How to get Openbox as kde's window manager

Testing

Installing the openbox.

Making a new user.

Log in as the new user.

The KDE Menu is empty.

Trying to fix

Running the kbuildsycoca4 to rebuild the system configuration cache.

:~$ kbuildsycoca4 --help
Usage: kbuildsycoca4 [Qt-options] [KDE-options] [options] 

Rebuilds the system configuration cache.

Generic options:
  --help                    Show help about options
  --help-qt                 Show Qt specific options
  --help-kde                Show KDE specific options
  --help-all                Show all options
  --author                  Show author information
  -v, --version             Show version information
  --license                 Show license information
  --                        End of options

Options:
  --nosignal                Do not signal applications to update
  --noincremental           Disable incremental update, re-read everything
  --checkstamps             Check file timestamps
  --nocheckfiles            Disable checking files (dangerous)
  --global                  Create global database
  --menutest                Perform menu generation test run only
  --track <menu-id>         Track menu id for debug purposes

There is an error - missing files.

Starting the Dolphin file manager with the root rights (kdesudo dolphin).

Browsing to the /etc/xdg/menus/. There is the kde4-applications.menu but not the applications.menu.

Making a softlink / symlink from the applications.menu to the kde4-applications.menu (KDE drag&drop menu "link here").

Running the command:

kbuildsycoca4 --noincremental

again...

The KDE menu is now populated with the available applications.