There is a filter named default_content. It does exactly what the name says. 🙂
Example:
add_filter( 'default_content', 't5_preset_editor_content', 10, 2 );
/**
* Fills the default content for post type 'post' if it is not empty.
*
* @param string $content
* @param object $post
* @return string
*/
function t5_preset_editor_content( $content, $post )
{
if ( '' !== $content or 'post' !== $post->post_type )
{
return $content;
}
return 'This is the <em>default</em> content. You may customize it.';
}
As you can see, the post type is already available, so you could set different defaults for different post types.
Related filters are default_title and default_excerpt. They work the same way.
You can also send someone a link with parameters for content, post_title and excerpt:
http://example.com/wp-admin/post-new.php?content=hello+world%21&post_title=Sample+Title&excerpt=custom+excerpt
Output:
