Arcane Hooker

I'm a hooker from Silvermoon City. Let me show you the Arcane way to Python

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Hooker is a hooking library that tries to simplify event firing and catching. It gives the ability to plugin creators to create plugins for many different parts, without having to break the logic in separate destinations, if it's not needed. The main features include:

• Event declaration with help message support
• Waterfall events that pass their output as arguments to next hook
• Simple CLI tool to view all defined events of a project and its help messages
• Functions decorators to hook on events
• Dependency requirement for hooks (a hook has to be run before b)
• HOOKER_SCRIPTS environmental variable allows to load additional scripts (aka plugins)
• Wildcard hooks that are fired on all events
• When a hook accepts the __retvals__ argument, the returned values of the previous hooks (and the whole hook functions) will be passed into it as an OrderedDict
• Python 2 compatibility - I'll try to keep that for as long as I can

Terminology:

• Project: A project that uses Hooker
• Plugin: A piece of code that adds functionality to a Project using hooks
• Event: A name for something that Plugins can hook on. It is called on specific times (that the Project author has programmed) so that Plugins can add functionality
• Hook: A function that the Plugin creator wrote and is declared as hook using the @hooker.hook decorator. Contains at least one Event name (or none if its a wildcard hook) and optionally Dependencies
• Dependency: A Hook can declare to be called after a plugin has run. Dependency can include the name(s) of the python module(s) (NOT the function name) that include hooks that need to be run before the Hook

For documentation check the wiki

Installation

pip install -U hooker

Usage

To find defined hooks in a project use python -m hooker <python file/module directory>

Example:

$ py -m hooker example/crypter/crypter.py

pre_open_in: Input file will open. Arguments: path<str>. Return: path<str> - /home/dzervas/Lab/satori/hooker/example/crypter/crypter.py:6
pre_open_out: Output file will open. Arguments: path<str>. Return: path<str> - /home/dzervas/Lab/satori/hooker/example/crypter/crypter.py:7
encrypt: Encrypt data. Arguments: data<bytearray>. Return: data<str> - /home/dzervas/Lab/satori/hooker/example/crypter/crypter.py:8
decrypt: Decrypt data. Arguments: data<bytearray>. Return: data<str> - /home/dzervas/Lab/satori/hooker/example/crypter/crypter.py:9

As a Project Author to use hooker you have to declare an event and then fire it

Example:

# project.py
import hooker

hooker.EVENTS.append("test", "Fired after Hello World is printed")

print("Hello World")
hooker.EVENTS["test"]()

As a Plugin Creator to extend a project using hooker, you have to create a function using the @hooker.hook decorator and define the event you want to hook on:

Example:

# my_plugin.py
import hooker

@hooker.hook("test")
def hello():
    print("Goodbye World")

Now to use the plugin, you either have to import it in the project, or execute the project using the environment variable HOOKER_SCRIPTS as follows:

$ HOOKER_SCRIPTS=my_plugin python project.py

Hello World
Goodbye World

Used in

• Satori - The reason this project exists
• wormnest - A Web Server to hide stuff

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While the code is not a mess, I'm using a fair bit of python magic. The target is to provide the simplest and most convenient API for both project and plugin authors.

If you have a better way to do something, at least open an issue to discuss it, I'm very interested!

Happy Hacking! :)