Jetpack: add hashtags to tweets sent by Publicize

Jetpack’s Publicize module allows you to automatically publish your posts to your favorite Social Networks like Twitter or Facebook.

You can customize the message that is posted to Social Networks thanks to the small input field right above the Publish button:

But what if you wanted to automatically add details to each Publicized post? Since both Twitter and Facebook support hashtags, you could append the post tags after the post title, like so:

To do so, add the following code to a functionality plugin:

function jeherve_publicize_hashtags() {
	$post = get_post();
	if ( ! empty( $post ) ) {

		// Grab the tags of the post
		$post_tags = get_the_tags( $post->ID );

		// Append tags to custom message
		if ( ! empty( $post_tags ) ) {

			// Create list of tags with hashtags in front of them
			$hash_tags = '';
			foreach( $post_tags as $tag ) {
				$hash_tags .= ' #' . $tag->name;
			}

			// Create our custom message
			$custom_message = get_the_title() . ' ' . $hash_tags;
			update_post_meta( $post->ID, '_wpas_mess', $custom_message );
		}
	}
}

// Save that message
function jeherve_cust_pub_message_save() {
	add_action( 'save_post', 'jeherve_publicize_hashtags' );
}
add_action( 'publish_post', 'jeherve_cust_pub_message_save' );