As found here:
http://codex.wordpress.org/Function_Reference/add_meta_box
/**
* Calls the class on the post edit screen
*/
function call_someClass()
{
return new someClass();
}
if ( is_admin() )
add_action( 'load-post.php', 'call_someClass' );
/**
* The Class
*/
class someClass
{
const LANG = 'some_textdomain';
public function __construct()
{
add_action( 'add_meta_boxes', array( &$this, 'add_some_meta_box' ) );
}
/**
* Adds the meta box container
*/
public function add_some_meta_box()
{
add_meta_box(
'some_meta_box_name'
,__( 'Some Meta Box Headline', self::LANG )
,array( &$this, 'render_meta_box_content' )
,'post'
,'advanced'
,'high'
);
}
/**
* Render Meta Box content
*/
public function render_meta_box_content()
{
?>
<div class="mydiv">
<img src="https://wordpress.stackexchange.com/questions/47384/someImage.png" alt="someImage"/>
<script type="text/javascript">alert('hello world!');</script>
</div>
<?php
}
}