A function is a sequence of program instructions that perform a specific task. It is packaged as a unit that can be used wherever the according task should be performed.

learn more… | top users | synonyms (2)

261
votes
108answers
131k views

Best Collection of Code for your functions.php file [closed]

Please vote on the question and any answers you find useful by clicking on the UP arrow on the left hand side of the question or answer. As with many others who are now viewing this post, I have been ...
38
votes
2answers
11k views

Between functions.php, widgets and plugins, which is loaded first?

Customer asks if a specific carousel plugin he uses can be widgetized. That means i should create a widget inside functions.php which calls the plugin's function. That means that the plugin's code has ...
27
votes
4answers
42k views

Changing Admin Menu Labels

I have spent the last day using the functions.php file to fully customize WordPress for my client sites. I am amazed at how much I have been able to accomplish and how much easier it will make things ...
27
votes
4answers
33k views

What's the difference between home_url() and site_url()

My understanding is that site_url() returns the location where the wordpress core files are. So, if my blog is hosted at http://example.com/blog then site_url() returns http://example.com/blog But ...
21
votes
7answers
59k views

How to include PHP files in plugins the correct way

My problem is when on the main plugin file I include a PHP file something like this: include(WP_PLUGIN_URL . '/wordpress-group-buying/ipn/paypal-ipn.php'); // or include_once(WP_PLUGIN_URL . ...
20
votes
7answers
30k views

remove empty paragraphs from the_content?

Hey guys, I simply want to prevent the creation of empty paragraphs in my wordpress post. That happens quite often when trying to manually space content. I don't know why this doesn't take effect? ...
18
votes
3answers
4k views

Where do I put the code snippets I found here or somewhere else on the web?

Many posts here or somewhere else contain code, but they do not say where to put it. Example: I have found this post: How do I turn off 301 redirecting posts (not canonical)? I'm a newbie with PHP. ...
16
votes
1answer
12k views

How to override parent functions in child themes?

I've been reading around and trying to figure out how to do this, but for some reason I can't seem to override parent functions in my child theme. I'm using TwentyTen as a parent - can anyone tell me ...
16
votes
4answers
276 views

How long does a deprecated function live in core?

I'm curious to find out the process/philosophy behind removing deprecated functions from core. The Codex says this: These functions below have been deprecated. That means they have been replaced ...
15
votes
4answers
13k views

How to customize the_archive_title()?

In my child theme's archive.php, I have the following code for displaying the title of my archive pages: <?php the_archive_title( '<h1 class="page-title">', '</h1>' ); ...
13
votes
1answer
14k views

Redeclare/Change Slug of a Plugin's Custom Post Type

Is it possible to redeclare/change the slug of a plugin's existing custom post type (without simply editing the plugin)? That is, if Plugin X creates a custom post type with the slug /uncookedtoast/, ...
12
votes
5answers
1k views

Best way of passing PHP variable between partials?

I have a variable in header.php, such as: $page_extra_title = get_post_meta($this_page->ID, "_theme_extra_title", true); Once I do: var_dump($page_extra_title); I always get NULL outside of ...
12
votes
2answers
12k views

Why use if function_exists?

I noticed a lot of developers of WordPress themes would use this in functions.php if (function_exists('register_nav_menus')) { register_nav_menus (array('primary' => 'Header Navigation')); } ...
11
votes
4answers
23k views

How to manually fix the WordPress gallery code using PHP in functions.php?

It's been talked many times that Wordpress outputs some really bad code for the built-in gallery function. This is the core code responsible for the gallery output (in /wp-includes/media.php): ...
11
votes
3answers
471 views

How to deprecate a function used in a plugin?

