how to execute some code after a post is published in Wordpress [duplicate]

Question

I have written a simple code to do something after a post is updated or published (its related to the varnish purge). I put my code inside post.php file. Everything was just fine before the latest update (4.8.3), after that all my codes were vanished!! of course it is a normal behavior because the post.php file has been replaced with a new one from update patch. I want to know how can I execute some code after a post is updated or published and my codes do not disappear after a Wordpress update? I don't want to use plugins too :D. Thank you.

Answer 1

You're looking for the save_post action. This allows you to add a function when a post is saved (updated).

You can hook into it like this:

function your_save_post_function( $post_id ) {
}

add_action( 'save_post', 'your_save_post_function' );

Remember to not change WordPress Core files, as these will be overwritten when WordPress is updated. You can put this code in your functions.php file, or anywhere else in your theme folder.

Answer 2

<?php
add_action( 'save_post', 'varnish_purge' );
function varnish_purge()
{
 // code here
} 

Answer 3

You can replace publish_{post} , where {post} is any wordpress post type.

function post_published_notification( $ID, $post ) {
    $author = $post->post_author; /* Post author ID. */
    $name = get_the_author_meta( 'display_name', $author );
    $email = get_the_author_meta( 'user_email', $author );
    $title = $post->post_title;
    $permalink = get_permalink( $ID );
    $edit = get_edit_post_link( $ID, '' );
    $to[] = sprintf( '%s <%s>', $name, $email );
    $subject = sprintf( 'Published: %s', $title );
    $message = sprintf ('Congratulations, %s! Your article “%s” has been published.' . "\n\n", $name, $title );
    $message .= sprintf( 'View: %s', $permalink );
    $headers[] = '';
    wp_mail( $to, $subject, $message, $headers );
}
add_action( 'publish_post', 'post_published_notification', 10, 2 );