By default, CMS editors will only be able to upload a file with an extension in the
CMS editors can see the current extensions allowed by going into the CMS "Files" section, hitting the "Upload" button and clicking "Show allowed extensions".
To allow someone to upload a file extension that does not appear in this list, you will need to add some code to
support this. In this example, we'll allow files with the
.sspak extension to be uploaded.
mysite/_config/config.yml file, add the following to register the new extension:
File: allowed_extensions: - 'sspak'
Additionally, you will need to add the MIME type of
.sspak files into the
HTTP.MimeTypes config setting, as uploads
will have extra checks to ensure the file content matches the uploaded extension, and that's done using the MIME type.
To find the MIME type of the file, first locate an example of an
.sspak file, and run the following command line
utility to get the MIME type:
file -i /path/to/my/file.sspak
Note: OS X requires the argument
-i in the above example to be
The output will be something like this:
file.sspak: application/x-tar; charset=binary
You'll want the
application/x-tar part in the output. Given that, once again open
and add the following to register the new MIME type:
HTTP: MimeTypes: 'sspak': 'application/x-tar'
This will globally allow the new extension to be uploaded, this covers all instances of
UploadField used in the CMS,
as well as the frontend of your website.
For reference, a MIME type list can be found on the IANA website.