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Diffstat (limited to 'cli_helpers/config.py')
| -rw-r--r-- | cli_helpers/config.py | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/cli_helpers/config.py b/cli_helpers/config.py new file mode 100644 index 0000000..3d6cb16 --- /dev/null +++ b/cli_helpers/config.py @@ -0,0 +1,270 @@ +# -*- coding: utf-8 -*- +"""Read and write an application's config files.""" + +from __future__ import unicode_literals +import io +import logging +import os + +from configobj import ConfigObj, ConfigObjError +from validate import ValidateError, Validator + +from .compat import MAC, text_type, UserDict, WIN + +logger = logging.getLogger(__name__) + + +class ConfigError(Exception): + """Base class for exceptions in this module.""" + pass + + +class DefaultConfigValidationError(ConfigError): + """Indicates the default config file did not validate correctly.""" + pass + + +class Config(UserDict, object): + """Config reader/writer class. + + :param str app_name: The application's name. + :param str app_author: The application author/organization. + :param str filename: The config filename to look for (e.g. ``config``). + :param dict/str default: The default config values or absolute path to + config file. + :param bool validate: Whether or not to validate the config file. + :param bool write_default: Whether or not to write the default config + file to the user config directory if it doesn't + already exist. + :param tuple additional_dirs: Additional directories to check for a config + file. + """ + + def __init__(self, app_name, app_author, filename, default=None, + validate=False, write_default=False, additional_dirs=()): + super(Config, self).__init__() + #: The :class:`ConfigObj` instance. + self.data = ConfigObj() + + self.default = {} + self.default_file = self.default_config = None + self.config_filenames = [] + + self.app_name, self.app_author = app_name, app_author + self.filename = filename + self.write_default = write_default + self.validate = validate + self.additional_dirs = additional_dirs + + if isinstance(default, dict): + self.default = default + self.update(default) + elif isinstance(default, text_type): + self.default_file = default + elif default is not None: + raise TypeError( + '"default" must be a dict or {}, not {}'.format( + text_type.__name__, type(default))) + + if self.write_default and not self.default_file: + raise ValueError('Cannot use "write_default" without specifying ' + 'a default file.') + + if self.validate and not self.default_file: + raise ValueError('Cannot use "validate" without specifying a ' + 'default file.') + + def read_default_config(self): + """Read the default config file. + + :raises DefaultConfigValidationError: There was a validation error with + the *default* file. + """ + if self.validate: + self.default_config = ConfigObj(configspec=self.default_file, + list_values=False, _inspec=True, + encoding='utf8') + valid = self.default_config.validate(Validator(), copy=True, + preserve_errors=True) + if valid is not True: + for name, section in valid.items(): + if section is True: + continue + for key, value in section.items(): + if isinstance(value, ValidateError): + raise DefaultConfigValidationError( + 'section [{}], key "{}": {}'.format( + name, key, value)) + elif self.default_file: + self.default_config, _ = self.read_config_file(self.default_file) + + self.update(self.default_config) + + def read(self): + """Read the default, additional, system, and user config files. + + :raises DefaultConfigValidationError: There was a validation error with + the *default* file. + """ + if self.default_file: + self.read_default_config() + return self.read_config_files(self.all_config_files()) + + def user_config_file(self): + """Get the absolute path to the user config file.""" + return os.path.join( + get_user_config_dir(self.app_name, self.app_author), + self.filename) + + def system_config_files(self): + """Get a list of absolute paths to the system config files.""" + return [os.path.join(f, self.filename) for f in get_system_config_dirs( + self.app_name, self.app_author)] + + def additional_files(self): + """Get a list of absolute paths to the additional config files.""" + return [os.path.join(f, self.filename) for f in self.additional_dirs] + + def all_config_files(self): + """Get a list of absolute paths to all the config files.""" + return (self.additional_files() + self.system_config_files() + + [self.user_config_file()]) + + def write_default_config(self, overwrite=False): + """Write the