By default Jiglu allows users to contribute any kind of attachment to discussion messages, knowledge entries or blog posts or as instant message files. However, there may be cases where you want to limit what can be distributed, for example to only allow simple image formats or Microsoft Office file formats.
To do this go to the System settings and then choose the Filtering option. This contains two lists:
- Media types that you always want to filter out, including wildcards
- Media types that you always want to allow, including wildcards, even if they are in the above list.
For example, if you only want to allow GIF, JPEG and PNG images:
- In the first list scroll down to the bottom of the list and select all the checkboxes under the Wildcards section.
- In the second list scroll down to the Images section and select the checkboxes next to the GIF image, JPEG image and PNG image media types.
After selecting Save the system will now limit attachments and files to just those media types. If anyone tries and adds a file with a disallowed media type using the web interface then it will be rejected and the user will be informed. If they try and email a discussion message to the system with an attachment that has a disallowed media type then it will be stripped from the message.
The system determines the media type of a file in several ways. It can be supplied by a browser or in an email, but if this is not available it may make an initial guess based on the file extension. When the content of a file is parsed to extract metadata the media type may be reassigned if content analysis shows it differs from that previously supplied.