+Next, we add some functions to add keywords to a bibtex entry using a helm interface, and a new action to add keywords to entries from helm-bibtex.
+#+BEGIN_SRC emacs-lisp :tangle org-ref.el
+;; adapted from bibtex-utils.el
+;; these are candidates for selecting keywords/tags
+(defun org-ref-bibtex-keywords ()
+ "Get keywords defined in current bibtex file.
+These are in the keywords field, and are comma or semicolon separated."
+ (save-excursion
+ (goto-char (point-min))
+ (let (keywords kstring)
+ (while (re-search-forward "^\\s-*keywords.*{\\([^}]+\\)}" nil t)
+ ;; TWS - remove newlines/multiple spaces:
+ (setq kstring (replace-regexp-in-string "[ \t\n]+" " " (match-string 1)))
+ (mapc
+ (lambda (v)
+ (add-to-list 'keywords v t))
+ (split-string kstring "\\(,\\|;\\)[ \n]*\\|{\\|}" t)))
+ keywords)))
+
+;;;###autoload
+(defun org-ref-set-bibtex-keywords (keywords &optional arg)
+ "Add KEYWORDS to a bibtex entry.
+If KEYWORDS is a list, it is converted to a comma-separated string. The KEYWORDS are added to the beginning of the field. Otherwise KEYWORDS should be a string of comma-separate keywords."
+ (interactive "sKeywords: \nP")
+ (bibtex-set-field
+ "keywords"
+ (if arg
+ ;; replace with arg
+ (if (listp keywords)
+ (mapconcat 'identity keywords ", ")
+ keywords)
+ ;; else concatentate
+ (concat
+ (if (listp keywords)
+ (mapconcat 'identity keywords ", ")
+ keywords)
+ (when (not (string= "" (bibtex-autokey-get-field "keywords")))
+ (concat ", " (bibtex-autokey-get-field "keywords"))))))
+ (save-buffer))
+
+;;;###autoload
+(defun helm-tag-bibtex-entry ()
+ "Helm interface to add keywords to a bibtex entry.
+Run this with the point in a bibtex entry."
+ (interactive)
+ (let ((keyword-source `((name . "Existing keywords")
+ (candidates . ,(org-ref-bibtex-keywords))
+ (action . (lambda (candidate)
+ (org-ref-set-bibtex-keywords
+ (mapconcat
+ 'identity
+ (helm-marked-candidates)
+ ", "))))))
+ (fallback-source `((name . "Add new keywords")
+ (dummy)
+ (action . (lambda (candidate)
+ (org-ref-set-bibtex-keywords helm-pattern)
+ )))))
+ (helm :sources '(keyword-source fallback-source))))
+
+(defun helm-bibtex-show-entry (key)
+ "Show the entry in the BibTeX file.
+The original function in helm-bibtex has a bug where it finds the
+first key that partially matches. This version avoids that."
+ (catch 'break
+ (dolist (bibtex-file (if (listp helm-bibtex-bibliography)
+ helm-bibtex-bibliography
+ (list helm-bibtex-bibliography)))
+ (let ((buf (helm-bibtex-buffer-visiting bibtex-file))
+ (entries '()))
+ (find-file bibtex-file)
+ (bibtex-map-entries
+ (lambda (key start end)
+ (add-to-list 'entries (cons key start))))
+ (if (assoc key entries)
+ (progn
+ (goto-char (cdr (assoc key entries)))
+ (throw 'break t))
+ (unless buf
+ (kill-buffer)))))))
+