40 lines
1.4 KiB
Python
40 lines
1.4 KiB
Python
import importlib
|
|
import click
|
|
|
|
|
|
class LazyGroup(click.Group):
|
|
def __init__(self, *args, lazy_subcommands=None, **kwargs):
|
|
super().__init__(*args, **kwargs)
|
|
# lazy_subcommands is a map of the form:
|
|
#
|
|
# {command-name} -> {module-name}.{command-object-name}
|
|
#
|
|
self.lazy_subcommands = lazy_subcommands or {}
|
|
|
|
def list_commands(self, ctx):
|
|
base = super().list_commands(ctx)
|
|
lazy = sorted(self.lazy_subcommands.keys())
|
|
return base + lazy
|
|
|
|
def get_command(self, ctx, cmd_name):
|
|
if cmd_name in self.lazy_subcommands:
|
|
return self._lazy_load(cmd_name)
|
|
return super().get_command(ctx, cmd_name)
|
|
|
|
def _lazy_load(self, cmd_name):
|
|
# lazily loading a command,
|
|
# first get the module name and attribute name
|
|
import_path = self.lazy_subcommands[cmd_name]
|
|
modname, cmd_object_name = import_path.rsplit(".", 1)
|
|
# do the import
|
|
mod = importlib.import_module(modname)
|
|
# get the Command object from that module
|
|
cmd_object = getattr(mod, cmd_object_name)
|
|
# check the result to make debugging easier
|
|
if not isinstance(cmd_object, click.BaseCommand):
|
|
raise ValueError(
|
|
f"Lazy loading of {import_path} failed by returning "
|
|
"a non-command object"
|
|
)
|
|
return cmd_object
|