spylib 0.3.3

A library to facilitate interfacing with Shopify's API

Shopify Python Library - SPyLib

The Shopify python library or SPyLib, simplifies the use of the Shopify services such as the REST and GraphQL APIs as well as the OAuth authentication. All of this is done asynchronously using asyncio.

Installation

pip install spylib

Contributing

If you want to contribute a small change/feature, the best is to just create a PR with your changes. For bigger changes/features it's best to open an issue first and discuss it to agree on the code organization and overall implementation before spending too much time on the code, unless you want to keep it in your own forked repo.

Setting up the development environment

We use the python poetry package to manage this package. Follow the official instructions to install poetry on your system then once you clone this repository just just need to do the following to install the dependencies from the development environment, as well as install spylib in editable mode:

poetry install

Then you can start monitoring the code for changes and run the test suite this way:

poetry shell
scripts/test_watch.sh

Overview

Token

The token class contains the majority of the logic for communicating with shopify. To use the token class, you must define a child class for the tokens you are using and implement the save and load abstract methods. Your option for child classes are OnlineTokenABC or OfflineTokenABC:

Implement Token Classes

class OfflineToken(OfflineTokenABC):
  async def save(self):
      # Some code to save the token to a database

  @classmethod
  async def load(cls, store_name: str):
      # Some code to load the token from the database

class OnlineToken(OnlineTokenABC):
  async def save(self):
      # Some code to save the token to a database

  @classmethod
  async def load(cls, store_name: str, user_id: str):
      # Some code to load the token from the database

Create Token

Once you have defined these methods, we can create an instance of a token using one of the following:

token = OfflineToken(
  store_name,
  access_token,
  scope
)

token = OnlineToken(
  store_name,
  access_token,
  scope,
  expires_in,
  associated_user_scope,
  associated_user_id
)

Querying Shopify

We can query the store using either the REST endpoint or the GraphQL endpoint:

token.execute_rest(
  goodstatus,
  method,
  debug,
  endpoint
)

token.execute_gql(
  query,
  variables,
  operation_name
)

The REST method takes a goodstatus parameter that is the response from the API that will not trigger an error.

The method can be get, post, put or delete.

Debug is the error that is outputted on failure.

Endpoint is the API endpoint string that we are querying.

OAuth

Rather than reimplementing for each app the Shopify OAuth authentication one can simple get a FastAPI router that provides the install and callback endpoints ready to handle the whole OAuth process. You just need to call init_oauth_router such that:

from spylib.oauth import OfflineToken, OnlineToken, init_oauth_router


async def my_post_install(storename: str, offline_token: OfflineToken):
    """Function handling the offline token obtained at the end of the installation"""
    # Store to database
    pass

async def my_post_login(storename: str, online_token: OnlineToken):
    """Function handling the online token obtained at the end of the user login"""
    # Store to database
    pass

oauth_router = init_oauth_router(
    app_scopes=['write_orders', 'write_products'],
    user_scopes=['read_orders', 'write_products'],
    public_domain='my.app.com',
    private_key='KEY_FOR_OAUTH_JWT',
    post_install=my_post_install,
    post_login=my_post_login,
)

The app_scopes are for the offline token and the user_scopes for the online token. The public_domain is used to set the callback URL used in the OAuth process.

This library uses a JWT encoded nonce to avoid the need for a database or some other mechanism to track the nonce. This JWT has an expiration time and is unique for each OAuth process making it a valid nonce mechanism. The private_key parameter defines the key used to encode and decode this JWT.

The post_install and post_login provide a way to inject functions handling the result of the installation and the login processes respectivaly. They are meant in particular to record the offline and online tokens in your app's database. They can be synchronous or asynchronous functions taking the storename and the token as arguments.