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filter is not described

wp_save_post_revision_post_has_changed filter-hook . WP 4.1.0

Filters whether a post has changed.

By default a revision is saved only if one of the revisioned fields has changed. This filter allows for additional checks to determine if there were changes.

Usage

add_filter( 'wp_save_post_revision_post_has_changed', 'filter_function_name_5610', 10, 3 );
function filter_function_name_5610( $post_has_changed, $last_revision, $post ){
	// filter...

	return $post_has_changed;
}
$post_has_changed(true/false)
Whether the post has changed.
$last_revision(WP_Post)
The last revision post object.
$post(WP_Post)
The post object.

Where the hook is called

wp_save_post_revision()
wp_save_post_revision_post_has_changed
wp-includes/revision.php 177
$post_has_changed = (bool) apply_filters( 'wp_save_post_revision_post_has_changed', $post_has_changed, $last_revision, $post );

Where the hook is used (in WP core)

wp-includes/class-wp-customize-manager.php 2860
add_filter( 'wp_save_post_revision_post_has_changed', array( $this, '_filter_revision_post_has_changed' ), 5, 3 );
wp-includes/class-wp-customize-manager.php 2900
remove_filter( 'wp_save_post_revision_post_has_changed', array( $this, '_filter_revision_post_has_changed' ) );