master e560f9af8e8 06/11: Allow ERC modules to extend erc-nick-popup-alist

[F. Jason Park]

branch: master
commit e560f9af8e8edb2cd41a08c6b0e8637cbac7b1f5
Author: F. Jason Park <jp@neverwas.me>
Commit: F. Jason Park <jp@neverwas.me>

    Allow ERC modules to extend erc-nick-popup-alist
    
    * etc/ERC-NEWS: Mention changes to `erc-button-alist' and superficial
    changes to `erc-nick-popup-alist'.
    * lisp/erc/erc-button.el (erc-nick-popup-alist): Change type to prefer
    associating strings with functions instead of arbitrary sexps.
    (erc-button-cmd-KICK, erc-button-cmd-MSG): New functions to serve as
    interrogative wrappers for `erc-cmd-KICK' and `erc-cmd-MSG' in
    `erc-nick-popup-alist'.  The first also fixes a bug in which all but
    the first token of a given "reason" would be omitted from the
    ":trailing" portion of an outgoing "KICK" message.
    (erc-button--nick-popup-alist): New variable to help built-in modules
    expose special actions to `erc-nick-popup' without touching
    `erc-nick-popup-alist'.
    (erc-nick-popup): Present members from both `erc--nick-popup-alist'
    and `erc-nick-popup-alist' to the invoking user.  Accommodate
    functions as well as arbitrary sexps.  (bug#63569)
---
 etc/ERC-NEWS           | 18 +++++++++-----
 lisp/erc/erc-button.el | 64 ++++++++++++++++++++++++++++++++++++--------------
 2 files changed, 59 insertions(+), 23 deletions(-)

diff --git a/etc/ERC-NEWS b/etc/ERC-NEWS
index 5753120107a..1534f0adc25 100644
--- a/etc/ERC-NEWS
+++ b/etc/ERC-NEWS
@@ -116,13 +116,19 @@ asking users who've customized this option to switch to
 that some other solution, like automatic migration, is justified,
 please make that known on the bug list.
 
-** The 'nicknames' entry in 'erc-button-alist' is officially exceptional.
+** 'erc-button-alist' and 'erc-nick-popup-alist' have evolved slightly.
 It's no secret that the 'buttons' module treats potential nicknames
-specially.  To simplify ERC's move to next-gen "rich UI" extensions,
-this special treatment is being canonized.  From now on, all values
-other than the symbol 'erc-button-buttonize-nicks' appearing in the
-"FORM" field (third element) of this entry are considered deprecated
-and will incur a warning.
+specially.  This is perhaps most evident in its treatment of the
+'nicknames' entry in 'erc-button-alist'.  Indeed, to simplify ERC's
+move to next-gen "rich UI" extensions, this special treatment is being
+canonized.  From here on out, this entry will no longer appear in the
+option's default value but will instead be applied implicitly so long
+as the option 'erc-button-buttonize-nicks' is non-nil, which it is by
+default.  Relatedly, the option 'erc-nick-popup-alist' now favors
+functions, which ERC calls non-interactively, over arbitrary
+s-expressions, which ERC will continue to honor.  Although the default
+lineup remains functionally equivalent, its members have all been
+updated accordingly.
 
 ** Option 'erc-query-on-unjoined-chan-privmsg' restored and renamed.
 This option was accidentally removed from the default client in ERC
diff --git a/lisp/erc/erc-button.el b/lisp/erc/erc-button.el
index 3045bb44889..931236891bf 100644
--- a/lisp/erc/erc-button.el
+++ b/lisp/erc/erc-button.el
@@ -685,20 +685,20 @@ greater than `point-min' with a text property of 
`erc-callback'.")
 ;;; Nickname buttons:
 
 (defcustom erc-nick-popup-alist
-  '(("DeOp"  . (erc-cmd-DEOP nick))
-    ("Kick"  . (erc-cmd-KICK (concat nick " "
-                                     (read-from-minibuffer
-                                      (concat "Kick " nick ", reason: ")))))
-    ("Msg"   . (erc-cmd-MSG (concat nick " "
-                                    (read-from-minibuffer
-                                     (concat "Message to " nick ": ")))))
-    ("Op"    . (erc-cmd-OP nick))
-    ("Query" . (erc-cmd-QUERY nick))
-    ("Whois" . (erc-cmd-WHOIS nick))
-    ("Lastlog" . (erc-cmd-LASTLOG nick)))
+  '(("DeOp"  . erc-cmd-DEOP)
+    ("Kick"  . erc-button-cmd-KICK)
+    ("Msg"   . erc-button-cmd-MSG)
+    ("Op"    . erc-cmd-OP)
+    ("Query" . erc-cmd-QUERY)
+    ("Whois" . erc-cmd-WHOIS)
+    ("Lastlog" . erc-cmd-LASTLOG))
   "An alist of possible actions to take on a nickname.
-An entry looks like (\"Action\" . SEXP) where SEXP is evaluated with
-the variable `nick' bound to the nick in question.
+For all entries (ACTION . FUNC), ERC offers ACTION as a possible
+completion item and calls the selected entry's FUNC with the
+buttonized nickname at point as the only argument.  For
+historical reasons, FUNC can also be an arbitrary sexp, in which
+case, ERC binds the nick in question to the variable `nick' and
+evaluates the expression.
 
 Examples:
  (\"DebianDB\" .
@@ -706,18 +706,48 @@ Examples:
    (format
     \"ldapsearch -x -P 2 -h db.debian.org -b dc=debian,dc=org ircnick=%s\"
     nick)))"
+  :package-version '(ERC . "5.6") ; FIXME sync on release
   :type '(repeat (cons (string :tag "Op")
-                       sexp)))
+                       (choice function sexp))))
+
+(defun erc-button-cmd-KICK (nick)
+  "Prompt for a reason, then kick NICK via `erc-cmd-KICK'.
+In server buffers, also prompt for a channel."
+  (erc-cmd-KICK
+   (or (and erc--target (erc-default-target))
+       (let ((targets (mapcar (lambda (b)
+                                (cons (erc--target-string
+                                       (buffer-local-value 'erc--target b))
+                                      b))
+                              (erc-channel-list erc-server-process))))
+         (completing-read (format "Channel (%s): " (caar targets))
+                          targets (pcase-lambda (`(,_ . ,buf))
+                                    (with-current-buffer buf
+                                      (erc-get-channel-user nick)))
+                          t nil t (caar targets))))
+   nick
+   (read-from-minibuffer "Reason: ")))
+
+(defun erc-button-cmd-MSG (nick)
+  "Prompt for a message to NICK, and send it via `erc-cmd-MSG'."
+  (let ((msg (read-from-minibuffer (concat "Message to " nick ": "))))
+    (erc-cmd-MSG (concat nick " " msg))))
+
+(defvar-local erc-button--nick-popup-alist nil
+  "Internally controlled items for `erc-nick-popup-alist'.")
 
 (defun erc-nick-popup (nick)
   (let* ((completion-ignore-case t)
+         (alist (append erc-nick-popup-alist erc-button--nick-popup-alist))
          (action (completing-read (format-message
                                    "What action to take on `%s'? " nick)
-                                  erc-nick-popup-alist))
-         (code (cdr (assoc action erc-nick-popup-alist))))
+                                  alist))
+         (code (cdr (assoc action alist))))
     (when code
       (erc-set-active-buffer (current-buffer))
-      (eval code `((nick . ,nick))))))
+      (if (functionp code)
+          (funcall code nick)
+        (eval code `((nick . ,nick)))))))
 
 ;;; Callback functions
 (defun erc-button-describe-symbol (symbol-name)