default config to the user's config file. + + :param bool overwrite: Write over an existing config if it exists. + """ + destination = self.user_config_file() + if not overwrite and os.path.exists(destination): + return + + with io.open(destination, mode='wb') as f: + self.default_config.write(f) + + def write(self, outfile=None, section=None): + """Write the current config to a file (defaults to user config). + + :param str outfile: The path to the file to write to. + :param None/str section: The config section to write, or :data:`None` + to write the entire config. + """ + with io.open(outfile or self.user_config_file(), 'wb') as f: + self.data.write(outfile=f, section=section) + + def read_config_file(self, f): + """Read a config file *f*. + + :param str f: The path to a file to read. + """ + configspec = self.default_file if self.validate else None + try: + config = ConfigObj(infile=f, configspec=configspec, + interpolation=False, encoding='utf8') + except ConfigObjError as e: + logger.warning( + 'Unable to parse line {} of config file {}'.format( + e.line_number, f)) + config = e.config + + valid = True + if self.validate: + valid = config.validate(Validator(), preserve_errors=True, + copy=True) + if bool(config): + self.config_filenames.append(config.filename) + + return config, valid + + def read_config_files(self, files): + """Read a list of config files. + + :param iterable files: An iterable (e.g. list) of files to read. + """ + errors = {} + for _file in files: + config, valid = self.read_config_file(_file) + self.update(config) + if valid is not True: + errors[_file] = valid + return errors or True + + +def get_user_config_dir(app_name, app_author, roaming=True, force_xdg=True): + """Returns the config folder for the application. The default behavior + is to return whatever is most appropriate for the operating system. + + For an example application called ``"My App"`` by ``"Acme"``, + something like the following folders could be returned: + + macOS (non-XDG): + ``~/Library/Application Support/My App`` + Mac OS X (XDG): + ``~/.config/my-app`` + Unix: + ``~/.config/my-app`` + Windows 7 (roaming): + ``C:\\Users\\<user>\\AppData\\Roaming\\Acme\\My App`` + Windows 7 (not roaming): + ``C:\\Users\\<user>\\AppData\\Local\\Acme\\My App`` + + :param app_name: the application name. This should be properly capitalized + and can contain whitespace. + :param app_author: The app author's name (or company). This should be + properly capitalized and can contain whitespace. + :param roaming: controls if the folder should be roaming or not on Windows. + Has no effect on non-Windows systems. + :param force_xdg: if this is set to `True`, then on macOS the XDG Base + Directory Specification will be followed. Has no effect + on non-macOS systems. + + """ + if WIN: + key = 'APPDATA' if roaming else 'LOCALAPPDATA' + folder = os.path.expanduser(os.environ.get(key, '~')) + return os.path.join(folder, app_author, app_name) + if MAC and not force_xdg: + return os.path.join(os.path.expanduser( + '~/Library/Application Support'), app_name) + return os.path.join( + os.path.expanduser(os.environ.get('XDG_CONFIG_HOME', '~/.config')), + _pathify(app_name)) + + +def get_system_config_dirs(app_name, app_author, force_xdg=True): + r"""Returns a list of system-wide config folders for the application. + + For an example application called ``"My App"`` by ``"Acme"``, + something like the following folders could be returned: + + macOS (non-XDG): + ``['/Library/Application Support/My App']`` + Mac OS X (XDG): + ``['/etc/xdg/my-app']`` + Unix: + ``['/etc/xdg/my-app']`` + Windows 7: + ``['C:\ProgramData\Acme\My App']`` + + :param app_name: the application name. This should be properly capitalized + and can contain whitespace. + :param app_author: The app author's name (or company). This should be + properly capitalized and can contain whitespace. + :param force_xdg: if this is set to `True`, then on macOS the XDG Base + Directory Specification will be followed. Has no effect + on non-macOS systems. + + """ + if WIN: + folder = os.environ.get('PROGRAMDATA') + return [os.path.join(folder, app_author, app_name)] + if MAC and not force_xdg: + return [os.path.join('/Library/Application Support', app_name)] + dirs = os.environ.get('XDG_CONFIG_DIRS', '/etc/xdg') + paths = [os.path.expanduser(x) for x in dirs.split(os.pathsep)] + return [os.path.join(d, _pathify(app_name)) for d in paths] + + +def _pathify(s): + """Convert spaces to hyphens and lowercase a string.""" + return '-'.join(s.split()).lower() |