When you activate a new wordpress theme in the dashboard of appearance/themes, switch_theme is called with the to-be-switched theme as the parameter. switch_theme saves the $$sidebars_widgets in the theme_mod-currenttheme option, […]
If you log in WordPress backend and click Appearance/Themes menu, you will see all installed themes. If you put a theme directory under wp-content/themes/, you will see the new theme […]
If your use the returned data of an ajax call, you will find there is an unexpected extra 0 in the data. For example, if your action function is: function […]
Ajax is used by wordpress for communication between browser and server. For example, after you login wordpress dashboard, drag a widget onto a sidebar, fill some settings and click the […]
A function in cron.php wp_cron() is hooked to init action to check crons(got from the ‘cron’ option in the wp_options table). if it sees there is a cron that should […]
WordPress action order is an important thing to consider when you call add_action to add your hook function to a specific action. Here is the order for some important actions. […]
Today it turns out I got a big misunderstanding of HTML checkbox. I thought <input type=”checkbox” value=”1″> will check the box, while <input type=”checkbox” value=”0″> will uncheck the box. Unfortunately, […]
WordPress url rewrite has nothing to do with .htaccess file. WordPress url rewrite is done in wp() in wp-blog-header.php. wp() eventually calls parse_request in class WP, where a set of […]
$_SERVER[‘REQUEST_URI’] is what you type in your address bar of your browse(no protocol and host part). $_SERVER[‘PHP_SELF’] is the url of the first file loaded(no protocol and host part) with […]
First, we should know that isset and empty are php language construct while is_null is a function. So you won’t get an E_NOTICE when passing undefined variable to isset or […]