http://stackoverflow.com/questions/14107066/in-flask-how-can-i-execute-a-before-filter-on-a-particular-pluggable-view

app.py

from flask import Flask, g, request
from flask.views import MethodView
import random

app = Flask(__name__)

NoSQLStore = {}

class NoSQL(object):
    """ fake """
    def query(self, key): 
        return '%s\n' % NoSQLStore.get(key, 'no such key')
    def put(self, key, value):
        NoSQLStore[key] = value

def with_database(fn):
    """ Decorator for functions, that need database access.
        NoSQL object will be stored under ``g.db``. 
    """
    def connect_and_close(*args, **kwargs):
        g.db = NoSQL()
        __result = fn(*args, **kwargs)
        # a real database should be ``closed()`` here
        return __result
    return connect_and_close

class StoreAPI(MethodView):
    
    @with_database
    def get(self):
        return g.db.query(request.args.get('key'))

    @with_database
    def post(self):
        key, value = str(random.randint(0, 1000)), str(random.randint(0, 1000))
        g.db.put(key, value)
        return 'set %s => %s\n' % (key, value)

@app.route('/')
@with_database # uncomment this to mak
def index():
    # this should raise an exception, since db object is not in the 
    # request-bound ``g`` object
    return g.db.query('xyz')

app.add_url_rule('/store', view_func=StoreAPI.as_view('store'))

if __name__ == "__main__":
    app.run(debug=True)