wp_installing ( $is_installing = null )
- (bool) is_installing Optional. True to set WP into Installing mode, false to turn Installing mode off. Omit this parameter if you only want to fetch the current status.
- (bool) True if WP is installing, otherwise false. When a `$is_installing` is passed, the function will report whether WP was in installing mode prior to the change to `$is_installing`.
- Introduced in WordPress: 4.4.0
- Deprecated in WordPress: —
Check or set whether WordPress is in "installation" mode.If the `WP_INSTALLING` constant is defined during the bootstrap, `wp_installing()` will default to `true`.