python flask request hook

Question

I want to be able to add some data into the request variable in flask for all incoming requests. Is there an easy way to hook into this without having to write this logic into each one of my endpoints?

Answer 1

You may be looking for flask.Flask.before_request.

Also you won't necessarily be able to add data into the request attributes form and args as they are immutable, consider using g which is a thread local.

Example usage:

from flask import Flask, request, g

app = Flask(__name__)

@app.route('/')
def home():
    return g.target + '\n'

@app.before_request
def before_req():
    g.target = request.args.get('target', 'default')

if __name__ == '__main__':
    app.run()

Usage:

$ wget -qO - 'http://localhost:5000/?target=value'
value
$ wget -qO - 'http://localhost:5000/?key=value'
default