Yesterday, I asked by a friend to publish his post at Blogazinist. I published it then, and realized that the post was not the final yet. He wanted to edit it, so I pending that post again. And had been doing those activity for many times.
By default, we set registered user on Blogazinist as a contributor. After reading a while at WordPress Codex about User Roles and Capabilities, I knew that contributor can edit their posts, but not after it’s published. Then I scrolling down edit_published_posts capability. Then I thought to add that capability to contributor role.
We all knew, WordPress gives easy way to modify its core functions by hooking to that function. So, to achieve that, I hooked to admin_init function. Also using get_role function to get contributor role and add a new capability on it.
function contributor_edit_published() {
$contributor = get_role('contributor');
$contributor->add_cap('edit_published_posts');
}
add_action('admin_init', 'contributor_edit_published');
By now, Blogazinist’s contributor could edit their published posts. 
A friend that asked you to publish his post is me :p
Okay, I’ll post something on blogazinist next time
Actually its Zhinto :p
I was wrong :S
Cool. So now I can edit my old posts in Blogazinist.
Wow, coool