Re: Is it alright to define-derived-mode dynamically?

[Jean Louis]

Thank you Stefan, I followed your advise and disintegrated
functions. But it as tedious until I got it working.

(defun rcd-db-report (title entries tabulated-list-format table 
tabulated-list-sort-key)
  (let* ((title (generate-new-buffer-name (concat "RCD Database: " title))))
    (let* ((buffer title)
           (buffer (get-buffer-create buffer))
           (mode-map (rcd-db-table-mode-map table)))
      ;; (message "Keymap: %s" table)
      (switch-to-buffer-other-window buffer)
      (delete-other-windows)
      (rcd-db-list-mode) ;; TODO if I move it from this line, weird things 
happen
      (use-local-map mode-map) ;; TODO if I move it from this line, weird 
things happen
      (tabulated-list-init-header)
      (setq tabulated-list-padding 1))
      (setq tabulated-list-format tabulated-list-format)
      (setq tabulated-list-entries entries)
      (setq tabulated-list-sort-key tabulated-list-sort-key)
      ;;(tabulated-list-init-header)
      (tabulated-list-print t)))

I have noticed that I could not just place `use-local-map' anywhere I
wanted and by apparent random attempts I got it working. I do not know
where the problem was.

Problem was invoking another derived mode from tabulated-list-mode
where the other mode did appear and it was populated but it was not
visible. The text I could not see but entries were there and the lines
in existence, just everything white.

> First:
> - It should be called `rcd-db-list-mode`.

Done.

> - Don't use global variables's names for local variables.

Did you mean:

(defvar-local rcd-tabulated-marked-items nil
  "Collects IDs for tabulated list modes")

Now I use `defvar-local', so no need to to make it local additionally.

I use that variable to mark items in the list so that I may make mass
actions on various items.

I was first thinking that function `tabulated-list-put-tag' does that.
But it just places the tag. I cannot track the tag or process items by
using the tag. It seem to be just visual tool.

> - I doubt the mode needs `hl-line-mode`.  If *you* like it, then use
> something like (add-hook 'tabulated-list-mode-mode #'hl-line-mode)
> in your init file.

Done. I am using it that way now.

Cursor is harder visible, I have made some quick delete functions
without confirmation, so highlightin lines helps not to make mistake.

> And you can do:
> 
>     (define-derived-mode rcd-db-list-mode tabulated-list-mode "Database List"
>       "Major mode to manipulate Database List reports."
>       [...])
> 
>     (defun rcd-db-report ( title entries &optional list-format
>                            list-sort-key mode-map)
>       [...]
>       (rcd-db-list-mode)
>       (use-local-map mode-map))

Done.

I am doing that now, and you have noticed I guess so, that all that
was to invoke different keymaps for different SQL tables.

Thank you,
Jean