Hi everyone! I’ve recently hacked up an obviously incomplete yet working PDF reader for Nyxt in my config. There’s a twist, though: it uses pdftotext to get PDF text and display it as a single <pre> tag. This might be unacceptable for someone used to picturesque PDFs, but is mostly enough for me reading the mere text of it.
Here’s the full listing for this feature:
(in-package #:nyxt-user)
;; I'm definining a new scheme to redirect PDF requests to. What it does is:
;; - Get the original file.
;; - Save it to disk.
;; - Run pdftotext over it.
;; - Display pdftotext output in a nice <pre> tag.
(define-internal-scheme "unpdf"
(lambda (url buffer)
(let* ((url (quri:uri url))
(original-url (quri:uri-path url))
(original-content (dex:get original-url :force-binary t)))
(uiop:with-temporary-file (:pathname path :type "pdf" :keep t)
(log:debug "Temp file for ~a is ~a" url path)
(alexandria:write-byte-vector-into-file
(coerce original-content '(vector (unsigned-byte 8))) path :if-exists :supersede)
(let ((text (uiop:run-program `("pdftotext" ,(uiop:native-namestring path) "-")
:output '(:string :stripped t))))
(spinneret:with-html-string
(:head (:style (style buffer)))
(:pre (or text "")))))))
:local-p t)
(define-command-global unpdf-download-this ()
"A helper for unpdf: pages to download the original PDF to the regular destination.
Unpdf redirects all requests, even those that you need to read
elsewhere, thus I need this command."
(let* ((buffer (current-buffer))
(url (url buffer)))
(if (string= "unpdf" (quri:uri-scheme url))
(ffi-buffer-download buffer (quri:uri-path url))
;; I need to turn it into a mode someday...
(echo-warning "This command is for unpdf: pages only, it's useless elsewhere!"))))
(defun redirect-pdf (request-data)
(if (uiop:string-prefix-p "application/pdf" (mime-type request-data))
;; I should somehow prompt about downloading instead...
(progn
(echo "Redirecting to the unpdf URL...")
(make-buffer-focus :url (quri:uri (str:concat "unpdf:" (render-url (url request-data)))))
;; Return nil to prevent Nyxt from downloading this PDF.
nil)
request-data))
(define-configuration web-buffer
((request-resource-hook (hooks:add-hook %slot-value% 'redirect-pdf))))
Is anyone interested in having this as an extension to their Nyxt?
And note that, if reading PDFs converted to text is possible in Nyxt, then reading full-blown PDFs should also be possible given enough developer/extension-writer effort 
