Info for an Igniter.Mix.Task, returned from the info/2 callback

Configurable Keys

• schema - The option schema for this task, in the format given to OptionParser, i.e [name: :string]. See the schema section for more.
• defaults - Default values for options in the schema.
• required - A list of flags that are required for this task to run.
• positional - A list of positional arguments that this task accepts. A list of atoms, or a keyword list with the option and config. See the positional arguments section for more.
• aliases - A map of aliases to the schema keys.
• composes - A list of tasks that this task might compose.
• installs - A list of dependencies that should be installed before continuing.
• adds_deps - A list of dependencies that should be added to the mix.exs, but do not need to be installed before continuing.
• extra_args? - Whether or not to allow extra arguments. This forces all tasks that compose this task to allow extra args as well.
• example - An example usage of the task. This is used in the help output.

Your task should always use switches and not strict to validate provided options!

Options and Arguments

Command line args are automatically parsed into igniter.args using this struct's configuration.

@impl Igniter.Mix.Task
def igniter(igniter) do
  positional = igniter.args.positional
  options = igniter.args.options
end

If you need to do custom validation or parsing, you can implement Igniter.Mix.Task.parse_argv/1 and return an Igniter.Mix.Task.Args struct. If helpful, the positional_args!/1 and options!/1 macros can be used to parse positional arguments and options/flags using your info configuration.

@impl Igniter.Mix.Task
def parse_argv(argv) do
  {positional, argv_flags} = positional_args!(argv)
  options = options!(argv_flags)

  # custom validation or additional parsing

  %Igniter.Mix.Task.Args{
    argv: argv,
    argv_flags: argv_flags,
    positional: positional,
    options: options
  }
end

Options

The schema is an option parser schema, and OptionParser is used to parse the options, with a few noteable differences.

• The defaults from the defaults option in your task info are applied.
• The :keep type is automatically aggregated into a list.
• The :csv option automatically splits the value on commas, and allows it to be specified multiple times.

Positional Arguments

Each positional argument can provide the following options:

• :optional - Whether or not the argument is optional. Defaults to false.
• :rest - Whether or not the argument consumes the rest of the positional arguments. Defaults to false.

        The value will be converted to a list automatically.