();
	the_title('<h3>', '</h3>');
endwhile;

Example usage of get_posts():

$featured_category_id = 10;
$args = array('numberposts'=>3, 'cat'=>$featured_category_id);
 
foreach (get_posts($args) as $post):
	the_title('<h3>', '</h3>');
endforeach;

in_category_extended() is designed to extend the functionality of in_category() in the following ways:

1. test if the current post is assigned to the specified category OR any descendant categories
2. return TRUE if you are viewing the specified category page OR any descendant category pages

Sure, you can do this a bunch of different ways, using multiple functions and code snippets, but I want a single boolean PHP function to use in my templates.

Example Usage

The main navigation consists of category tabs with on/off states.
If I’m viewing a post OR a category page which is related to the “development” category, then I want to apply a class="current" to the development tab element, which I can then style accordingly with CSS.

class="<?= in_category_extended('development') ? 'current' : '' ?>"

Function Definition

bool in_category_extended($category)

returns TRUE if the current webpage is related to the specified category

Function Parameters

$category
(mixed) (required) Category specified by ID (integer), or slug (string)

Function Code

This function has come in very handy for me – I hope you find it useful too!

function in_category_extended($category) {
 
	// easy out
	if (!(is_category() or is_single())) return false;
 
	// retrieve specified category (ID or slug)
	$obj_specified_category = is_numeric($category) ? get_category($category) : get_category_by_slug($category);
	if (empty($obj_specified_category->cat_ID)) return false;
 
	// we're viewing a category
	if (is_category()) {
		$current_category_ID = get_query_var('cat');
		return ($obj_specified_category->cat_ID == $current_category_ID or cat_is_ancestor_of($obj_specified_category->cat_ID,$current_category_ID));
	}
 
	// we're viewing a post
	else {
		global $wp_query;
		$obj_post = $wp_query->get_queried_object();
		if (empty($obj_post->ID)) return false; 
 
		if (in_category($obj_specified_category->cat_ID, $obj_post->ID)) return true;
		else return in_category(get_term_children($obj_specified_category->cat_ID, 'category'), $obj_post->ID);
	}
}