Project: 0x00. AirBnB clone

Intro:

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The goal of the project is to deploy on your server a simple copy of the AirBnB website.
Its a web application composed of:

• A command interpreter to manipulate data without a visual interface, like in a Shell
• A website (the front-end) that shows the final product to everybody: static and dynamic
• A database or files that store data (data = objects)
• An API that provides a communication interface between the front-end and your data (retrieve, create, delete, update them)

Project Description

The first step in building the clone is to put in place a parent class (called BaseModel) to take care of the initialization, serialization and deserialization of future instances. The serialization/deserialization process will have a simple flow:
Instance <-> Dictionary <-> JSON string <-> file.

CLASSES

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Next, we create all the classes used for the AirBnB that inherit from the BaseModel. They include:

• User
• State
• City
• Place
• Review
• Amenity

All our models are located in the AirBnB/ models directory.

BaseModel

Serves as a base model for other classes in the project. The class contains common attributes and methods for all subclasses.
The __init__ method initializes the id, created_at and updated_at attributes If no arguments are passed
A unique id is generated using the uuid library and the current datetime is used as the value for both created_at and updated_at. The instance is then saved to the storage.
The __str__ method returns a string representation of the object.
The save method updates the updated_at attribute with the current datetime and saves the object to the storage.
The to_dict method returns a dictionary representation of the object. The values of updated_at and created_at are converted to string in ISO format and the key __class__ is added with the value being the class name.

User

Defines a class User that inherits from the BaseModel class. The User class contains attributes for email, password, first name, and last name.

State

Defines a class State that inherits from the BaseModel class. The State class contains a single attribute for the name of the state.

Review

Defines a class Review that inherits from the BaseModel class. The Review class contains attributes for place id, user id, and text of the review.

Place

Defines a class Place that inherits from the BaseModel class. The Place class contains attributes for:

• city id
• user id
• name
• description
• number of rooms
• number of bathrooms
• maximum number of guests
• price per night
• latitude
• longitude
• list of amenity ids

City

Defines a class City that inherits from the BaseModel class. The City class contains attributes for state id and name.

Amenity

Defines a class Amenity that inherits from the BaseModel class. The Amenity class contains an attribute for name.

N/B:

The __init__ method of all derived classes calls the __init__ method of the parent class BaseModel using the super() function, which initializes the id, created_at and updated_at attributes. This ensures that all the attributes and methods defined in the BaseModel class are also available in the derived classes as well.

FILE STORAGE

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We then create the first abstracted storage engine of the project.
It is located in the file Air_BnB_clone/models/engine/file_storage.py
This is a well-structured implementation of a file storage system that can serialize instances of classes into a JSON file and deserialize the JSON file back into instances.
The FileStorage class has methods for adding new objects to the storage, saving the storage to a file, reloading the storage from a file, and retrieving the entire storage.
It uses a dictionary __objects to store the instances, where the keys are strings in the format of <class_name>.<id> and the values are the instances.
The location of the JSON file is specified by the __file_path class attribute, which is set to "file.json".
The new method sets a new object in the storage, by creating a string key for the object using its class name and ID, and setting the object as the value.
The save method serializes the objects in the storage into a JSON file.
The reload method deserializes the JSON file back into the storage, creating instances of the appropriate class based on the name stored in the key of each object in the file.
The all method simply returns the __objects dictionary.

THE LINK

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The __init__.py file located in AirBnB_clone/models/__init__.py links our storage engine Air_BnB_clone/models/engine/file_storage.py to all our BaseModel and console.
It creates an instance of the FileStorageclass, which provides an interface to save and load instances to and from a JSON file.
With the reload method, the file storage will attempt to deserialize the JSON file and populate the __objects dictionary with the deserialized instances. This will allow you to access your instances in the future without having to create them again.

THE CONSOLE

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We then create a custom CLI for the AirBnB project, allowing users to interact with the program through a terminal.
It is located at AirBnB_clone/console.py.

How to start it

While in the directory root AirBnB type python console.py to start up the CLI.

Usage

It implements several functionalities in the class HBNBCommand which is a subclass of cmd.Cmd. These functionalities include:

• creating a new instance
• showing an instance
• destroying an instance
• displaying all instances.

