[wp-trac] [WordPress Trac] #18713: No hooks available to "calculate" a post_title when only custom metaboxes in use

[WordPress Trac]

#18713: No hooks available to "calculate" a post_title when only custom metaboxes
in use
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 Reporter:  mikeschinkel                        |       Owner:
     Type:  enhancement                         |      Status:  new
 Priority:  normal                              |   Milestone:  Awaiting
Component:  Post Types                          |  Review
 Severity:  normal                              |     Version:  3.2.1
 Keywords:  has-patch dev-feedback 2nd-opinion  |  Resolution:
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Comment (by mikeschinkel):

 @prettyboymp - The `santize_post_field()` is an interesting suggestion.
 Here's what I found after trying it:

 Yes it is possible to provide a value for `post_title` using the
 `'pre_post_title'` hook before WordPress punts on an empty value. However
 when used in the needed`'db'` context that hook only gets passed the
 $value and not `$post_id` or any other needed info. This is ironic because
 the alternate hook `'edit_post_field'` used in the `'edit'` context is
 passed both `$value` and `$post_id`.  So for it to be a solution we'd
 minimally need to add `$post_id` as a 2nd parameter to the
 `'pre_post_title'` hook.  Here's the `sanitize_post_fields()` function so
 you can see what I'm talking about:

 {{{
 function sanitize_post_field($field, $value, $post_id, $context) {
         $int_fields = array('ID', 'post_parent', 'menu_order');
         if ( in_array($field, $int_fields) )
                 $value = (int) $value;

         // Fields which contain arrays of ints.
         $array_int_fields = array( 'ancestors' );
         if ( in_array($field, $array_int_fields) ) {
                 $value = array_map( 'absint', $value);
                 return $value;
         }

         if ( 'raw' == $context )
                 return $value;

         $prefixed = false;
         if ( false !== strpos($field, 'post_') ) {
                 $prefixed = true;
                 $field_no_prefix = str_replace('post_', '', $field);
         }

         if ( 'edit' == $context ) {
                 $format_to_edit = array('post_content', 'post_excerpt',
 'post_title', 'post_password');

                 if ( $prefixed ) {
                         $value = apply_filters("edit_{$field}", $value,
 $post_id);
                         // Old school
                         $value =
 apply_filters("{$field_no_prefix}_edit_pre", $value, $post_id);
                 } else {
                         $value = apply_filters("edit_post_{$field}",
 $value, $post_id);
                 }

                 if ( in_array($field, $format_to_edit) ) {
                         if ( 'post_content' == $field )
                                 $value = format_to_edit($value,
 user_can_richedit());
                         else
                                 $value = format_to_edit($value);
                 } else {
                         $value = esc_attr($value);
                 }
         } else if ( 'db' == $context ) {
                 if ( $prefixed ) {
                         $value = apply_filters("pre_{$field}", $value);
                         $value =
 apply_filters("{$field_no_prefix}_save_pre", $value);
                 } else {
                         $value = apply_filters("pre_post_{$field}",
 $value);
                         $value = apply_filters("{$field}_pre", $value);
                 }
         } else {
                 // Use display filters by default.
                 if ( $prefixed )
                         $value = apply_filters($field, $value, $post_id,
 $context);
                 else
                         $value = apply_filters("post_{$field}", $value,
 $post_id, $context);
         }

         if ( 'attribute' == $context )
                 $value = esc_attr($value);
         else if ( 'js' == $context )
                 $value = esc_js($value);

         return $value;
 }
 }}}

 However `sanitize_post_field()` is called in at least eight (8) places
 within WordPress core with six (6) different contexts, and leveraging it
 to set a default value for `post_title` or `post_content` is likely to
 result in lots of unintended consequences that would take a long time to
 identify and then correct.  So I think a hook that is much more limited in
 scope would have less potential for inadvertent bugs.

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/18713#comment:14>
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