Automatically title a post based on its type and category

automatically-title-post.php

<?php
/*
Plugin Name: Automatically Title Post
Description: Automatically title post based on post type and taxonomy.
Version: 1.0.0.RC.1
Author: Nick Ohrn of Plugin-Developer.com
Author URI: http://plugin-developer.com/
*/

function automatically_title_post($post_id, $post, $update) {
	$desired_taxonomy = 'category';
	$desired_type = 'post';

	if($desired_type === $post->post_type) {
		$post_type_object = get_post_type_object($post->post_type);
		$terms = wp_get_object_terms($post_id, array($desired_taxonomy));

		$post_title_parts = array();

		$post_title_parts[] = $post_type_object->labels->singular_name;
		$post_title_parts[] = empty($terms) ? '' : array_shift($terms)->name;

		$post_title = implode(' - ', array_filter(array_map('trim', $post_title_parts)));
		$post_name = sanitize_title($post_title, $post_id);

		global $wpdb;
		$wpdb->update($wpdb->posts, array('post_name' => $post_name, 'post_title' => $post_title), array('ID' => $post_id));
	}
}
add_action('wp_insert_post', 'automatically_title_post', 11, 3);