The do_create method creates a new instance of a class and saves it.
Example:

(hbnb) create User
65f7ffcb-2f5e-4153-b020-21476f715ac2
(hbnb)

The do_show method displays a string representation of an instance based on its class name and id.
Example:

(hbnb) show User 65f7ffcb-2f5e-4153-b020-21476f715ac2
[User] 65f7ffcb-2f5e-4153-b020-21476f715ac2 
{'id': '65f7ffcb-2f5e-4153-b020-21476f715ac2', 
'created_at': datetime.datetime(2023, 2, 11, 16, 55, 17, 162879), 
'updated_at': datetime.datetime(2023, 2, 11, 16, 55, 17, 162879)}
(hbnb)

The do_destroy method deletes an instance based on its class name and id.
Example:

(hbnb) destroy User 65f7ffcb-2f5e-4153-b020-21476f715ac2
(hbnb) 

The do_all method prints all string representations of instances, filtered by class name if provided.
Example:

(hbnb) all User
["[User] 1e86eedc-774a-48ef-87bd-4f437922b875 
{'id': '1e86eedc-774a-48ef-87bd-4f437922b875', 
'created_at': datetime.datetime(2023, 2, 11, 10, 45, 7, 14132), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 45, 7, 14132)}", 
"[User] cf4f279b-9d5e-45d1-8d8a-50c0e893b0e7 
{'id': 'cf4f279b-9d5e-45d1-8d8a-50c0e893b0e7', 
'created_at': datetime.datetime(2023, 2, 11, 11, 16, 22, 566800), 
'updated_at': datetime.datetime(2023, 2, 11, 11, 16, 22, 566800)}"]
(hbnb)

or without class

(hbnb) all
["[BaseModel] fa6a1c07-2117-4dd1-9019-c5cbaf1a6f03 
{'id': 'fa6a1c07-2117-4dd1-9019-c5cbaf1a6f03', 
'created_at': datetime.datetime(2023, 2, 11, 10, 44, 46, 509581), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 44, 46, 509581)}", 
"[User] 1e86eedc-774a-48ef-87bd-4f437922b875 
{'id': '1e86eedc-774a-48ef-87bd-4f437922b875', 
'created_at': datetime.datetime(2023, 2, 11, 10, 45, 7, 14132), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 45, 7, 14132)}", 
"[Amenity] 4e393861-e21d-4bf0-8ff1-45b83fb02282 
{'id': '4e393861-e21d-4bf0-8ff1-45b83fb02282', 
'created_at': datetime.datetime(2023, 2, 11, 10, 45, 16, 60186), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 45, 16, 60186)}", 
"[Place] 74662458-80c3-4a63-8c4d-fd9fed13e374 
{'id': '74662458-80c3-4a63-8c4d-fd9fed13e374', 
'created_at': datetime.datetime(2023, 2, 11, 10, 46, 27, 541310), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 46, 27, 541310)}", 
"[State] 023850af-9a69-43be-abe2-9ae3b191cf56 
{'id': '023850af-9a69-43be-abe2-9ae3b191cf56', 
'created_at': datetime.datetime(2023, 2, 11, 10, 46, 43, 398415), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 46, 43, 398415)}", 
"[City] 333bc0cc-1a5a-4366-9b48-8b00c7d0183a 
{'id': '333bc0cc-1a5a-4366-9b48-8b00c7d0183a', 
'created_at': datetime.datetime(2023, 2, 11, 10, 46, 54, 284694), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 46, 54, 284694)}", 
"[Review] 815da6cd-508c-4e62-8f5a-2741e6ebfb98 
{'id': '815da6cd-508c-4e62-8f5a-2741e6ebfb98', 
'created_at': datetime.datetime(2023, 2, 11, 10, 47, 3, 904086), 
'updated_at': datetime.datetime(2023, 2, 11, 10, 47, 3, 904086)}", 
"[User] cf4f279b-9d5e-45d1-8d8a-50c0e893b0e7 
{'id': 'cf4f279b-9d5e-45d1-8d8a-50c0e893b0e7', 
'created_at': datetime.datetime(2023, 2, 11, 11, 16, 22, 566800), 
'updated_at': datetime.datetime(2023, 2, 11, 11, 
16, 22, 566800)}"]
(hbnb)

The do_update method updates an instance with new attributes, or creates a new attribute if it doesn't exist.
Example:

(hbnb) update User cf4f279b-9d5e-45d1-8d8a-50c0e893b0e7 first_name John
(hbnb)