$subpage
$subpage : string
Identifies submenu entry in the Admin sidebar, e.g., Media/Assistant in Media
Class CPAC Storage Model MLA (Media Library Assistant) supports the Admin Columns plugin
manage_value(string $content, object $item, string $column_name) : string
Return the content of an Admin Columns custom column
string | $content | Current column content (empty string) |
object | $item | Current Media Library item |
string | $column_name | Current column slug |
Column value or NULL if not an Admin Columns custom column