Merge pull request #808 from alphapapa/wip/extensible-follow-links

Add extensible link-opening system

CHANGES.md

@@ -2,12 +2,19 @@
 
 *Under development*
 
+*   New Features:
+    - Variable `markdown-follow-link-functions` extends
+      `markdown-follow-link-at-point` similarly to Org's
+      `org-open-at-point-functions`, allowing other libraries to
+      handle links specially. [GH-780][]
+
 *   Bug fixes:
     - Don't highlight superscript/subscript in math inline/block [GH-802][]
 
 *   Improvements:
     - Apply url-unescape against URL in an inline link [GH-805][]
 
+  [gh-780]: https://github.com/jrblevin/markdown-mode/issues/780
   [gh-802]: https://github.com/jrblevin/markdown-mode/issues/802
   [gh-805]: https://github.com/jrblevin/markdown-mode/issues/805
 

markdown-mode.el

@@ -73,6 +73,13 @@
 (defvar markdown-gfm-language-history nil
   "History list of languages used in the current buffer in GFM code blocks.")
 
+(defvar markdown-follow-link-functions nil
+  "Functions used to follow a link.
+Each function is called with one argument, the link's URL. It
+should return non-nil if it followed the link, or nil if not.
+Functions are called in order until one of them returns non-nil;
+otherwise the default link-following function is used.")
+
 
 ;;; Customizable Variables ====================================================
 
@@ -7923,11 +7930,11 @@ If the link is a complete URL, open in browser with `browse-url'.
 Otherwise, open with `find-file' after stripping anchor and/or query string.
 Translate filenames using `markdown-filename-translate-function'."
   (interactive (list last-command-event))
-  (save-excursion
-    (if event (posn-set-point (event-start event)))
-    (if (markdown-link-p)
-        (markdown--browse-url (markdown-link-url))
-      (user-error "Point is not at a Markdown link or URL"))))
+  (if event (posn-set-point (event-start event)))
+  (if (markdown-link-p)
+      (or (run-hook-with-args-until-success 'markdown-follow-link-functions (markdown-link-url))
+          (markdown--browse-url (markdown-link-url)))
+    (user-error "Point is not at a Markdown link or URL")))
 
 (defun markdown-fontify-inline-links (last)
   "Add text properties to next inline link from point to LAST."
@@ -8337,7 +8344,7 @@ See `markdown-follow-link-at-point' and
 `markdown-follow-wiki-link-at-point'."
   (interactive "P")
   (cond ((markdown-link-p)
-         (markdown--browse-url (markdown-link-url)))
+         (markdown-follow-link-at-point))
         ((markdown-wiki-link-p)
          (markdown-follow-wiki-link-at-point arg))
         (t

tests/markdown-test.el

@@ -51,17 +51,15 @@
   "Run BODY in a temporary buffer containing STRING in MODE."
   (declare (indent 2))
   `(let ((win (selected-window)))
-     (unwind-protect
-         (with-temp-buffer
-           (set-window-buffer win (current-buffer) t)
-           (erase-buffer)
-           (insert ,string)
-           (funcall ,mode)
-           (setq-default indent-tabs-mode nil)
-           (goto-char (point-min))
-           (font-lock-ensure)
-           (prog1 ,@body (kill-buffer)))
-       (ignore))))
+     (with-temp-buffer
+       (set-window-buffer win (current-buffer) t)
+       (erase-buffer)
+       (insert ,string)
+       (funcall ,mode)
+       (setq-default indent-tabs-mode nil)
+       (goto-char (point-min))
+       (font-lock-ensure)
+       ,@body)))
 
 (defmacro markdown-test-file-mode (mode file &rest body)
   "Open FILE from `markdown-test-dir' in MODE and execute BODY."