I also need an FTP repository that the Teacher can access. You wrote:
- I actually need a kind of FTP repository facility, but it does not exist.
- Maybe WebDav, but I still have not found a convincing step-by-step explanation of how to do this in the Moodle forums.
I tried to set up the WebDav using my cPanel with no success. It requires the administrator to setup the WebDav via cPanel, then each teacher must download and install the WebDav application. I couldn't get the server to accept the login credentials. I didn't contact my host, but I assume it won't work on a shared server.
So I took a closer look at the Moodle File System Repository. I found that you can combine the File System Repository with the Private Files Block so a teacher can access and upload files to both the Common Instance folders and the Private Instance folders using the File Picker. At least this is the way I think it is supposed to work. There is a bug that won't allow you to view the Private Instance folders in the File Picker (see http://tracker.moodle.org/browse/MDL-24210).
You can FTP files to the the File System Repository, but you have to have some way to give a teacher access to FTP. I tried the password protected function in cPanel but the teacher still has to download and install an FTP application like FileZilla. Then he must setup the username and password to access the password protected folders. This is complected and won't be easy for many teachers to setup.
I found an open source project at Net2FTP.com that I installed on my server. This works well because the administrator has the burden of setting up the folders and the login access. Then you can create a URL link to your Net2FTP server side application in each course and just give your teachers their login credentials. The teachers can only access the folders you have enabled for them but they can upload .zip files and extract them, create subfolders, rename and delete files, etc. If you have enabled the Moodle File System Repository, then they can ftp their files to their folder and then use them in Moodle using the Private Files block or the html editor File Picker .
Net2FTP does not appear to have added any features in the past year, but the product seems to be stable and it works well. It would be really great if someone could combine the features in Net2FTP with the File Picker. This would solove a lot of problems.
Hope this helps,