flask.py

import json
from functools import wraps

from flask import request

from utils.exceptions import HttpNotFound
from utils.validators import Required

def require(f):
    @wraps(f)
    def decorated(self):
        required_payload = []

        for key in self.model.__dict__:
            if key.startswith('validate_'):
                validators = self.model.__dict__[key].validators
                for v in validators:
                    if isinstance(v, Required):
                        required_payload.append(key[9:])

        data = {}

        if request.method in ['POST', 'PUT'] and request.data:
            columns = [
                str(c).split('.', 1)[1] \
                for c in self.model.__table__.columns
            ]

            data = json.loads(request.data)

            request.data = json.dumps({
                k: v for k, v in data.items() if k in columns
            })

        if request.method != 'POST':
            return f(self)

        for field in required_payload:
            if field not in data.keys():
                raise HttpNotFound({
                    'error': 'Field %s was not found in payload' % (field)
                })

        return f(self)

    return decorated