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Diffstat (limited to 'websdk/flask/config.py')
| -rw-r--r-- | websdk/flask/config.py | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/websdk/flask/config.py b/websdk/flask/config.py new file mode 100644 index 0000000..67dbf9b --- /dev/null +++ b/websdk/flask/config.py @@ -0,0 +1,169 @@ +# -*- coding: utf-8 -*- +""" + flask.config + ~~~~~~~~~~~~ + + Implements the configuration related objects. + + :copyright: (c) 2011 by Armin Ronacher. + :license: BSD, see LICENSE for more details. +""" + +from __future__ import with_statement + +import imp +import os +import errno + +from werkzeug.utils import import_string + + +class ConfigAttribute(object): + """Makes an attribute forward to the config""" + + def __init__(self, name, get_converter=None): + self.__name__ = name + self.get_converter = get_converter + + def __get__(self, obj, type=None): + if obj is None: + return self + rv = obj.config[self.__name__] + if self.get_converter is not None: + rv = self.get_converter(rv) + return rv + + def __set__(self, obj, value): + obj.config[self.__name__] = value + + +class Config(dict): + """Works exactly like a dict but provides ways to fill it from files + or special dictionaries. There are two common patterns to populate the + config. + + Either you can fill the config from a config file:: + + app.config.from_pyfile('yourconfig.cfg') + + Or alternatively you can define the configuration options in the + module that calls :meth:`from_object` or provide an import path to + a module that should be loaded. It is also possible to tell it to + use the same module and with that provide the configuration values + just before the call:: + + DEBUG = True + SECRET_KEY = 'development key' + app.config.from_object(__name__) + + In both cases (loading from any Python file or loading from modules), + only uppercase keys are added to the config. This makes it possible to use + lowercase values in the config file for temporary values that are not added + to the config or to define the config keys in the same file that implements + the application. + + Probably the most interesting way to load configurations is from an + environment variable pointing to a file:: + + app.config.from_envvar('YOURAPPLICATION_SETTINGS') + + In this case before launching the application you have to set this + environment variable to the file you want to use. On Linux and OS X + use the export statement:: + + export YOURAPPLICATION_SETTINGS='/path/to/config/file' + + On windows use `set` instead. + + :param root_path: path to which files are read relative from. When the + config object is created by the application, this is + the application's :attr:`~flask.Flask.root_path`. + :param defaults: an optional dictionary of default values + """ + + def __init__(self, root_path, defaults=None): + dict.__init__(self, defaults or {}) + self.root_path = root_path + + def from_envvar(self, variable_name, silent=False): + """Loads a configuration from an environment variable pointing to + a configuration file. This is basically just a shortcut with nicer + error messages for this line of code:: + + app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS']) + + :param variable_name: name of the environment variable + :param silent: set to `True` if you want silent failure for missing + files. + :return: bool. `True` if able to load config, `False` otherwise. + """ + rv = os.environ.get(variable_name) + if not rv: + if silent: + return False + raise RuntimeError('The environment variable %r is not set ' + 'and as such configuration could not be ' + 'loaded. Set this variable and make it ' + 'point to a configuration file' % + variable_name) + self.from_pyfile(rv) + return True + + def from_pyfile(self, filename, silent=False): + """Updates the values in the config from a Python file. This function + behaves as if the file was imported as module with the + :meth:`from_object` function. + + :param filename: the filename of the config. This can either be an + absolute filename or a filename relative to the + root path. + :param silent: set to `True` if you want silent failure for missing + files. + + .. versionadded:: 0.7 + `silent` parameter. + """ + filename = os.path.join(self.root_path, filename) + d = imp.new_module('config') + d.__file__ = filename + try: + execfile(filename, d.__dict__) + except IOError, e: + if silent and e.errno in (errno.ENOENT, errno.EISDIR): + return False + e.strerror = 'Unable to load configuration file (%s)' % e.strerror + raise + self.from_object(d) + return True + + def from_object(self, obj): + """Updates the values from the given object. An object can be of one + of the following two types: + + - a string: in this case the object with that name will be imported + - an actual object reference: that object is used directly + + Objects are usually either modules or classes. + + Just the uppercase variables in that object are stored in the config. + Example usage:: + + app.config.from_object('yourapplication.default_config') + from yourapplication import default_config + app.config.from_object(default_config) + + You should not use this function to load the actual configuration but + rather configuration defaults. The actual config should be loaded + with :meth:`from_pyfile` and ideally from a location not within the + package because the package might be installed system wide. + + :param obj: an import name or object + """ + if isinstance(obj, basestring): + obj = import_string(obj) + for key in dir(obj): + if key.isupper(): + self[key] = getattr(obj, key) + + def __repr__(self): + return '<%s %s>' % (self.__class__.__name__, dict.__repr__(self)) |