Command Autoloading

arc support dynamic loading of subcommands via the Command.autoload() method.

This allows you to offer your users to option to extend the functionality of your CLI with their own custom commands.

Command.autoload() can accept an arbitrary number of paths to either files or directories. When given a file, it will attempt to load commands from that file. When given a directory, it will attempt to load every file in that directory. In both cases, if no command is found, it will continue onto the next path rather than erroring.

Example

timers.pycli.py

# /home/user/timers.py
import arc

@arc.command()
def autoload_demo():
    arc.print("I've been autoloaded!")

# cli.py
import arc

@arc.command()
def command():
    ...

command.autoload("/home/users/timers.py")
command()

Now we can run the autoload-demo command, without importing it directly

$ python cli.py autoload-demo
I've been autoladed!

Overwriting Commands

By default, commands that are autloaded can overwrite regular commands.

timers.pycli.py

# /home/user/timers.py
import arc

@arc.command()
def sub():
    arc.print("I've been autoloaded!")

# cli.py
import arc

@arc.command()
def command():
    ...

@command.subcommand()
def sub():
    arc.print("I'm the original")

command.autoload("/home/users/timers.py")
command()

$ python cli.py sub
I've been autoladed!

You can disable this with a configuration option

arc.configure(autoload_overwrite=False)