+
+* ISBN utility
+These are not really doi utilities, but for now I am putting them here.
+
+I found this on the web. It can be handy, but the bibtex entry has a lot of stuff in it.
+
+#+BEGIN_SRC emacs-lisp :tangle doi-utils.el
+(defun isbn-to-bibtex-lead (isbn)
+ "Search lead.to for ISBN bibtex entry. You have to copy the entry if it is on the page to your bibtex file."
+ (interactive "sISBN: ")
+(browse-url
+(format "http://lead.to/amazon/en/?key=%s+&si=all&op=bt&bn=&so=sa&ht=us" isbn)))
+#+END_SRC
+
+Here we get isbn metadata and build a bibtex entry.
+http://xisbn.worldcat.org/xisbnadmin/doc/api.htm#getmetadata
+
+
+#+BEGIN_SRC emacs-lisp :tangle doi-utils.el
+(defun isbn-to-bibtex (isbn bibfile)
+ "Get bibtex entry for ISBN and insert it into BIBFILE unless an
+entry with the generated key already exists in the file."
+ (interactive
+ (list
+ (read-input
+ "ISBN: "
+ ;; now set initial input
+ (cond
+ ;; If region is active and it starts with a number, we use it
+ ((and (region-active-p)
+ (s-match "^[0-9]" (buffer-substring (region-beginning) (region-end))))
+ (buffer-substring (region-beginning) (region-end)))
+ ;; if first entry in kill ring starts with a number assume it is an isbn
+ ;; and use it as the guess
+ ((if (s-match "^[0-9]" (car kill-ring))
+ (car kill-ring)))
+ ;; type or paste it in
+ (t
+ nil)))
+ (ido-completing-read
+ "Bibfile: "
+ (append (f-entries "." (lambda (f) (f-ext? f "bib")))
+ org-ref-default-bibliography))))
+
+ (let* ((results (with-current-buffer
+ (url-retrieve-synchronously
+ (format
+ "http://xisbn.worldcat.org/webservices/xid/isbn/%s?method=getMetadata&format=json&fl=*"
+ isbn))
+ (json-read-from-string
+ (buffer-substring url-http-end-of-headers (point-max)))))
+ (status (cdr (nth 1 results)))
+ (metadata (aref (cdar results) 0))
+ (new-entry)
+ (new-key))
+
+ ;; check if we got something
+ (unless (string= "ok" status)
+ (error "Status is %s" status))
+
+ ;; construct an alphabetically sorted bibtex entry. I assume ISBN numbers go
+ ;; with book entries.
+ (setq new-entry
+ (concat "\n@book{,\n"
+ (mapconcat
+ 'identity
+ (loop for field in (-sort 'string-lessp (mapcar 'car metadata))
+ collect
+ (format " %s={%s}," field (cdr (assoc field metadata))))
+ "\n")
+ "\n}\n"))
+
+ ;; build entry in temp buffer to get the key so we can check for duplicates
+ (setq new-entry (with-temp-buffer
+ (insert new-entry)
+ (org-ref-clean-bibtex-entry)
+ (setq new-key (bibtex-key-in-head))
+ (buffer-string)))
+ (find-file bibfile)
+ (goto-char (point-min))
+ (when (search-forward new-key nil t)
+ (beep)
+ (setq new-key (read-input
+ (format "%s already exists. Enter new key (C-g to cancel): " new-key)
+ new-key)))
+ (goto-char (point-max))
+ (insert new-entry)
+ ;; set key. It is simplest to just replace it, even if it is the same.
+ (bibtex-beginning-of-entry)
+ (re-search-forward bibtex-entry-maybe-empty-head)
+ (if (match-beginning bibtex-key-in-head)
+ (delete-region (match-beginning bibtex-key-in-head)
+ (match-end bibtex-key-in-head)))
+ (insert new-key)
+ (bibtex-fill-entry)
+ (save-buffer)))
+#+END_SRC
+
+
+