Add PDF.js viewer for PDF files

[mbrgm]

Would PDF.js be a conceivable addition to the Web UI? This could allow viewing PDFs just like it is already possible for images.

[mpl]

Maybe? :-)

Since chrome (I don't know about other browsers) already allows viewing PDFs, I don't know how much of a gain that would be. If you select a pdf permanode, then click on "view original", then you can read the PDF without any need of a 3rd party lib.
It would be nice to have a preview of the PDF displayed instead of the blank permanode "icon" but I suspect we could (and hence would like to) do most of the work for that server-side. But I haven't thought about that much, so again, maybe.

Thanks for the link though.

[mbrgm]

I think it also depends on what's the general philosophy regarding (pre-)viewing several filetypes in the Web UI. Obviously, previewing images and videos just works™ when clicking on the icon, but for .pdf or .txt files, users have to 'view original' in order to read the document. Clicking the icon only gives 'no result found', while there's a special view for images and videos.

Maybe you could elaborate on whether there are plans for handling various filetypes @mpl?

[mpl]

@mbrgm There are no definite/precise plans that I know of. Easy handling of common files (such as text or pdf) is definitely on the table, and how to do it is open for discussion.
It just happens that:

1. We usually favor server-side work if we can
2. We're kindof in the middle of (re)defining how we're going to work on the UI moving forward
3. In the long run, even the web UI could be a stand-alone app, which should make it easier for anyone to swap it with their own, preferred, app/UI.

[bradfitz]

I'd like to see PDF support, especially if it helps with thumbnails of PDFs or easier browsing of PDFs with our UI overlayed (in any browser, not just Chrome).

[ginabythebay]

Perhaps consider poppler? https://poppler.freedesktop.org/. Works on windows and unix-like systems.

It includes the command line tool pdftocairo which can convert pdfs to jpegs, so could be used to create thumbnails. I use the poppler code every day to view pdfs in emacs on windows (via pdf-utils) and have yet to find a pdf it won't display but that adobe or chrome will.

[mpl]

I think https://perkeep-review.googlesource.com/c/perkeep/+/19206 will address this issue.