lib.mkOption

Creates an Option declaration for use with the module system.

Inputs

Attribute set

containing none or some of the following attributes.

default

Optional default value used when no definition is given in the configuration.

defaultText

Substitute for documenting the default, if evaluating the default value during documentation rendering is not possible.

Can be any nix value that evaluates.

Usage with lib.literalMD or lib.literalExpression is supported

example

Optional example value used in the manual.

Can be any nix value that evaluates.

Usage with lib.literalMD or lib.literalExpression is supported

description

Optional string describing the option. This is required if option documentation is generated.

relatedPackages

Optional related packages used in the manual (see genRelatedPackages in ../nixos/lib/make-options-doc/default.nix).

type

Optional option type, providing type-checking and value merging.

apply

Optional function that converts the option value to something else.

internal

Optional boolean indicating whether the option is for NixOS developers only.

visible

Optional, whether the option and/or sub-options show up in the manual. Use false to hide the option and any sub-options from submodules. Use "shallow" to hide only sub-options. Use "transparent" to hide this option, but not its sub-options. Default: true.

readOnly

Optional boolean indicating whether the option can be set only once.

Examples

mkOption { }
# => Empty option; type = types.anything

mkOption { default = "foo"; }
# => Same as above, with a default value

Noogle detected

• lib.options.mkOption

mkOption =
    {
      default ? null,
      defaultText ? null,
      example ? null,
      description ? null,
      relatedPackages ? null,
      type ? null,
      apply ? null,
      internal ? null,
      visible ? null,
      readOnly ? null,
    }@attrs:
    attrs // { _type = "option"; };