bug#29533: Fwd: [Feature Request] ERC: let erc-join-channel support to select channels from history or a defined list

[Noam Postavsky <npostavs@gmail.com>]

stardiviner <numbchild@gmail.com> writes:

> ;;; original code
> (defun erc-join-channel (channel &optional key)
>   "Join CHANNEL.
>
> If `point' is at the beginning of a channel name, use that as default."
>   (interactive
>    (list [...]

> (defun erc-join-channel-select (args)
>   "Select a channel to join from alist of channels to."
>   (let ((channel (completing-read
>                   "Select a channel: "
>                   (cdr (assoc
>                         (completing-read "Select a server: "
>                                          (mapcar 'car erc-join-channels-alist))
>                         erc-join-channels-alist)))))
>     (setq args (list channel))))

> (advice-add 'erc-join-channel :filter-args 'erc-join-channel-select)

> When I press [C-c C-j] (erc-join-channel), the advice is added on function,
> but seems not working. Don't know why, do you have any clue?

I think advice doesn't affect interactive calls the way you expect.  I
forget the details of it, but anyway it's probably better to just remap
instead, along the lines of:

    (defun erc-join-channel-select ()
      "Select a channel to join from alist of channels to."
      (erj-join-channel
       (completing-read
        "Select a channel: "
        (cdr (assoc
              (completing-read "Select a server: "
                               (mapcar 'car erc-join-channels-alist))
              erc-join-channels-alist)))))

    (define-key erc-mode-map [remap erc-join-channel] 'erc-join-channel-select)