_wp_post_revision_field_(field) │ filter-hook │ WP 3.6.0

Contextually filter a post revision field.

The dynamic portion of the hook name, $field, corresponds to a name of a field of the revision object.

Possible hook names include:

• _wp_post_revision_field_post_title
• _wp_post_revision_field_post_content
• _wp_post_revision_field_post_excerpt

Usage

add_filter( '_wp_post_revision_field_(field)', 'wp_kama__wp_post_revision_field_filter', 10, 4 );

/**
 * Function for `_wp_post_revision_field_(field)` filter-hook.
 * 
 * @param string  $revision_field The current revision field to compare to or from.
 * @param string  $field          The current revision field.
 * @param WP_Post $compare_from   The revision post object to compare to or from.
 * @param string  $context        The context of whether the current revision is the old or the new one. Either 'to' or 'from'.
 *
 * @return string
 */
function wp_kama__wp_post_revision_field_filter( $revision_field, $field, $compare_from, $context ){

	// filter...
	return $revision_field;
}

$revision_field(string)

The current revision field to compare to or from.

$field(string)

The current revision field.

$compare_from(WP_Post)

The revision post object to compare to or from.

$context(string)

The context of whether the current revision is the old or the new one. Either 'to' or 'from'.

Changelog

Where the hook is called

$content_from = $compare_from ? apply_filters( "_wp_post_revision_field_{$field}", $compare_from->$field, $field, $compare_from, 'from' ) : '';

$content_to = apply_filters( "_wp_post_revision_field_{$field}", $compare_to->$field, $field, $compare_to, 'to' );

Where the hook is used in WordPress

add_filter( '_wp_post_revision_field_footnotes', 'wp_get_footnotes_from_revision', 10, 3 );