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