excluding plugin loading based on file type in Neovim's Lazy Loading configuration

[iton0]

is there a way instead of ft being a table of filetypes to load on it is a table of filetypes to NOT load on.
ex) ft = 'java' -- meaning would not load plugin on java filetype

[dpetka2001]

Why don't you use the cond? Something like

  {
    "folke/flash.nvim",
    cond = function()
      return not string.match(vim.fn.fnamemodify(vim.fn.bufname("%"), ":t"), ".*%.js")
    end,
  },

would not load flash.nvim in a JS file. That would obviously only work if you did nvim some.js. If you did nvim some.css and then opened a .js file from inside Neovim, it wouldn't work because the plugin would have already been loaded from opening the .css file and I don't believe there's a way to unload a plugin once it's been required and loaded (I might be wrong on that, so someone pls correct me if I'm wrong).

[iton0]

I implemented the code you provided. This is what I have:

return function()
    local current_buf = vim.api.nvim_get_current_buf()
    local filename = vim.fn.fnamemodify(vim.fn.bufname(current_buf), ':t')

    -- Excluded filetypes
    local filetypes = { -- Add more file extensions here
      'gitcommit',
      'gitconfig',
      'json',
    }

    local patterns = {}
    for _, ext in ipairs(filetypes) do
      table.insert(patterns, string.format('.*%s$', ext))
    end

    local is_not_desired_filetype = true
    for _, pattern in ipairs(patterns) do
      if string.match(filename, pattern) then
        is_not_desired_filetype = false
        break
      end
    end

    return is_not_desired_filetype
  end

However, if I start my neovim session in an excluded filetype it disables (puts the plugin under 'Disabled' instead of 'Not Loaded') the plugin for the duration of the session. My question is now how to enable a disabled plugin.

[dpetka2001]

Yes, that's what the cond does. I don't think you can enable a disabled plugin if it has been marked as disabled due to the cond. You have to restart Neovim, because lazy.nvim keeps an internal state of which plugins should be disabled.

[iton0]

I was able to make an autocommand:

vim.api.nvim_create_autocmd({ 'BufReadPost', 'BufNewFile' }, {
  pattern = '*',
  callback = function()
    vim.defer_fn(function()
      local excluded_fts = function()
        local current_buf = vim.api.nvim_get_current_buf()
        local filename = vim.fn.fnamemodify(vim.fn.bufname(current_buf), ':t')
        local current_filetype =
          vim.api.nvim_buf_get_option(current_buf, 'filetype')

        -- Excluded filetype
        -- Can either add the filetype or file extensions
        -- ex. 'text' or 'txt'
        local filetypes = {
          'php',
          'gitcommit',
          'lazy',
          'TelescopePrompt',
          'gitconfig',
        }

        for _, filetype in ipairs(filetypes) do -- Checks filetype
          if current_filetype == filetype then
            return true -- Skip for excluded filetypes
          end
        end

        local patterns = {}
        for _, ext in ipairs(filetypes) do
          table.insert(patterns, string.format('.*%s$', ext))
        end

        local is_not_desired_filetype = false
        for _, pattern in ipairs(patterns) do -- Checks file extension
          if string.match(filename, pattern) then
            is_not_desired_filetype = true
            break
          end
        end

        return is_not_desired_filetype
      end
      if excluded_fts() then
        print(' No LSP: Excluded Filetype')
        vim.defer_fn(function()
          vim.cmd('echo ""')
        end, 2000)
      else
        vim.cmd('Lazy load nvim-treesitter')
        vim.defer_fn(function()
          if vim.lsp.buf.server_ready() then
            vim.cmd('echo ""')
          else
            vim.cmd('echo ""')
            vim.cmd('LspStart')
            vim.defer_fn(function()
              if not vim.lsp.buf.server_ready() then
                vim.cmd('MasonToolsInstall')
              end
            end, 250)
          end
        end, 250)
      end
    end, 500)
  end,
})

It provides the majority of the functionality I want. @dpetka2001 thank you again for the help and insight.

[avidseeker]

@dpetka2001 answer's works for me, but is there a way to make it detect on filetype rather than *.md extension? As filetype could be set by a modeline or even on an empty buffer.

Why doesn't something like this work?

return not string.match(vim.api.nvim_buf_get_option(0, "filetype"), "markdown")

[iton0]

If you are using nvim 0.10 nvim_buf_get_option() was deprecated. Try this:

return not string.match(vim.bo.filetype, "markdown")

[avidseeker]

Hmm. Same. This doesn't work:

{ "dense-analysis/ale",
cond = function() return not string.match(vim.bo.filetype, "markdown") end,
},

nvim test.md will still load ALE.

[dpetka2001]

I believe this happens because the FileType event happens after the cond gets evaluated. I tried adding print("test") and print(vim.bo.filetype) and it only prints test not the filetype. So, your best solution would be to match against filename extensions, except if I'm missing something else.