There are many ways to setup a file system hierarchy. The rules of any given system must be applied carefully if security of data is important.

The basic rules for users in a role with 'access webfm' rights:

• The role root directory defines the domain and all subdirectories that are accessible to the user.
• The user cannot navigate above the role root directory.
• Only files in the webfm_file table are accessible. Files uploaded by the user are owned by the user and are automatically in the database. Only module admins can view/operate on files not in the database.
• The user has full control over files that he/she owns that stay within an accessible role root domain. File permissions can be locked down so that only the owner/admins can see or operate on a file. File permissions can be opened up so that anyone within the role can view or operate on the file.
• Users with 'access webfm' rights cannot create/delete/move/rename directories. Only module administrators (users with 'administer webfm' permission or #1 user) can control the directory structure.

Roles with 'access webfm' rights can be subsets of other roles with 'access webfm' rights or they can be exclusive. Users can be members of multiple roles and will consequently have a separate left-hand tree for each unique root directory (roles can even share the same root directory).

It is difficult to foresee how diverse users of the module will choose to set up their systems but the following simple examples are typical arrangements. Both examples presume that the drupal file-system directory is set to 'files', the WebFM module is installed and the 'WebFM root directory' is set to 'webfm'.

Example 1

The site requires 1 class of privileged users (A) to administer the file system and 2 classes of WebFM users (B & C) with access to file resources. Both roles will be able to upload files. Some WebFM users are members of both B & C while others are members of only one. The 'Default File Permissions' are set so that uploaded files are initially accessible only by the file owner and admins.

• A site administrator will create 3 the roles A, B and C. Role A will have the 'administer webfm' permission set in .../admin/user/access. B & C will have the 'access webfm' and the 'webfm upload' permission set.
• WebFM settings will now have a fieldset for roles B & C where the root directory for each role is set. The root of B is set to 'B' which automatically creates the 'files/webfm/B' directory. The root of C is set to 'C' which creates the directory 'files/webfm/C'. A user who is a member of only one of B or C will see a single left-hand directory tree that contains their domain. They will have no access to files within the other role domain. Users who are members of both B & C will have two left-hand directory trees and have the ability to move files they own or control between the two domains.

  Role A's root directory is the 'WebFM root directory' and thus A users see only a single left-hand tree of the entire module file-sys.

• In WebFM settings, the 'Default File Permissions' are configured with all checkboxes unset. This combination of default file permissions means that files that are uploaded will initially only be viewable by the B or C user doing the upload (owner) and by A users. Individual file permissions are editable by the file owner or A user to permit other users to view/attach/modify the file. One consequence of granting the permission 'Role Full Access' is that a non-admin user with a single domain could lose contact with their own file if a dual domain non-admin user moves it to the other domain.

Example 2

The site requires 1 class of privileged users (A) to administer the file system and 2 classes of users (B & C) with access to file resources. C is determined to be a subset of B such that B can access its own files as well as those of C. C will not be able to upload files to the browser but will only be able to view/download or attach files to nodes. B will be able to upload files.

• A site administrator will create 3 the roles A, B and C. Role A will have the 'administer webfm' permission set in .../admin/user/access. B & C will have the 'access webfm' permission set. B will also have the 'webfm upload' permission set.
• WebFM settings will now have a fieldset for roles B & C where the root directory for each role is set. First the root of B is set to 'B' which automatically creates the 'files/webfm/B' directory. Next the root of C is set to 'B/C' which creates the directory 'files/webfm/B/C'. Since C is a sub-dir of B, role B will have access to C but C will not be able to navigate above its root to see B's files. The left-hand directory tree will appear different for B & C. B's tree will start at 'B' and have a 'C' sub-directory (and potentially other sub-directories as set up by A). C's tree is a subset of B's tree.

  Role A's root directory is the 'WebFM root directory'.

• In WebFM settings, the 'Default File Permissions' are configured with 'Role View Access' and 'Role Attach Access' set. This combination of file permissions means that files that a B user uploads/moves into the C realm will by default be viewable by C and be attachable to nodes that C creates. A B file owner can manually modify the file permissions of each individual file to hide it or prevent it from being attached to content by a C user. Likewise the file permissions can be opened so that a C user can edit file attributes or move the file into another sub-directory of C.

In the above examples the site administrator may simply create the roles/access rules and then let an A user configure WebFM for B & C.