[wp-trac] [WordPress Trac] #19691: Cannot modify admin messages for /wp-admin/edit.php

[WordPress Trac]

#19691: Cannot modify admin messages for /wp-admin/edit.php
--------------------------+------------------------------------------------
 Reporter:  mikeschinkel  |      Owner:
     Type:  enhancement   |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:                |    Version:  3.3
  Administration          |   Keywords:  dev-feedback has-patch 2nd-opinion
 Severity:  normal        |
--------------------------+------------------------------------------------
 The admin console messages output on line `264` of WordPress 3.3's file
 `/wp-admin/edit.php` are not filterable. This causes problems when added
 row actions need to HTTP GET from to WordPress to modify a post and then
 display an appropriate message complete with a revert link ''(like the
 "Trash" link does.)''

 An example use-case could be for a custom post type used for both quotes
 and invoices where a row action might be ''"Convert Quote to Invoice"''
 where you'd want a message and link displayed at the top of the admin
 after similar to this:

 - ''Quote #{$post_id} converted to Invoice. __Revert__''

 Currently the only way to accomplish this is to pick hooks before and
 after the messages are output and use PHP's output buffering;  clearly not
 a ''"best practice"'' approach.

 In order to address this I'm proposing an '''`'admin_messages'`''' filter
 hook to run just before the messages are output:

 {{{
 $messages = apply_filters( 'admin_messages', $messages );
 }}}

 However, since messages are output in numerous locations in the WordPress
 admin it seemed best to add the hook in every location where messages are
 output, which is what my patch does.  Thus a hook can look at `$pagenow`
 or `get_current_screen()` to decide it is needs to do anything.

 Also while searching for places in the admin code that echo messages I
 found `$messages` are sometimes an array of HTML where the entire array is
 echoed and other times the $messages are an array with an index passed via
 `$_GET` and only one message will be displayed. For those cases I created
 another hook '''`'admin_message'`''' ''(note that this hook name is
 singular)'':

 {{{
 $message = apply_filters( 'admin_message', $message, $messages,
 $_GET['message'] );
 }}}

 I really only found a specific need for `/wp-admin/edit.php` today, but it
 seemed that it would be better for consistency if all messages were made
 hook filterable. That's why I created a larger patch when all my use-case
 needs is one new line.

 Looking forward to your feedback.

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/19691>
WordPress Trac <http://core.trac.wordpress.org/>
WordPress blogging software