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Bringing back previewing PDFs inline without downloading the file*
I've recently made the switch to Firefox last month and was trying to view a PDF embedded inline on a site (Canvas, commonly used in schools and universities), but kept getting a blank box. I had to download the file to view it- I couldn't just preview it. I'm aware that "previewing" or "opening" PDFs without choosing to save them actually just saved them to a temp folder locally which the system would delete eventually on its own, and this new change from version 98+ supposedly "optimizes" the download process because "Firefox no longer saves files to a temporary folder because of the downsides to saving files in a location that is hard to discover."
Downsides? What downsides???
Removing that feature quite literally does the opposite of optimizing when the average user, and in fact all users, benefit from being able to preview PDFs by keeping them in a temp folder. If we wanted to download something, we would choose to save the file where we want it to be. You're literally presenting "save file" and "open file" as if they're two different choices, when "open file" is really just "save file, and then we open it for you, and you have to manually delete it yourself later!". This is objectively a downgrade in every way. There's no optimization here. I realize that me as just one person asking for this will fall on deaf ears, but I have to try. Please bring back the option to preview files by automatically saving them to a temp folder without me having to set my default download folder for ALL files as a temp folder.
Please think about the situation of someone like a teacher who needs to mark 40 students' PDF homework submissions in Canvas, which lets you quickly change between inline previews within the site of each PDF with its grading UI on the side, making it convenient for them to grade. With this change they either have to download 40 PDFs onto their hard drive, or go back to using Chrome, where the PDF.js extension (the very same PDF viewer that's built into Firefox and backed by Mozilla?!) actually will let them preview the temp files, no problem. And I'm not even teaching right now, I'm just a student who fell into this rabbit hole because I wanted to do my homework and all the PDFs are blank boxes in Firefox while they appear just fine on Chrome.
I really want to be using Firefox full time. I really do! But by taking away this very useful feature, you're literally forcing my hand into using Chrome again.
Wšykne wótegrona (1)
I've done some further reading and found a temporary jank workaround supplied to me by a friend who knows this stuff better than me. Putting this as a reply for anyone who stumbles across this thread because of the same problem in the future. I don't know if this will be foolproof or patched out in future versions, sadly.
- in a new tab, go to about:config
- change browser.download.start_downloads_in_tmp_dir to TRUE
- search for and delete these 2 preferences, don't worry if they reappear:
- pdfjs.enabledCache.state
- pdfjs.migrationVersion
The friend says it's stored in the cache. I tested it and can confirm I no longer get the PDFs in my download folder- they appear in FF's download tray and checking the location, they are back in a temp folder now. Works for me! Doesn't fix the inline PDF embed in Canvas, but livable enough for now. Will still use Chrome if I have to grade students' homework.
On a related note, in my research I was reading this thread: https://bugzilla.mozilla.org/show_bug.cgi?id=1738574#c127 about this issue between thedev :Gijs and users who have a problem with this removal. I have to say that I'm by no means a power user, just slightly more informed than the average joe. A very polite, well written, and thorough critique by lrdix (and many other users later down the thread!) from a power user's perspective mirrors my thoughts too as an average joe consumer, but it seemed to deeply offend the dev and was called rude... If that's rude, I worry about the dev if he ever reads my post. Sorry if I came off as rude, guy- I was an angry and frustrated user. For any readers in the future, that thread is long but explains the exact technical reasons they decided to remove this feature.
Please understand, devs, I'm not sure where you got the idea this change was better for average joe users, but all this does is vastly clog up downloads folders and hard drive space without the average joes even knowing it's taking up space, even if they're using the "open in FF" feature more.