From dc7b26268398cc72eb7fad17acc4adc07fd6f55e Mon Sep 17 00:00:00 2001
From: Case Duckworth
Date: Tue, 15 Nov 2022 19:51:16 -0600
Subject: Customize browse-url

---
 lisp/browse-url-transform.el | 45 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 lisp/browse-url-transform.el

(limited to 'lisp/browse-url-transform.el')

diff --git a/lisp/browse-url-transform.el b/lisp/browse-url-transform.el
new file mode 100644
index 0000000..c290a1f
--- /dev/null
+++ b/lisp/browse-url-transform.el
@@ -0,0 +1,45 @@
+;;; browse-url-transform --- transform URLs
+
+(defgroup browse-url-transform nil
+  "Transformations for urls passed to `browse-url'."
+  :group 'browse-url)
+
+(defcustom browse-url-transform-alist nil
+  "Transformation rules for URLs.
+The keys are regexps matching URLs, and the values are how to
+transform them.  The replacements will use match capture data."
+  :type '(alist :key-type (string :tag "URL regexp match")
+                :value-type (string :tag "URL regexp transformation")))
+
+(defun browse-url-transform-url (url)
+  "Transform URL before passing it to `browse-url'."
+  (cl-loop with url = (substring-no-properties
+                       (if (consp url) (car url) url))
+           for (regex . transformation) in browse-url-transform-alist
+           if (string-match regex url)
+           return (replace-match transformation nil nil url)
+           finally return url))
+
+(defun browse-url-transform-advice (url &rest args)
+  "Advice to `browse-url' for URL transformations.
+ARGS are passed on for further processing."
+  (apply #'list (and url (browse-url-transform-url url)) args))
+
+(define-minor-mode browse-url-transform-mode
+  "Minor mode to transform a URL before passing it to `browse-url'.
+This can be used to \"redirect\" URLs, for example from an
+information silo to a more privacy-respecting one (e.g.,
+\"twitter.com\" -> \"nitter.com\"), by adding advice to `browse-url'.
+
+When using this mode, ensure that the transformed URL is also in
+`browse-url-handlers', since that's what `browse-url' will see."
+  :lighter " Turl"
+  :keymap nil
+  :global t
+  (cond (browse-url-transform-mode
+         (advice-add 'browse-url :filter-args #'browse-url-transform-advice))
+        (:else
+         (advice-remove 'browse-url #'browse-url-transform-advice))))
+
+(provide 'browse-url-transform)
+;;; browse-url-transform.el ends here
-- 
cgit 1.4.1-21-gabe81