How to add custom field. Modifying a plugin [closed]

Question

What i'm trying to achieve:

Replace {$post_title} in a review plugin that displays the Post's Title with a Custom Field. The Custom Field will be called thumb with URL to an image.

What I have

Code to display custom field

Here is the code that I use on my customized WP page, it displays the image from the custom field 'thumb'

<?php
  $custom_fields = get_post_custom($post_id); //Current post id
  $my_custom_field = $custom_fields['thumb']; //key name
  foreach ( $my_custom_field as $key => $value )
  echo "<img src='" . $value . "'>";
?>

Code in the plugin that calls the post title

$return .= "<td class='myrp_primary_alt_col myrp_name'><a class='post_name' href='" . get_permalink($post_id) . "'>{$post_title}</a></td>";

I'm not sure how to code in PHP so that the custom field can be displayed instead of post title.

Appreciate your responses to this.

Thanks.

Answer 1

So if I understand correctly, you are storing meta information for posts with meta_key "thumb", which you use somewhere in your website (theme or plugin or ..).

You would like to alter the output of a 3rd party plugin so it includes your meta, in the form of a thumbnail. Replacing {$post_title} with something of your own would to the trick but of course it'd be bad practice so you're looking for another solution.

I would think that any way around, it would be a bit of a hacky solution because you're dealing with output of another plugin. I'm not a Wordpress pro but I think the context in which this plugin outputs its content might be handy:

If the plugin's output is given in a place where you can simply override it, like in a list table, you might be able to do something like this:

add_filter('manage_upload_columns', 'my_callback');
function my_callback($columns) {
  // edit $columns, including something like 'my_column_override' => 'Hello'
}
add_action('manage_media_custom_column', 'my_column_overrider', 10, 2);
function my_column_overrider($colname, $post_id) {
  // spit out your own html
}

..or it might be in a meta box, in which case we might hack into it like so (not very sure, but see http://core.trac.wordpress.org/browser/tags/3.3.1/wp-admin/includes/template.php#L901):

$plugin_callback = $wp_meta_boxes[$page][$context][$priority][$id]['callback'];
$wp_meta_boxes[$page][$context][$priority][$id]['callback'] = 'my_callback';
function my_callback($post) {
  ob_start();
  call_user_func($plugin_callback, $post);
  $plugin_html = ob_get_clean();
  // spit out your own html
}