How to hide menubar and statusbar for 'read-only' documents?

Development
1

Hi,

I wanted to hide the menu and the statusbar altogether by these PostMessage calls:

iframe.contentWindow.postMessage({{
    MessageId:	'Hide_Menubar',
    SendTime:	Date.now()
 }}, '*');
iframe.contentWindow.postMessage({{
    MessageId:	'Hide_UI_Element',
    SendTime:	Date.now(),
    Values:		{{
       id: 'statusbar'
    }}
}}, '*');

As per docs I only could use PostMessage for sending messages after I saw App_LoadingStatus with Status=Document_Loaded. However, that status never is reached for ‘read-only’ documents which have:

["DisableExport"]			= isReadOnly,
["DisablePrint"]			= isReadOnly,
["HideSaveOption"]			= isReadOnly,
["UserCanWrite"]			= false,

… in their CheckFileInfo call. Only a Status=Initialized message is sent by CODE.

What am I missing?