itay-bardugo-flask-version 0.0.2

a package to handle flask routes endpoints by versions

FlaskVersion

install

pip install flask_version -U

Brief

FlaskVersion is a package that helps handle endpoints versions.

What it solves

assume we have the route /api/<version>/output/print

which returns "Hello" to the client.

with Flask it equals to

@app.route("/api/<verrsion>/output/print")
def print():
    return "Hello"

as we can see, <version> is a variable which describes our route version. it can be 1.0, 1.1, 1.2 etc...

what if our server is already serves clients that ask for this route in version 1.0, but, we want to add an extra feature to this route, which will be visible only in version 1.1

we can define a new route for this problem:

@app.route("/api/<verrsion>/output/print_new")
def print():
    return "Hello new feature!"

but we dont want to add new routes for each new feature.

it will be hard to maintain our endpoints and can be a little bit confusing.

this is what FlaskVersion was built for!

FlaskVersion manages your endpoints by linking each method to one or more version in a few simple steps!

• Easy to use
• Easy to maintain

How to use

All you need to do is:

1. define a callable which returns the current request version before each request

#  main_routes.py
from flask_version import register_version_getter

# set g.version to use it in our app
@app.url_value_preprocessor
def dependencies(endpoint, values):
    if values:
        g.version = values.pop("version", "1.2")


# init data before request
@app.before_request
def before_each_request():
    # register our version detector into flask_version component
    @register_version_getter
    def version_detector():
        return g.version # i.g 1.2 (the newest version)

2. tell to FlaskVersion to apply versions on specific route

# ouput_routes.py
from flask_version import dispatch
@app.route("/api/<verrsion>/output/print")
@dispatch # the dispatch decorator tells to FlaskVersion that this method supports older versions
def print():
    # this is the most updated method(latest version).
    #the old versions will be defined in other place
    return "Hello new feature!"

3. set the older versions

#versions/print.py (important: its called print.py becuase we used @dispatch on print() function
# please note: the structrue is
# {specific_routes_folder}/versions/{function_name}.py
from flask_version import apply_version

# this decorator tells to FlaskVersion to apply old() on version "1.0" and "1.1"
@apply_version("1.0")
@apply_version("1.1")
def old():
    return "i am the old version of this route"

Thats it, FlaskVersion does the job for you and it will route to your correct endpoint according to the version input

Structure

basically, it does not matter how you structed your project. you just have to make sure to follow this structure and FlaskVersion will work correctly. The main idea is to create a new versions folder (with an _init_.py) at the same path where you defined

@app.route("/route/to/some/action")
@dispatch
def action():
    pass

and then, create a file inside versions with the same name (in this case action.py), the inside this file, just create your old versions of your endpoint

Example to Structre A:

+-- project
|   +-- main_routes.py
|   +-- output_routes.py
|   +-- versions
|       +-- print.py

Example to Structre B:

+-- project
|   +-- main_routes.py
|   +-- blueprints
|       +-- output
|           +-- routes.py
|           +-- versions
|               +-- {function_name that @dispatch was applyed on it}.py
|       +-- user
|           +-- routes.py
|           +-- versions
|               +-- {function_name that @dispatch was applyed on it}.py

License

MIT