One of the functions I'm using in my plugin is polluting the global scope with a name that could collide with another function (used in another plugin). So, I guess I should deprecate it. But how ...
11
votes
1answer
6k views

Solution to render Shortcodes in Admin Editor

I have asked this question about a year ago and I am hoping there is some type of simple solution which will allow me achieve my objective. So here it goes: I often utilize shortcodes within the ...
11
votes
2answers
1k views

How to make a image-size selected by default in Media upload - WP v3.5

Bare with me. I want to have a custom image size selected by default in the Media upload popup page. In Wordpress v3.4.2 and prior, this elegant code worked fine: function ...
10
votes
4answers
902 views

Add image size if page template

I'm building a members website with WordPress Multisite. Is it possible to restrict how many images are being generated depending on the selected template? I have tried the following lines of code ...
10
votes
1answer
1k views

Is there a is_user_logged_in() for multisite?

Is there a is_user_logged_in() function for Wordpress MU / Multisite (3.0+) where I can add in the network site ID like is_user_logged_in(2) where 2 would be the site_id? Update: After a little ...
10
votes
3answers
4k views

Programatically add options to “add new” custom field dropdown

How can I add pre-defined options to the "add new" custom field dropdown? Here's two examples of automatically adding and showing new custom fields: WordPress: Adding Default Custom Fields on New ...
9
votes
5answers
6k views

How to use a custom post type archive as front page?

I'd like to use a custom post type archive as a site's front page, so that http://the_site.com/ is a custom post type archive displayed according to my archive-{post-type}.php file. Ideally I ...
9
votes
2answers
8k views

How to change default position of WP meta boxes?

Im wondering if there is a way to change the default position of Wordpresses meta boxes such as "featured image" for custom post types without having to drag them manually? Example:
9
votes
5answers
3k views

Does Wordpress have a “Form API”

I do most of my development in Drupal, however I am working on a Wordpress site and I need to make a form. Which got me thinking, is there a Form API for wordpress like there is Drupal? Is there a way ...
9
votes
1answer
3k views

Using classes instead of global functions in functions.php

In many themes I've seen (including TwentyEleven) and in the examples I've found online, when building the functions.php file for a theme all functionality is declared in a global scope. To clarify, ...
9
votes
2answers
12k views

Add multiple custom fields to the general settings page

What I would like to do is to add a few custom fields to the general settings. This is the code that Im using. It works allright but I just cant figure how to add more fields. I would like to create ...
9
votes
1answer
5k views

Mega Menu Walker

I'm trying to create a mega menu walker. Unfortunately, walkers completely escape my coding knowledge. I could really use some help getting it working. Here's the features I need: Wrap the ...
8
votes
3answers
2k views

How to change the case of all post titles to “Title Case”

I am helping my father with his WordPress website. It has over 1,700 posts with TITLES IN UPPERCASE. We'd like to change these to "Title Case" in the database (possibly using this PHP script). The ...
8
votes
4answers
3k views

How to load parent_theme functions.php before child_theme?

I got the problem that i have to load my parent theme's functions.php file before my child theme's functions.php file loads. This is needed for the setup & init procedure. I looked at the hooks ...
8
votes
2answers
9k views

Remove “Category:”, “Tag:”, “Author:” from the_archive_title

I have the following code in my theme's archive.php: <?php the_archive_title( '<h1 class="page-title">', '</h1>' ); ?> This gives me titles like "Category: Russia", "Tag: ...
8
votes
2answers
262 views

Displaying the number of updates available in the Admin area

I am having an issue finding out how to display the number of plugins/updates available to call somewhere else other than the admin header. I found the function wp_get_update_data should be what I ...
8
votes
1answer
2k views

What is the difference between wp_register_sidebar_widget and register_widget?

What's the difference between them and when should we use each one ? I'm using wp_register_sidebar_widget right now and it's working fine but I've seen a lot of tutorials online on how to create a ...
7
votes
4answers
18k views

How can you check if you are in a particular page in the WP Admin section? For example how can I check if I am in the Users > Your Profile page?

I'm building a plugin and I want to add bits of javascript in the admin head but only for certain admin pages. I don't mean pages as in a WordPress page that you create yourself but rather existing ...
7
votes
5answers
2k views

Is there any global functions.php file which works for any theme?

