Source code for plaster.interfaces

import abc


[docs]class ILoader(metaclass=abc.ABCMeta): """ An abstraction over an source of configuration settings. It is required to implement ``get_sections``, ``get_settings`` and ``setup_logging``. Optionally, it may also implement other :term:`loader protocol` interfaces to provide extra functionality. For example, :class:`plaster.protocols.IWSGIProtocol` which requires ``get_wsgi_app``, and ``get_wsgi_server`` for loading WSGI configurations. Services that depend on such functionality should document the required functionality behind a particular :term:`loader protocol` which custom loaders can implement. :ivar uri: The :class:`plaster.PlasterURL` object used to find the :class:`plaster.ILoaderFactory`. """
[docs] @abc.abstractmethod def get_sections(self): """ Load the list of section names available. """
[docs] @abc.abstractmethod def get_settings(self, section=None, defaults=None): """ Load the settings for the named ``section``. :param section: The name of the section in the config file. If this is ``None`` then it is up to the loader to determine a sensible default usually derived from the fragment in the ``path#name`` syntax of the ``config_uri``. :param defaults: A ``dict`` of default values used to populate the settings and support variable interpolation. Any values in ``defaults`` may be overridden by the loader prior to returning the final configuration dictionary. :returns: A ``dict`` of settings. This should return a dictionary object even if the section is missing. :raises ValueError: If a section name is missing and cannot be determined from the ``config_uri``. """
[docs] @abc.abstractmethod def setup_logging(self, defaults=None): """ Execute the logging configuration defined in the config file. This function should, at least, configure the Python standard logging module. However, it may also be used to configure any other logging subsystems that serve a similar purpose. :param defaults: A ``dict`` of default values used to populate the settings and support variable interpolation. Any values in ``defaults`` may be overridden by the loader prior to returning the final configuration dictionary. """
[docs]class ILoaderFactory(metaclass=abc.ABCMeta):
[docs] @abc.abstractmethod def __call__(self, uri): """ A factory which accepts a :class:`plaster.PlasterURL` and returns a :class:`plaster.ILoader` object. """
[docs]class ILoaderInfo(metaclass=abc.ABCMeta): """ An info object describing a specific :class:`plaster.ILoader`. :ivar scheme: The full scheme of the loader. :ivar protocols: Zero or more supported :term:`loader protocol` identifiers. :ivar factory: The :class:`plaster.ILoaderFactory`. """
[docs] @abc.abstractmethod def load(self, config_uri): """ Create and return an :class:`plaster.ILoader` instance. :param config_uri: Anything that can be parsed by :func:`plaster.parse_uri`. """