Object Oriented Python with Flask Server?

Question

I\'m using Flask to expose some data-crunching code as a web service. I\'d like to have some class variables that my Flask functions can access.

Let me walk you through

Answer 1

The least-coupled solution is to apply the routes at runtime (instead of at load time):

def init_app(flask_app, database_interface, filesystem_interface):
    server = MyServer(database_interface, filesystem_interface)
    flask_app.route('get_data', methods=['GET'])(server.get_data)

This is very testable--just invoke init_app() in your test code with the mocked/faked dependencies (database_interface and filesystem_interface) and a flask app that has been configured for testing (app.config["TESTING"]=True or something like that) and you're all-set to write tests that cover your entire application (including the flask routing).

The only downside is this isn't very "Flasky" (or so I've been told); the Flask idiom is to use @app.route(), which is applied at load time and is necessarily tightly coupled because dependencies are hard-coded into the implementation instead of injected into some constructor or factory method (and thus complicated to test).