plugin-development - Read For Learn

How to remove duplicate sub-menu name for top level menu items in a plugin?

If you dont want ‘TopLevel’ menu to represent a custom page you can use: add_menu_page( ‘TopLevel’, ‘TopLevel’, ‘MENU_CAP_LVL’, ‘MENU_SLUG’, ‘MENU_CB’ ); add_submenu_page( ‘MENU_SLUG’, ‘SubMenu’, ‘SubMenu’, ‘MENU_CAP_LVL’, ‘SUB_MENU_SLUG’, ‘SUB_MENU_CB’ ); add_submenu_page( ‘MENU_SLUG’, ‘SubMenu-A’, ‘SubMenu-A’, ‘MENU_CAP_LVL’, ‘SUB_MENU_A_SLUG’, ‘SUB_MENU_A_CB’ ); remove_submenu_page(‘MENU_SLUG’,’MENU_SLUG’); In this way click on “TopMenu” will forward to the 1st “SubMenu” and prevent “TopLevel” from being … Read more

How would I create a plugin for my shortcodes?

Code in functions.php and plugins works in almost exactly same way (except than stage at which it is loaded and some plugin-specific hooks). Basically you just take your code out of functions.php, place it in plugin and it still works. It is good practice to use naming conventions and checking for functions definitions so it … Read more

What is the recommended way to create plugin administration forms?

I personally just add a menu link and in the function for it handle the form. With $_SERVER[‘REQUEST_URI’] as the action. Example below. add_action(“admin_menu”, “menu” ); function menu(){ add_menu_page(‘Test form’, ‘Test form’, ‘manage_options’, ‘show_form’ ); } function show_form(){ if ( $_SERVER[“REQUEST_METHOD”] == “POST” ){ print “do stuff”; } else { ?><form method=”post” action=”<?php echo $_SERVER[‘REQUEST_URI’]; … Read more

How to properly sanitize strings for update_option()

Try esc_html( $string ) (Codex ref), which among other things encodes single- and double-quotes. For further reference, see the Data Validation entry in the Codex.

Advice on naming files for a plugin

There’s certainly no need to name plugin files with prefixes (although some plugin authors like to do this). I suspect the advice you read was referring to functions within your plugin files. Structuring you plugin folders as you suggest (using a class folder) is fine. See this link for more information on writing plugins: http://codex.wordpress.org/Writing_a_Plugin … Read more

How does WordPress handle MySQL row lock errors?

Strictly from a MySQL Point-of-View SHORT VERSION MyISAM Storage Engine Table locks Writes are first come, first serve Reads slow down writes from initiating InnoDB Storage Engine Row locks Transactions (non blocking) Deadlock may occur when updating indexes LONG VERSION If the underlying tables use the MyISAM Storage Engine, row locks are not possible. Each … Read more

Redirect to settings page after install

Register an activation hook and then redirect the user’s browser when you’re done installing your plugin. function myplugin_activate() { // TODO: Install your plugin here. // I don’t know of any other redirect function, so this’ll have to do. wp_redirect(admin_url(‘options-general.php?page=myplugin_settings’)); // You could use a header(sprintf(‘Location: %s’, admin_url(…)); here instead too. } register_activation_hook(__FILE__, ‘myplugin_activate’);

Problems with autoloading classes via sp_autoload_register / maybe interfering WP-specific autoloader

There is no built-in autoloader in WordPress. But other plugins or a theme might have registered an autoloader, and depending on the order of execution these are called earlier or later than yours. Update 21. 08. 2014 This answer is no longer what I would recommend. Do use an autoloader if you need one. The … Read more

PHPUnit testing WordPress Plugin

The reason the WordPress test bootstrap is loaded at the end is precisely because it loads WordPress: // Load WordPress require_once ABSPATH . ‘/wp-settings.php’; If you don’t hook your function to load your plugin to ‘muplugins_loaded’ before including the bootstrap, your plugin won’t be loaded with WordPress. In most cases that will mean that your … Read more

When is wp_loaded initiated only with admin or only when user enters the site or both?

wp_loaded fires for both the front-end and admin section of the site. This action hook is fired once WordPress, all plugins, and the theme are fully loaded and instantiated. Since you’re checking for plugin updates, it might be best to hook into admin_init instead of wp_loaded — assuming you want to know if a user … Read more

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