If for any reason you need to work on a remotely hosted project without building your local instance and you need to keep applying changes to a file and keep testing the changes on the remote environment it's useful to be able to load the local file through your Development tools and apply it to the remote without actually uploading the changes to the remote host.
But the linking of local files doesn't work without adjusting your browser preferences or using an add-on, because browsers block loading local files from remote locations for security reasons.
Change Firefox preferences for loading local files
To allow Firefox to load local files from remote locations there are three preferences that need to be added to your browser configuration manually.
The preferences are:
You can add them to the
prefs.js files directly or use the about:config tool:
Acknowledge the warning before the tool is opened and be careful what you do while in there. These preferences don't exist by default so we need to add them ourselves. Right-click to get the menu pop-up, or use the Shift + F10 keyboard shortcut.
All three preferences are String types so choose that option when creating them. First you enter the preference name:
and then the value for that particular preference:
Repeat for the remaining two preferences to get your local files to appear on the remote location.
You can add more than one remote location to the list of sites, simply separate them with spaces. Make sure you include the URI schema and exclude trailing
To find out more about this read the article on mozillaZine: Links to local pages do not work.