Mercurial > hg > configuration
view configuration/config.py @ 21:0fe74db6a56c
a hacky way to do CLI types handlers
author | Jeff Hammel <jhammel@mozilla.com> |
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date | Mon, 26 Mar 2012 14:45:36 -0700 |
parents | dbfabe96187e |
children | 73e72a764c3a |
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#!/usr/bin/env python """ multi-level unified configuration """ import sys import optparse # imports for contigent configuration providers try: import json except ImportError: try: import simplejson as json except ImportError: json = None try: import yaml except ImportError: yaml = None __all__ = ['Configuration', 'configuration_providers'] configuration_providers = [] if json: class JSON(object): extensions = ['json'] def read(self, filename): return json.loads(file(filename).read()) configuration_providers.append(JSON) if yaml: class YAML(object): extensions = ['yml'] def read(self, filename): f = file(filename) config = yaml.load(f) f.close() return config configuration_providers.append(YAML) ### plugins for option types ### TODO: this could use a bit of thought def base_cli(name, value): # CLI arguments args = value.get('flags', ['--%s' % name]) if not args: # No CLI interface return (), {} kw = {'dest': name} help = value.get('help', name) if 'default' in value: kw['default'] = value['default'] # TODO: use default pattern a la # - http://hg.mozilla.org/build/talos/file/c6013a2f09ce/talos/PerfConfigurator.py#l358 # - http://k0s.org/mozilla/hg/bzconsole/file/d5e88dadde69/bzconsole/command.py#l12 help += ' [DEFAULT: %s]' % value['default'] kw['help'] = help kw['action'] = 'store' return args, kw def bool_cli(name, value): args, kw = base_cli(name, value) if value.get('default'): pass # TODO return args, kw def list_cli(name, value): args, kw = base_cli(name, value) # TODO: could use 'extend' # - http://hg.mozilla.org/build/mozharness/file/5f44ba08f4be/mozharness/base/config.py#l41 # TODO: what about nested types? kw['action'] = 'append' return args, kw types = {bool: bool_cli, list: list_cli, None: base_cli} # default class Configuration(object): options = {} def __init__(self, configuration_providers=configuration_providers, types=types): self.config = {} self.configuration_providers = configuration_providers self.types = types def items(self): # TODO: allow options to be a list of 2-tuples return self.options.items() def check(self, config): """check validity of configuration""" # TODO: ensure options in configuration are in self.options unknown_options = [] # TODO: ensure options are of the right type (if specified) def __call__(self, *args): """add items to configuration and check it""" def add(self, config): """update configuration: not undoable""" self.check(config) self.config.update(config) # TODO: option to extend; augment lists/dicts ### methods for optparse ### XXX could go in a subclass def optparse_options(self, parser): """add optparse options to a OptionParser instance""" for key, value in self.items(): handler = self.types[value.get('type')] args, kw = handler(key, value) if not args: # No CLI interface continue parser.add_option(*args, **kw) def parser(self, configuration_provider_option=None, **parser_args): """ return OptionParser for this Configuration instance - configuration_provider_options : option for configuration files [TODO] (also TODO: a special value that equates to the first file extension value for the configuration_providers) - parser_args : arguments to the OptionParser constructor """ if 'description' not in parser_args: parser_args['description'] = getattr(self, '__doc__', '') if 'formatter' not in parser_args: class PlainDescriptionFormatter(optparse.IndentedHelpFormatter): """description formatter for console script entry point""" def format_description(self, description): if description: return description.strip() + '\n' else: return '' parser_args['formatter'] = PlainDescriptionFormatter() parser = optparse.OptionParser(**parser_args) self.optparse_options(parser) return parser def parse(self, args=sys.argv[1:], parser=None): """parse configuration including command line options""" # parse arguments if parser is None: parser = self.parser() options, args = parser.parse_args(args) # return parsed arguments return options, args