In LibreOffice Writer, Impress, and Draw, only one user at a time can open any document for writing. In Calc, many users can open the same spreadsheet for writing at the same time.
In LibreOffice Calc, document sharing allows simultaneous write access for many users. Every user who wants to collaborate should enter a name on the LibreOffice - Preferences Tools - Options - LibreOffice - User Data tab page.
Some commands are not available (grayed out) when change tracking or document sharing is activated. For a new spreadsheet you cannot apply or insert the grayed out elements.
User A creates a new spreadsheet document. The following conditions can apply:
The user does not want to share the spreadsheet for collaboration.
User A opens, edits, and saves the document as described above for Writer, Impress, and Draw document.
The user wants to share the document for collaboration.
The user choosesto activate the collaboration features for this document. A dialog opens where the user can choose to enable or disable sharing. If the user enables sharing, the document will be saved in shared mode, which is also shown on the title bar.
Thecommand can be used to switch the mode for the current document from unshared mode to shared mode. If you want to use a shared document in unshared mode, you would save the shared document using another name or path. This creates a copy of the spreadsheet that is not shared.
User A opens a spreadsheet document. The following conditions can apply:
The spreadsheet document is not in shared mode.
The user can open, edit, and save the document as described above for Writer, Impress, and Draw documents.
The spreadsheet document is in shared mode.
The user sees a message that the document is in shared mode and that some features are not available in this mode. The user can disable this message for the future. After clicking OK, the document is opened in shared mode.
User A saves a shared document. The following conditions can apply:
The document was not modified and saved by another user since user A opened the document.
The document is saved.
The document was modified and saved by another user since user A opened the document.
If the changes do not conflict, the document is saved.
If the changes conflict, the Resolve Conflicts dialog will be shown. User A must decide for the conflicts which version to keep, "Keep Mine" or "Keep Other". When all conflicts are resolved, the document is saved. While user A resolves the conflicts, no other user is able to save the shared document.
Another user tries to save the shared document and resolves conflicts in this moment.
User A sees a message that a merge-in is in progress. User A can choose to cancel the save command for now, or retry saving some time later.
When a user successfully saves a shared spreadsheet, the document will be reloaded after the save command, so that the spreadsheet shows the latest version of all changes that got saved by all users. A message shows that "foreign changes have been added" when another user did change some contents.
For all modules Writer, Impress, Draw, and for Calc when document sharing is not enabled, a file locking is possible. This file locking is available even when accessing the same document from different operating systems:
User A opens a document. The following conditions can apply:
The document is not locked by any other user.
This document will be opened for read and write access by user A. The document will be locked for other users until user A closes the document.
The document is marked as "read-only" by the file system.
This document will be opened in read-only mode. Editing is not allowed. User A can save the document using another document name or another path. User A can edit this copy.
The document is locked by another user.
User A sees a dialog that tells the user the document is locked. The dialog offers to open the document in read-only mode, or to open a copy for editing, or to cancel the Open command.
Some conditions must be met on operating systems with a user permission management.
The shared file needs to reside in a location which is accessible by all collaborators.
The file permissions for both the document and the corresponding lock file need to be set so that all collaborators can create, delete, and change the files.
Write access also enables other users to (accidentally or deliberately) delete or change a file.