Does WordPress provide an API for scheduling posts?

Question

I'm a database noob so I'm a little bit clueless as to how to make a scheduled post via a plugin. Basically, does WP provide a reference API that would allow a plugin to create a scheduled post, like a user can do through the dashboard?

Answer 1

There isn't really an API for it, because from usage perspective it is quite simple.

If data passed to wp_insert_post() has publish or future value in post_status field and date in the future then it is inserted in database with that date and future in post_status. Effectively it is already considered scheduled.

However something would need to happen to make that post published on that date, so this sets in motion several more pieces of code:

1. When wp_insert_post() is done it calls wp_transition_post_status().

2. Which executes several hooks, including "{$new_status}_{$post->post_type}" which unwraps to something like future_post.

3. When post type is registered by register_post_type() it adds _future_post_hook() function to 'future_' . $post_type hook and so it executes.
4. That function creates single WP-Cron schedule at the date of post, post's ID in data and name of publish_future_post.
5. That schedule name has check_and_publish_future_post() function hooked to it, that on run checks if post by that ID is scheduled and up to be live and if so flips its status to published using wp_publish_post().

So the simplest way to create scheduled post is to just follow native mechanics and create it with wp_insert_post(), while passing future date.

Answer 2

If you are using the xmlrpc way of posting articles, then you have the option of not posting your articles immediately.

    //$client = new IXR_Client('http://localhost/giftanexperience/xmlrpc.php');
    $client = new IXR_Client('<domain>/xmlrpc.php');

    //if (!$client->query('wp.getCategories','', <username>,<password>)) {
    //      die('An error occurred - '.$client->getErrorCode().":".$client->getErrorMessage());
    //}
    echo $client->getResponse();

    $content['title'] = $title;
    $content['description'] = $description;
    $content['categories'] = $categories;
    $content['mt_keywords'] = $tags;

    if (!$client->query('metaWeblog.newPost','', <username>,<password>, $content, true)) {
            die('An error occurred - '.$client->getErrorCode().":".$client->getErrorMessage());
    }
    echo $client->getResponse() . "\n" ;    //with Wordpress, will report the ID of the new post

Here you can substitute true with false to not publish your article.

For a detailed sample, you can look up: http://www.home-working.info/index.php/creating-a-wordpress-website-via-xml-rpc-using-affiliate-data-feeds/

Hope this helps.