How to get information from the "selected item" for a custom function on a picker?

[DominikMendel]

I want to create some tmux functionality where in a file picker, I want to open a new tmux window at the "cursor selected". But, what information, and how, do I get the information under the cursor for the "select" functionality?

For exmaple, if I have a picker :

/foo/bar
/foo/baz (selected)
/foo/bar/baz

How do I get all the "meta data" of the selected entry /foo/baz?

And I want to confirm, I kind of want to achieve this behavior like so:

Snacks.picker.pick('files', {
  actions = {
    before_confirm = function(picker, item)
      vim.print(item) -- But do TMUX stuff here instead
    end,
  },
  win = {
    input = {
      keys = {
        ['<CR>'] = { { 'before_confirm', 'confirm' }, mode = { 'i', 'n' } },
      },
    },
  },
})

I guess I see the picker and item in this example now. I'm assuming item is the selected, but then what is picker?

[drowning-cat]

1. Make sure you have types completion enabled:

   bug: LSP doesn't resolve snacks types #443 (comment)

2. picker is a table that contains information about the state of an opened picker, as well as functions to modify its behavior:

   • picker:set_layout {}
   • picker:focus 'input'
   • picker:action 'toggle_live'
   • ...

Note

picker:set_layout(...) is the same as picker.set_layout(picker, ...).

3. item refers to the item under the cursor when the action is performed. Essentially, it is the currently selected item:

Tip

Press <M-d> when a picker is opened to print the same information.

[drowning-cat]

Simple

Use Snacks.picker.select. It is a replacement for the vim.ui.select (see :help vim.ui.select).

vim.ui.select({
  { text = "tabs", action = "print(1)" },
  { text = "spaces", action = "print(2)" },
}, {
  prompt = "Perform action:",
  format_item = function(item)
    return "I'd like to choose " .. item.text
  end,
}, function(choice)
  if choice then
    load(choice.action)()
  end
end)

Advanced

Create your own source with opts.picker.sources.<custom>:

• How to use the Snacks.picker.smart() and its flags? #1908 (comment)
• feat(picker.scratch): add scratch picker with grep, new and delete keybinds #1019 (comment)

[DominikMendel]

This is very helpful, thank you @drowning-cat.

This select option is great to know about.
A followup question, maybe in a related area.

I'm also looking into extending a keys to a function on the selected option, but I'm not sure if I can do it the same item as mentioned previously?

opts = {
  picker = {
    win = {
      input = {
        keys = {
          ["<c-t>"] = {
            function(picker, item)
              if item then
                Snacks.notify(string.format("Item picked %s", item))
              else
                Snacks.notify("Nothing selected")
              end
            end,
            mode = { "n", "i" },
          },
        },
      },
    },
  },
}

This will always yield Nothing selected. I want to be able to "get the item that is currently selected" and perform actions with the information in item and then close the picker. Is this possible from an already defined picker?
I tested with a few pickers like picker.files.

[drowning-cat]

You forgot to add a picker field:

• opts.picker.win.input.keys
• or opts.picker.sources.<source>.win.input.keys.

[DominikMendel]

Oh sorry @drowning-cat , it's there. I just didn't copy it into GH properly (updated). The function is ran, but my question of how to get the selected item stands.

[drowning-cat]

opts = {
  picker = {
    actions = {
      custom_action = function(picker, item)
        Snacks.notify(string.format("Item picked %s", item))
      end,
    },
    win = {
      input = {
        keys = {
          -- NOTE: Can be overridden by the implicit configuration of a picker
          -- Therefore, prefer using `opts.picker.sources.<source>`
          ["<c-t>"] = { "custom_action", mode = { "n", "i" } },
        },
      },
    },
  },
}