Casey Bisson

This is a convenience class and collection of methods to make creating new custom post types with their own metaboxes easy.
The general idea is to define a function that’s hooked to the <code>register_post_types</code> action. The function defines a class for your post type that extends the <code>GO_Cpt</code> class. This follows a design pattern established by the modern widgets API (as introduced in WP 2.8) https://codex.wordpress.org/Widgets_API#Developing_Widgets .
The result is a new custom post type and much easier creation and updating of custom meta associated with that post type. You’ll also have a convenient object you can use to access the metadata associated with each post.
<pre><code>function my_customposttype() { class My_CustomPostType extends GO_Cpt { function __construct() { // execute the parent constructor with the name 
 // and definition for the custom post type parent::__construct( $post_type_name , $post_type_definition ); } function metabox( $post , $meta ) { // print out the form here // 
 // this method is optional, only use it if you want to 
 // add a metabox to your custom post type } function update( $new_meta , $old_meta ) { // sanitize and validate the metadata // then return $meta so it can be saved // // this method is required if a 
 // metabox() method is included } } global $my_customposttype; $my_customposttype = new My_CustomPostType; } // hook that function to the register_post_types action add_action( 'register_post_types' , 'my_customposttype' ); </code></pre>
Backstory: defining the post type class inside the function avoids issues with loading order and fatal errors resulting from attempting to extend a class that might not exist yet. Isn’t PHP awesome?
See the included hello world example: https://plugins.trac.wordpress.org/browser/go-cptfactory/trunk/example-helloworld-cpt.php
To access the meta associated with a post, you can call <code>$my_customposttype->get_meta( $post_id );</code>
You can easily add a method and hook to filter <code>the_content</code> or <code>the_excerpt</code> to insert custom values that may have been entered in the post meta. Simply add <code>add_filter( 'the_content' , array( $this , 'the_content' ));</code> in the <code>__construct()</code> and then define another method in the <code>My_CustomPostType</code> class such as:`
<pre><code> function the_content( $content ) { 
 $meta_print = print_r( $this->get_meta( get_the_ID() ) , TRUE ); 
 return $meta_print . $content 
 } </code></pre>
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GigaOM Custom Post Type Factory

Makes defining custom post types as easy as creating a widget. Includes example code to get you started.

Electric Studio

javorszky

Adds an expiry date and time to posts, pages, or custom post types in which the post becomes a draft.
<ul>
<li>Supports custom post types</li>
<li>Allows admin to choose which post types can expire</li>
<li>Sets expired posts to drafts rather than deleting them</li>
<li>To show an expiry date on the frontend, use shortcode [expirydate] else function es_ape_exp_date()</li>
</ul>

Electric Studio Auto Post Expire

Adds an expiry date and time to posts, pages, or custom post types after which the post becomes expired.

GigaOM Custom Post Type Factory vs Electric Studio Auto Post Expire