ibuffer subgrouping

Question

I'm trying to group my buffers by tramp connections (like ibuffer-tramp does) but inside the tramp filters it keep my custom filter groups that I defined via

(setq ibuffer-saved-filter-groups
 '(("Default"
    ("Unsaved" (modified))                      ; All unsaved buffers
    ("Stars"   (starred-name))                  ; Group *starred*
    ("Start"   (name          . "\\*scratch\\*")) ; By regexp
    ("Dired"   (mode          . dired-mode))    ; Filter by mode
    ("Org"     (filename      . ".org"))        ; By filename
    ("Scheme"  (directory     . "~/scheme*"))   ; By directory
    ("Gnus" (or                                 ; Or multiple!
           (saved        . "gnus")
           (derived-mode . bbdb-mode))))))

My current issue is that ibuffer-tramp overwrites by ibuffer-saved-filter-groups. Sadly i'm super new to lisp and I'm not finding a way to put the two together. In the ibuffer-tramp documentation it says :

;; Alternatively, use `ibuffer-tramp-generate-filter-groups-by-tramp-connection'
;; to programmatically obtain a list of filter groups that you can
;; combine with your own custom groups.

I was hoping this can help me manage to create subgroups or similar but I couldn't find a solution.

At the very least it could be nice if all tramp similar connections (same hostname) are grouped together in separate filters. Like I would get the [ host1 ] at the top of ibuffer list then [ host 2 ] and then [ Unsaved ] etc...

How can I do that?

Answer 1

I ended up using perspective with iBuffer. By default using persp-iBuffer only show current perspective buffers. But when iBuffer is updated, all buffers are displayed (from ALL persp) thus I added this advice:

;; Function to add advice to `ibuffer-update` for filtering buffers
(defun persp-ibuffer-advise-update (&rest _args)
  "Advise `ibuffer-update` to filter buffers before updating using the `persp-ibuffer` logic."
  (when (and persp-mode (not (eq this-command 'ibuffer)))
    (setq ibuffer-maybe-show-predicates (append ibuffer-maybe-show-predicates
                                               (list #'(lambda (buf) (persp-buffer-filter buf t)))
                                               ido-ignore-buffers))))

;; Add the advice to `ibuffer-update` to apply the filtering logic
(advice-add 'ibuffer-update :before #'persp-ibuffer-advise-update)

Now instead of opening a new tramp connection directly via C-x d is use a custom function that creates a new persp and opens the tramp connection:

;;; Custom function to connect to an SSH and create a persp at the same time
(defun my-validate-ssh-target (ssh-target)
  "Validate the SSH target format (user@host)."
  (if (string-match-p "^[^@]+@[^@]+$" ssh-target)
      ssh-target
    (error "Invalid SSH target format. Please use 'user@host'.")))

(defun my-persp-ssh ()
  "Prompt for an SSH target and create a new perspective with a dired buffer for that connection."
  (interactive)
  ;; Prompt for SSH target
  (let* ((ssh-target (my-validate-ssh-target (read-string "SSH Target (user@host): ")))
         (persp-name (read-string "New perspective name: ")))
    ;; Ensure persp-mode is enabled
    (unless persp-mode
      (persp-mode 1))
    ;; Create new perspective
    (persp-switch persp-name)
    ;; Open TRAMP dired buffer in new perspective
    (dired (concat "/ssh:" ssh-target ":"))))

This is a working solution to my problem, but I agree that it doesn't directly use subgrouping. (I'm not sure I can thus close the question)