Is there some global kind of functions.php file that works for any theme? The problem is here: When I change a functions.php file in any theme, I need to take care of two changes: First, I need to ...
7
votes
2answers
11k views

Disable plugin / plugin action via theme

I have installed the Google Analyticator plugin on my site. I am also using the MobilePress plugin to serve up a theme designed for non-smart-phone mobile browsers. I have set up Google Analytics for ...
7
votes
2answers
166 views

Memorizing syntax

I hope the following question is acceptable here. I rely entirely on copy/paste for most WP functions, however I guess WP veterans don't. Is it important to know by heart the common WP syntax, and if ...
7
votes
3answers
2k views

remove_action on after_setup_theme not working from child theme

I am trying to remove a theme action for an elegant-themes theme using a child theme.. This works when I remove action after add_action code anywhere in the parent theme functions.php. However, it ...
7
votes
3answers
5k views

Excluding iPad from wp_is_mobile

I am eperiencing a very annoying problem. I built my website with media queries and is_mobile (thinking is_mobile would be the same as smaller screens. How foolish of me.) but after some testing ...
7
votes
1answer
266 views

How to redirect to post if search results only returns one post

I want to send visitors to my search.php after a search to display list of posts. If there is only one search result, user can directlyto the post in question(something like GOOGLE's I am Feeling ...
7
votes
2answers
470 views

Get rid of Wordpress category, tag and author archives?

I have searched the net with no success on what should be an easy thing. I have a highly customized blog with pages, sub pages and posts. While I rely heavily on the use of categories and tags I ...
7
votes
1answer
184 views

Shared functionality in plugins and themes

I recently started to develop plugins and themes and I found that I need to use several functions of on both. Sometime I think about to check if function / class exist before declared as said on this ...
7
votes
1answer
7k views

plugins_url vs plugin_dir_url

Im seeing WordPress plugins either use plugins_url or plugin_dir_url when creating constants to some of their folders. Is one better than the other? examples: define( 'MEMBERS_URI', trailingslashit( ...
7
votes
2answers
1k views

Use AJAX in shortcode

I have the following code to the shortcode to display a random quote. Question: how to make a button display a new random quote? I mean, that would hit the button and show you a new quote (without ...
7
votes
2answers
760 views

Remove Actions/Filters added via Anonymous Functions

That's a freaking bad practice I must say. Spent last two hours finding a solution to remove actions and filters added via Anonymous functions. This is the code used on a Parent Theme, and I need ...
7
votes
2answers
2k views

Remove “Insert from URL” link in Media upload - WP 3.5

How do I remove the Insert from URL link in the new Wordpress 3.5 Add Media popup page? In earlier versions of Wordpress, this worked fine: // removes URL tab in image upload for post function ...
7
votes
2answers
9k views

wp_enqueue_script was called incorrectly

Hello I don't know how but now I am getting this error Notice: wp_enqueue_style was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, ...
7
votes
3answers
681 views

Order posts (across the whole site) by metadata date

My custom 'Home' page is set to sort my custom posts via the custom date field with this (updated to be custom named) code in functions.php: // sort order for home page add_action('wp', ...
6
votes
6answers
5k views

Is it possible to rename a post format?

Since WP 3.1, it's been possible to use Tumblr-style post formats. I want to use the 'aside' option in a theme, but I want it to have a different title in the WP admin area. So, for example, when a ...
6
votes
4answers
396 views

Cleaning up WordPress to improve performance?

Looking over the current WordPress codebase it's clear that functions are over-used. My count is over 8,100 functions/methods are defined inside the WordPress codebase. That is terrible, and a ...
6
votes
4answers
6k views

Import Wordpress XML File from Within Functions.php

I am developing a theme which has a different method of adding in content and so, the default install of Wordpress won't show any content because of this. I was wondering if it is possible to ...
6
votes
1answer
2k views

Why does WordPress add 0 (zero) to an Ajax response?

Unless I end Ajax processing function by exit() or die(), the Ajax function receives desired and correct output but following by 0. Any idea why is that happening? Is that meant to be like that or ...