Serialize Flask-SQLAlchemy Models into JSON

app.py

from flask import Flask, jsonify
from json_serializable import JSONSerializable
from flask_sqlalchemy import SQLAlchemy

# Initialize database instance.
db = SQLAlchemy()

# Create app flask
app = Flask(__name__)
JSONSerializable(app)

# Connected app context with database
with app.app_context():
  db.init_app(app)
  db.create_all()

  
class User(db.Model):
  __tablename__ = 'users'

  uid         = Column(String(), primary_key=True)
  email       = Column(String(), nullable=True, unique=True)
  displayName = Column(String(), nullable=True, unique=True)
  name        = Column(String(), nullable=True)



  def __init__(self, 
          uid             : str, 
          email           : str,
          displayName     : str,
          name            : str,
  ):

      self.uid            = id
      self.email          = email
      self.displayName    = displayName
      self.name           = name
        
  
@app.route('/json')
def simple_json():
  return jsonify(User.query.all())

@app.route('/dict')
def simple_dict():
  return jsonify(ok=True, args=[])

json_serializable.py

import json
import flask
from collections import OrderedDict
from datetime import datetime

try:
    from flask_sqlalchemy.model import Model
except ImportError as e:
    print(str(e))


class JSONEncoder(json.JSONEncoder):

    def default(self, o):

        def recursive(p):
            result = OrderedDict()
            for k in p.keys():
                result[k] = getattr(o, k)

                if isinstance(result[k], dict):
                    result[k] = recursive(result[k])
                if isinstance(result[k], datetime):
                    result[k] = result[k].timestamp()

            return result

        if isinstance(o, Model):
            return dict(recursive(o.__mapper__.c))
        
        return flask.json.JSONEncoder.default(self, o)


def JSONSerializable(app=None, **kwargs):
    if app is not None:
        app.json_encoder = JSONEncoder