With this boilerplate plugin, creating new meta boxes for the WordPress backend becomes very easy. All you have to do is creating a new class implementing the meta box base class and write a function to render and one to save the meta box.
In the example-plugin folder you'll find a very simple plugin that uses the boilerplate. It uses the boilerplate plugin as a "helper plugin".
So to give it a try, just copy both folders into your wp-content/plugin directory and activate both of them, first the boilderplate, than the example plugin.
Just write a new PHP class which extends the Meta_Box base class and implements the Meta_Box_Interface.
This new new class needs to have two functions: render() and save(). In the constructor of this new class, you call the constructor of the parent class.
Here you can define the name, label, post type, position and priority of the new meta box.
Absolutely! You don't have to use it as a "helper plugin". The only thing you have to make sure is that the PHP files with the classes can be found.
The easiest way to achieve this is using the provided autoloader function from the Meta_Box_Boilerplate class.
Just copy this function into your theme or plugin, rename it to something unique like meta_box_boilerplate_autoload and hook it in like so:
spl_autoload_register( 'meta_box_boilerplate_autoload' );
You also have to copy the inc folder into you plugin or theme and copy all of your new meta box implementing classes into this folder.
As the function spl_autoload_register and namspaces are used, you need PHP 5.3 or greater, to use it this way.