database.py

from flask import Flask, g
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
import json
from passlib.apps import custom_app_context as pwd_context
import random, string
from itsdangerous import(TimedJSONWebSignatureSerializer as Serializer, BadSignature, SignatureExpired)


app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://survey:anything@localhost/survey'
db = SQLAlchemy(app)
ma = Marshmallow(app)

secret_key = ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(32))


class TextPickleType(db.TypeDecorator):

    impl = db.Text()

    def process_bind_param(self, value, dialect):
        if value is not None:
            value = json.dumps(value)

        return value

    def process_result_value(self, value, dialect):
        if value is not None:
            value = json.loads(value)
        return value

class Users(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(32), unique=True, nullable=False)
    password_hash = db.Column(db.String, nullable=False)

    def hash_password(self, password):
        self.password_hash = pwd_context.encrypt(password)

    def verify_password(self, password):
        return pwd_context.verify(password, self.password_hash)

    def generate_auth_token(self, expiration=600):
    	s = Serializer(secret_key, expires_in = expiration)
    	return s.dumps({'id': self.id })

    @staticmethod
    def verify_auth_token(token):
    	s = Serializer(secret_key)
    	try:
    		data = s.loads(token)
    	except SignatureExpired:
    		#Valid Token, but expired
    		return None
    	except BadSignature:
    		#Invalid Token
    		return None
    	user_id = data['id']
    	return user_id


class Survey(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String, nullable=False)
    description = db.Column(db.String)
    questions = db.Column(db.ARRAY(db.String), nullable=False)
    question = db.Column(TextPickleType(), nullable=False)
    body = db.Column(db.String, nullable=False)
    note = db.Column(db.String)
    start_date = db.Column(db.DateTime, nullable=False)
    end_date = db.Column(db.DateTime)

class SurveySchema(ma.ModelSchema):
    class Meta:
        model = Survey


survey_schema = SurveySchema(many=True)


if __name__ == "__main__":
    db.create_all()