Looker.nvim

A basic neovim plugin to lookup information in an arbitrary file, and optionally insert it in the current buffer at the cursor.
For instance, I use it to search a bibtex/biblatex file and insert a selected citation key in a markdown file. In fact, this functionality is included as the Bib command So this plugin can be simply used to select and insert bibtex citations. However, the builtin bib command also serves as an example of how to implement your own custom select and insert commands.

Installation and configuration

Install and configure with lazy.nvim

To use the Bib command:

{
   'drgo/lookernvim',
   ft = { 'markdown' },
   opts = {
      bib = {
        search_file = '/Users/drgo/local/writing/refs/vdec.bib',
        close_on_selection = true
      }
    },
},

None of the options is mandatory.

Usage

Bib

• In a markdown file, position the cursor wherever you want to insert the citation.
• In the command prompt, type Bib filename to open a floating window containing the file (or the default bib file if filename is omitted).
• search for citations to insert and press enter anywhere within the text of a citation to insert its key in your document using pandoc markdown citation syntax.

Custom lookup

• The easiest way is to define your own custom user command in your nvim settings file, by providing a custom search_specs table indexed by a key that will be then used as the subcommand.for instance, this is how the builtin Bib command can be defined as a table within the opts table with its key functioning as the command name:

{
   'drgo/lookernvim',
   ft = { 'markdown' },
   opts = {
		bib = {
			search_file = '',
			record_marker = "@",
			extract_id_regex = "{(.+),",
			id_format = "[@{%s};]",
			close_on_selection = true,
		},
    },
},

to invoke the command, type Lookup cmdname args (e.g., Lookup bib).

Alternatively, you could define a standard user command For example, this is how the bib command is created:

vim.api.nvim_create_user_command("Bib", 'Lookup bib', { nargs = '?', complete = 'file' })

The custom lookup table (called search_spec) should have the following entries:

• searchfile: path to a file to open by default (when no file is specified in the lookup command).
• record_marker: string used to find the text to insert, e.g., in a bibtex file, @ marks the citation key.
• extract_id_regex: a regex used to extract the text to be inserted. E.g., this regex "{(.+)," extract the citation key which is any text between { and , following an @articletype.
• id_format: how to format the extracted text for insertion. E.g., [@{%s};] defines that the citation key should be inserted between [@{ and };].
• close_on_selection: if true, the window will close after pressing enter. Default is true.

Commands

Bib [filename] opens filename for searching. If filename is not specified, or if filename is omitted, the default file specified in the configuration under opts.bibfile.

Lookup subcommand [arg] The Lookup accepts either 1 or 2 arguments. If 1 argument is specified, it's interpreted as command if it is string or as search_spec table if it is a table. if 2 arguments are specified, the first must be a valid subcommand name (valid entry in the opts table) and the second is a path to file to be opened for searching.

Limitations

• inserts one entry at a time.

License

MIT License

Copyright (c) 2023 Salah Mahmud