demo_pythonanywhere_com.py

#!/usr/bin/env python3
# This script is deployed on thomaxxl.pythonanywhere.com
#
# This is a demo application to demonstrate the functionality of the safrs REST API
# The script depends on
# $ pip install flask_cors
# It can be ran standalone like this:
# $ python demo_relationship.py [Listener-IP]
#
# This will run the example on http://Listener-Ip:5000
#
# - A database is created and items are added
# - A rest api is available
# - swagger2 documentation is generated
# - jsonapi-admin pages are served
#
# All sorts of customizations are applied to the exposed objects
# The explanation can be found on the github wiki (https://github.com/thomaxxl/safrs/wiki)
#
import sys
import os
import datetime
import hashlib
from flask import Flask, redirect, send_from_directory
from flask_sqlalchemy import SQLAlchemy
from flask_cors import CORS
from safrs import SafrsApi  # api factory
from safrs import SAFRSBase  # db Mixin
from safrs import SAFRSFormattedResponse
from safrs import jsonapi_attr
from safrs import jsonapi_rpc  # rpc decorator
from safrs.api_methods import startswith, search  # rpc methods
from functools import wraps
from pathlib import Path

# This html will be rendered in the swagger UI
description = """
<a href=http://jsonapi.org>Json:API</a> compliant API built with https://github.com/thomaxxl/safrs <br/>
- <a href="https://github.com/thomaxxl/safrs/blob/master/examples/demo_pythonanywhere_com.py">Source code of this page</a><br/>
- <a href="/ja/index.html">reactjs+redux frontend</a>
- <a href="https://editor.swagger.io/?url=https://thomaxxl.pythonanywhere.com/api/swagger.json">Swagger2 Editor</a> (updates can be added with the SafrsApi "custom_swagger" argument)
"""

db = SQLAlchemy()

# SQLAlchemy Mixin Superclass with multiple inheritance
class BaseModel(SAFRSBase, db.Model):
    __abstract__ = True
    # Add startswith methods so we can perform lookups from the frontend
    SAFRSBase.search = search
    db_commit = False

class DocumentedColumn(db.Column):
    """
    The class attributes are used for the swagger
    """

    description = "My custom column description"
    swagger_type = "string"
    swagger_format = "string"
    name_format = "filter[{}]"  # Format string with the column name as argument
    required = False
    default_filter = ""
    sample = "my custom value"


# Customized relationships
def hiddenRelationship(*args, **kwargs):
    """
    To hide a relationship, set the expose attribute to False
    """
    relationship = db.relationship(*args, **kwargs)
    relationship.expose = False
    return relationship


# SQLA models that will be exposed
friendship = db.Table(
    "friendships",
    db.metadata,
    db.Column("friend_a_id", db.Integer, db.ForeignKey("People.id"), primary_key=True),
    db.Column("friend_b_id", db.Integer, db.ForeignKey("People.id"), primary_key=True),
)


class Book(BaseModel):
    """
    description: My book description
    """

    __tablename__ = "Books"
    id = db.Column(db.String, primary_key=True)
    title = db.Column(db.String, default="")
    reader_id = db.Column(db.Integer, db.ForeignKey("People.id"))
    author_id = db.Column(db.Integer, db.ForeignKey("People.id"))
    publisher_id = db.Column(db.Integer, db.ForeignKey("Publishers.id"))
    publisher = db.relationship("Publisher", back_populates="books", cascade="save-update, delete")
    reviews = db.relationship("Review", backref="book", cascade="save-update, delete")
    published = db.Column(db.Time)


class Person(BaseModel):
    """
    description: My person description
    """

    __tablename__ = "People"
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String, default="John Doe")
    email = db.Column(db.String, default="")
    comment = DocumentedColumn(db.Text, default="my empty comment")
    dob = db.Column(db.Date)
    books_read = db.relationship("Book", backref="reader", foreign_keys=[Book.reader_id], cascade="save-update, merge")
    books_written = db.relationship("Book", backref="author", foreign_keys=[Book.author_id])
    reviews = db.relationship("Review", backref="reader", cascade="save-update, delete")
    employer_id = db.Column(db.Integer, db.ForeignKey("Publishers.id"))
    employer = hiddenRelationship("Publisher", back_populates="employees", cascade="save-update, delete")
    _password = db.Column(db.String, default="")  # hidden column
    friends = db.relationship(
        "Person", secondary=friendship, primaryjoin=id == friendship.c.friend_a_id, secondaryjoin=id == friendship.c.friend_b_id
    )

    @jsonapi_attr
    def password(self):
        """---
        "_password" is hidden because of the "_" prefix, provide a custom attribute "password" the Person fields
        """
        return "hidden, check _password"

    @password.setter
    def password(self, val):
        """
        Allow setting _password
        """
        self._password = hashlib.sha256(val.encode("utf-8")).hexdigest()

    # Following methods are exposed through the REST API
    @jsonapi_rpc(http_methods=["POST"])
    def send_mail(self, email=""):
        """
        description : Send an email
        args:
            email: test email
        parameters:
            - name : my_query_string_param
              default : my_value
        """
        content = f"Mail to {self.name} : {email}\n"
        with open("/tmp/mail.txt", "a+") as mailfile:
            mailfile.write(content)
        return {"output": f"sent {content}"}

