In my projects I do it like that PHP function foo() { echo ‘bar’; } add_action(‘wp_ajax_foo’, ‘foo’ ); // executed when logged in add_action(‘wp_ajax_nopriv_foo’, ‘foo’ ); // executed when logged out Javascript data = { action: ‘foo’, avalue: ‘some value’, ‘anothervalue’: ‘another value’ }; jQuery.post(ajaxurl, data, function(response){ alert(response); });
There is the filter ‘pre_update_option_’ . $option. You have to know the option name. Options can be updated from front-end too, so WordPress doesn’t make a difference here. Then there is an action: ‘update_option’, you get the arguments $option, $oldvalue and $_newvalue. Finally, if the update went successful, you get two further actions: do_action( “update_option_{$option}”, … Read more
If you look at the code for wp-login.php both the login case and the default case run wp_signon(). The reason, so it seems to me, is to manage cases where a user already has a valid cookie for the site. So I don’t think there is a hook that fires only upon login, but it … Read more
Is there any hook that fires once the image is uploaded and the image sizes generated? wp_handle_upload fires after the image is uploaded. After the follow-up question, I discovered that images would not be sized at this point. add_filter( ‘wp_handle_upload’ ‘wpse_256351_upload’, 10, 2 ); function wpse_256351_upload( $upload, $context ) { //* Do something interesting return … Read more
The reason the code posted is not working is that $post is not referencing the global $post variable, which is the goal here. Using get_the_ID() is a good way of accessing the ID associated with the current post. That’s how I’d suggest doing it, but there are other ways too: add_action ( ‘wp_head’, ‘hook_inHeader’ ); … Read more
It is possible for action hooks to be provided without being used, which is what’s happening here. woocommerce_before_checkout_process and woocommerce_checkout_process are hooks provided by WooCommerce, but WooCommerce does not itself attach callback functions to either of these hooks. They are provided to allow plugins and themes to run code at the time that the respective … Read more
There are no limits and no performance penalties. To understand why, you need to understand how all hooks are stored in the WP ecosystem. First of all you need to understand where all hooks are stored and how they do it. All hooks for filters and actions are stored in global variable called wp_filter, yes … Read more
Actions do things. Filters modify things. You do stuff in an action, whereas if you apply a filter, you do not expect any events or actions to occur, other than the modification of the value you’re filtering. e.g. It’s not okay to send an email or save a DB value in a filter, but it … Read more
all is just a string the WordPress developers picked to behave differently than any other hook. When you attach to all, your callback will fire for all other hooks. I wouldn’t spend too much time looking at the source of do_action, just know that: add_action( ‘x’, ‘whatever’ ) will mean whatever fires for do_action( ‘x’ … Read more
You need a second form with admin_url(‘admin-post.php’) as form action. Then you can hook into admin_post_custom_action to execute your action. Sample code: add_action( ‘admin_post_wpse_79898’, ‘wpse_79898_test’ ); function wpse_79898_test() { if ( isset ( $_GET[‘test’] ) ) echo esc_html( $_GET[‘test’] ); die( __FUNCTION__ ); } In your settings page: <form action=”<?php echo admin_url( ‘admin-post.php’ ); ?>”> … Read more