diff --git a/punx/plugin_validations/__init__.py b/punx/plugin_validations/__init__.py new file mode 100644 index 0000000..6c9187a --- /dev/null +++ b/punx/plugin_validations/__init__.py @@ -0,0 +1,2 @@ +from ._core import ValidationPluginBase +from .root import * diff --git a/punx/plugin_validations/_core.py b/punx/plugin_validations/_core.py new file mode 100644 index 0000000..c5db998 --- /dev/null +++ b/punx/plugin_validations/_core.py @@ -0,0 +1,76 @@ +""" +Python plugin loading system. + +# from: https://gist.github.com/will-hart/5899567 +# a simple Python plugin loading system +# see: http://stackoverflow.com/questions/14510286/plugin-architecture-plugin-manager-vs-inspecting-from-plugins-import +""" + +# import imp +# import pathlib + + +# def install_user_plugin(plugin_file): +# """ +# Install plugin(s) from a Python file. +# Potentially dangerous since this is an import of a user-created file. +# """ +# plugin = pathlib.Path(plugin_file).absolute() +# if not plugin.exists(): +# raise FileExistsError(plugin_file) + +# module_name = plugin.stem + +# fp, path, desc = imp.find_module(module_name, [str(plugin.parent)]) +# imp.load_module(module_name, fp, path, desc) + + +class PluginMounter(type): + """ + Register and initiate all plugins subclassed from PluginBase. + Acts as a metaclass which creates anything inheriting from PluginBase. + A plugin mount point derived from: + http://martyalchin.com/2008/jan/10/simple-plugin-framework/ + """ + + def __init__(cls, name, bases, attrs): + """Called when a PluginBase derived class is imported.""" + + if not hasattr(cls, 'plugins'): + # Called when the metaclass is first instantiated + cls.plugins = [] + else: + # Called when a plugin class is imported + cls._enroll(cls) + + def _enroll(cls, plugin): + """Add the plugin to the plugin list and perform any registration logic""" + + # create a plugin instance and store it + instance = plugin() + + # save the plugin reference + cls.plugins.append(instance) + + # apply plugin logic as defined by the plugin + instance.register() + + def register(self): + raise NotImplementedError( + "MUST define 'register()' method in subclass." + ) + + +class ValidationPluginBase(metaclass=PluginMounter): + """A plugin which must provide a `register()` method.""" + + def __str__(self): + return f"Validator: {self.__class__.__name__}" + + def action(self): + """ + The `action()` method describes the plugin's action(s). + """ + raise NotImplementedError( + "MUST define 'action()' method in subclass." + ) diff --git a/punx/plugin_validations/root.py b/punx/plugin_validations/root.py new file mode 100644 index 0000000..07573c3 --- /dev/null +++ b/punx/plugin_validations/root.py @@ -0,0 +1,9 @@ +from ._core import ValidationPluginBase + + +class FileRoot(ValidationPluginBase): + def register(self): + print(f"register: {__file__}::{self.__class__.__name__}") + + def action(self): + print(f"action: {__file__}::{self.__class__.__name__}")