    @classmethod
    @jsonapi_rpc(http_methods=["POST"])
    def my_rpc(cls, *args, **kwargs):
        """
        pageable: false
        parameters:
            - name : my_query_string_param
              default : my_value
        args:
            email: test email
        """
        o1 = cls.query.first()
        o2 = cls.query.first()
        o1.friends.append(o2)
        data = [o1, o2]
        # build a jsonapi response object
        response = SAFRSFormattedResponse(data, {}, {}, {}, 1)
        return response


class Publisher(BaseModel):
    """
    description: My publisher description
    ---
    demonstrate custom (de)serialization in __init__ and to_dict
    """

    __tablename__ = "Publishers"
    id = db.Column(db.Integer, primary_key=True)  # Integer pk instead of str
    name = db.Column(db.String, default="")
    # books = db.relationship("Book", back_populates="publisher", lazy="dynamic")
    books = db.relationship("Book", back_populates="publisher")
    employees = hiddenRelationship(Person, back_populates="employer")

    def __init__(self, *args, **kwargs):
        custom_field = kwargs.pop("custom_field", None)
        SAFRSBase.__init__(self, **kwargs)

    def to_dict(self):
        result = SAFRSBase.to_dict(self)
        result["custom_field"] = "some customization"
        return result

    @classmethod
    def filter(cls, arg):
        """
        Sample custom filtering, override this method to implement custom filtering
        using the sqlalchemy orm

        This method will be called when the filter= url query argument is provided, eg.
        GET /Publishers/?filter=some_filter

        you can use the argument to create custom filtering, f.i.
        cls.query.filter_by(name=arg)
        """
        print(arg)
        return {"provided": arg}

    @jsonapi_attr
    def stock(self):
        """
        default: 30
        ---
        Custom Attribute that will be shown in the book swagger
        """
        return 100


class Review(BaseModel):
    """
    description: Review description
    """

    __tablename__ = "Reviews"
    book_id = db.Column(db.String, db.ForeignKey("Books.id"), primary_key=True)
    reader_id = db.Column(db.Integer, db.ForeignKey("People.id", ondelete="CASCADE"), primary_key=True)
    review = db.Column(db.String, default="")
    created = db.Column(db.DateTime, default=datetime.datetime.now())
    http_methods = {"GET", "POST"}  # only allow GET and POST


# API app initialization:
# Create the instances and exposes the classes
def start_api(swagger_host="0.0.0.0", PORT=None):

    with app.app_context():
        db.init_app(app)
        db.create_all()
        custom_swagger = {
            "info": {"title": "My Customized Title"},
            "securityDefinitions": {"ApiKeyAuth": {"type": "apiKey", "in": "header", "name": "My-ApiKey"}},
        }  # Customized swagger will be merged

        api = SafrsApi(
            app,
            host=swagger_host,
            port=PORT,
            prefix=API_PREFIX,
            custom_swagger=custom_swagger,
            schemes=["http", "https"],
            description=description,
        )

        
        # populate the database
        NR_INSTANCES = 100
        for i in range(NR_INSTANCES):
            reader = Person(name="Reader " + str(i), email="reader@email" + str(i), password=str(i))
            author = Person(name="Author " + str(i), email="author@email" + str(i), password=str(i))
            book = Book(title="book_title" + str(i))
            review = Review(reader_id=2 * i + 1, book_id=book.id, review=f"review {i}")
            publisher = Publisher(name="publisher" + str(i))
            publisher.books.append(book)
            reader.books_read.append(book)
            author.books_written.append(book)
            reader.friends.append(author)
            author.friends.append(reader)
            if i % 20 == 0:
                reader.comment = ""
            for obj in [reader, author, book, publisher, review]:
                db.session.add(obj)

            db.session.commit()

        for model in [Person, Book, Review, Publisher]:
            # Create an API endpoint
            api.expose_object(model)

app = Flask("SAFRS Demo App")

# app routes
@app.route("/ja")  # React jsonapi frontend
@app.route("/ja/<path:path>", endpoint="jsonapi_admin")
def send_ja(path="index.html"):
    return send_from_directory(Path(__file__).parent.parent / "jsonapi-admin/build", path)


@app.route("/swagger_editor/<path:path>", endpoint="swagger_editor")
def send_swagger_editor(path="index.html"):
    return send_from_directory(Path(__file__).parent.parent / "swagger-editor", path)


@app.route("/")
def goto_api():
    return redirect(API_PREFIX)

app.secret_key = "not so secret"
app.config.update(SQLALCHEMY_DATABASE_URI=f"sqlite:///", DEBUG=True)  # DEBUG will also show safrs log messages + exception messages
cors = CORS(app, resources={r"/api/*": {"origins": "*"}})
API_PREFIX = "/api"
HOST = "thomaxxl.pythonanywhere.com"
PORT = 5000

if __name__ == "__main__":
    if len(sys.argv) > 1:
        HOST = sys.argv[1]
    if len(sys.argv) > 2:
        PORT = int(sys.argv[2])
    start_api(HOST, PORT)
    app.run(host=HOST, port=PORT, threaded=False)
else:
    start_api(HOST, PORT)