Usage from nvim-cmp missing and naive approach with using `name = 'ctags'` does not work.

[matu3ba]

I would have expected that

local cmp = require 'cmp'
cmp.setup {
  mapping = cmp.mapping.preset.insert {
    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-e>'] = cmp.mapping.abort(),
    ['<CR>'] = cmp.mapping.confirm { select = true }, -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
  },
  sources = cmp.config.sources({
    { name = 'buffer' },
    { name = 'ctags' },
    { name = 'nvim_lsp' },
    -- { name = 'vsnip' }, -- For vsnip users.
    -- { name = 'luasnip' }, -- For luasnip users.
    -- { name = 'ultisnips' }, -- For ultisnips users.
    -- { name = 'snippy' }, -- For snippy users.
  }),
}

would do the job for me, but completions are not showing up.
For example, I checked that C-] jumps to the correct enum, but the field values are not completed.

For additional context, I use the following script to generate the tags (with universal ctags)

#!/bin/sh
set -e
PATH="/usr/local/bin:$PATH"
PID=$$
#if [ -z ${var+x} ]; then echo "'$1' is unset, need paths to create ctags for"; exit; fi

if test "$#" -lt 1; then
  echo "Usage: $0 FILE1 [.. FILEN], need paths to create ctags for" >&2
  exit 1
fi

trap 'rm -f "${PID}tags"' EXIT
ctags --recurse=yes --kinds-c++=+p -f "${PID}tags" --extras=+fq --sort=foldcase \
  --c++-kinds=+p --fields=+iaS --extras=+q "$@"
mv "${PID}tags" "tags"

[matu3ba]

By the way, using { name = 'cmp-ctags' }, or { name = 'cmp_ctags' } neither works.
For some reasons nvim-cmp also does not show me buffer completions for the other open buffers, only text ones.
But I guess thats just additional necessary configuration, which is not a default.

Is there something I am missing?

[matu3ba]

UPDATE

Apparently the following works with <C-n> and <C-p>, but it does not integrate with <C-Space>.

1. Is there an option to make a custom mapping to complete ctags?
2. Any idea why is there no vim/neovim inbuild to complete from tags files in :h i_CTRL-X_CTRL-D?

cmp.setup {
  mapping = cmp.mapping.preset.insert {
    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-e>'] = cmp.mapping.abort(),
  },
  sources = cmp.config.sources({
    { name = 'cmp_ctags' },
    { name = 'nvim_lsp' },
  }),
}

UPDATE2

    ['<C-t>'] = cmp.mapping.complete({
        config = {
          sources = {
            { name = 'cmp_ctags' },
          }
        }
      })

could work. I need to test this.
However looking at the code shows 1 instance is spawned for each source file, which does not scale.
At least how I understand it, this plugin does not match the results against the tags file, because I could not find that keyword anywhere.

[saeedan2000]

I appreciate your updates, as I'm trying to figure out the same thing.

[saeedan2000]

Seems like you figured it out, but just in case mine is working after looking at the setup from the LunarVim repo.
I think you also need
vim_item.menu = ({ ctags = "[Ctags]", })[entry.source.name]
inside formatting.

[GordianDziwis]

This should work:

formatting = {
       format = function(entry, vim_item)
           vim_item.menu = ({
               ctags = 'T',
           })[entry.source.name]
           return vim_item
       end,
   },
   sources = {
       { name = 'ctags' },
   },