mirror of
https://github.com/Steffo99/cfig.git
synced 2024-12-23 06:34:22 +00:00
130 lines
3.7 KiB
ReStructuredText
130 lines
3.7 KiB
ReStructuredText
##############
|
|
Advanced usage
|
|
##############
|
|
|
|
This page describes some more advanced :mod:`cfig` features that you might be interested in using.
|
|
|
|
|
|
Fail-fast
|
|
=========
|
|
|
|
If your variables are very slow to be resolved, you may want for the :meth:`~cfig.config.Configuration.ProxyDict.resolve` method to raise as soon as a single value fails to resolve.
|
|
|
|
For that purpose, the :meth:`~cfig.config.Configuration.ProxyDict.resolve_failfast` method is provided:
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 4
|
|
|
|
from .mydefinitionmodule import config
|
|
|
|
if __name__ == "__main__":
|
|
config.proxies.resolve_failfast()
|
|
|
|
Please note that the :meth:`~cfig.config.Configuration.ProxyDict.resolve_failfast` method does not raise :exc:`~cfig.errors.BatchResolutionFailure`, but raises the first occurring error instead, so you might want to catch it in this way:
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 4,5,6,7
|
|
|
|
from .mydefinitionmodule import config
|
|
|
|
if __name__ == "__main__":
|
|
try:
|
|
config.proxies.resolve_failfast()
|
|
except cfig.ConfigurationError as err:
|
|
...
|
|
|
|
|
|
Access all resolved variables at once
|
|
=====================================
|
|
|
|
In certain cases, you might want to obtain a :class:`dict` containing all resolved variables, without them being proxied.
|
|
|
|
You may have noticed that both :meth:`~cfig.config.Configuration.ProxyDict.resolve` and :meth:`~cfig.config.Configuration.ProxyDict.resolve_failfast` return a :class:`dict`: that's exactly what you need!
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 2
|
|
|
|
...
|
|
static_cfg = config.proxies.resolve()
|
|
...
|
|
|
|
.. note::
|
|
|
|
Be aware that the :class:`dict` returned will never change, even after a :ref:`reload <Reloading variables>`!
|
|
|
|
|
|
Reloading variables
|
|
===================
|
|
|
|
You might want for the configuration to be reloaded without restarting your application.
|
|
|
|
In that case, you may use the :meth:`~cfig.config.Configuration.ProxyDict.unresolve` method to clear the cached values, and then call :meth:`~cfig.config.Configuration.ProxyDict.resolve` again.
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 2,3
|
|
|
|
...
|
|
config.proxies.unresolve()
|
|
config.proxies.resolve()
|
|
...
|
|
|
|
To reload a single variable, you may use the ``del`` keyword:
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 2
|
|
|
|
...
|
|
del MY_VARIABLE.__wrapped__
|
|
...
|
|
|
|
|
|
Sources selection
|
|
=================
|
|
|
|
If you need further fine-tuning of the places to gather configuration values from, you may specify them via the :attr:`cfig.config.Configuration.sources` collection:
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 2,3,5,6,7,8,9,10
|
|
|
|
import cfig
|
|
import cfig.sources.env
|
|
import cfig.sources.envfile
|
|
|
|
config = cfig.Configuration(sources=[
|
|
cfig.source.env.EnvironmentSource(),
|
|
cfig.source.env.EnvironmentSource(prefix="PROD_"),
|
|
cfig.source.envfile.EnvironmentFileSource(),
|
|
cfig.source.envfile.EnvironmentFileSource(suffix="_PATH"),
|
|
])
|
|
|
|
The specified sources are used in the order they are specified.
|
|
|
|
They may also be altered at runtime, if for some *crazy reason* you need that feature:
|
|
|
|
.. code-block:: python
|
|
:emphasize-lines: 6,7,8
|
|
|
|
import cfig
|
|
import cfig.sources.env
|
|
|
|
config = cfig.Configuration()
|
|
|
|
config.sources.append(
|
|
cfig.source.env.EnvironmentSource()
|
|
)
|
|
|
|
.. note::
|
|
|
|
Already cached variables **won't** be automatically reloaded after changing the sources!
|
|
|
|
|
|
Sources customization
|
|
---------------------
|
|
|
|
If the provided sources aren't enough, you may create a custom class inheriting from :class:`~cfig.sources.base.Source`.
|
|
|
|
.. hint::
|
|
|
|
Since :mod:`cfig.sources` is a namespace package, if you intend to distribute your custom source, you may want to do it by extending the namespace, for an easier developer workflow.
|
|
|
|
|