mapping to open existing file in a split window, creates a blank last line, then enters insert mode

Question

I am trying to combine several commands into a single mapping - (i) open a split window with a height of 15 lines, (ii) open an existing file in that window, (iii) move to the last line and char of that file, (iv) create a new blank line thereafter, (v) and enter insert mode.

This achieves (i) and (ii):

nnoremap <leader>n :15sp +$ $HOME/_notes/n0w<cr>

I've tried to extend upon it with:

nnoremap <leader>n :15sp +$A $HOME/path/to/file<cr>
nnoremap <leader>n :15sp +$ +A $HOME/path/to/file<cr>
nnoremap <leader>n :15sp +A +$  $HOME/path/to/file<cr>
nnoremap <leader>n :15sp +GA  $HOME/path/to/file<cr>

which has given the respective results:

E464: ambiguous use of user-defined command +$A
+A $/HOME/path/to/file [NEW DIRECTORY]
+S $/HOME/path/to/file [NEW DIRECTORY]
E492: not an editor command

I've also tried similar variations with +startinsert and +normal but not getting the desired result.

Would greatly appreciate help.

Answer 1

No need to embed commands in the split. You can use multiple commands in a single mapping.

nnoremap <leader>n :15sp $HOME/_notes/n0w<cr>Go

After the split command is submitted with <cr>, this being nmap we can just specify Normal mode commands. Specifically, G for step (iii) (go to end of file) and o for steps (iv) and (v) (add a new line and enter Insert mode).

That's it.

(An assist to @JürgenKrämer for a shorter command and subsequent revelation that I have config/plugin issues.)