Is there a browser preference that will permit extensions to fetch from local disk?

Add-ons Development
#1

Is there a browser preferences setting that the user can alter to permit an extension to fetch resources from the local disk?

I found that there is one to alter to permit a local HTML file to fetch resource files from the local disk, which is security.fileuri.strict_origin_policy. That is needed even if the local HTML file and resource files are from he same origin.

Thank you.

How to access local files from an extension?
#2

I don’t think so.

Perhaps the one you needed to modify was this newer preference introduced in Firefox 68:

Relaxing that older restriction allows traversing parent folders:

#3

Thank you. I like that local files have separate origins because it appears to permit separate indexedDB databases for each origin.

Maybe I am misunderstanding something but it seems that the security.fileuri.strict_origin_policy is doing more than relaxing same-origin. My requests are same origin but won’t work unless this preference is changed. I understand why from a different article you gave me a link to before concerning some type of phone app breach which was done within the same origin also.

It appears that communication between same-origin iframes with the parent and same-origin fetch are forbidden unless this preference is changed. Is there not one that would maintain same origin but permit communication again within same origin?

Thank you.

#4

I think there are only those two preferences to work with.

#5

Thank you. Now that I’ve come to see just how bad an idea it was of my mine to attempt to use databases in local HTML pages, I will give that new preference you provided a try. It may be just what I needed. I appreciate your help.

Sometimes I should, perhaps, stop and think that if what I think I’d like to have isn’t available, there might be a good reason for it ; and I better rethink my approach. I tend to learn my lessons the hard way.

I’m pretty sure that I tried this before, when you suggested it in a different question of mine concerning iframes and the parent page in same-origin local HTML files no longer being able to communicate, and it didn’t permit it; but the old preference did. I will have to try again and see if it works in this situation.

Thanks again.