jhonaRiver / hbnb_evolution

HBNB Solution Part 1

This solution successfully implements the repository pattern. It passes the tests provided in the /hbnb/part1/tests directory.

Some things to note

• Doesn't implement the place_amenities endpoints yet.
• The repositories impletented are FileRepository and MemoryRepository, and also has a placeholder for a DBRepository.
• The MemoryRepository doesn't persists the data between runs.
• The FileRepository persists the data in a JSON file by default called data.json.
• It was designed at first to work with memory just to test the tests.

What you need to know about the solution?

• The repositories has a base class called Repository that has the methods that the repositories should implement. The class itself is an abstract class, and all the methods are abstract methods.
• • The methods are: get, get_all, reload, save, update, delete.
• The models has a base class called Base which is an abstract class, it contains three types of methods:
• • @abstractmethods - methods that the class that inherits from Base should implement. The methods are: to_dict
• • @classmethods - This methods are: get, get_all, delete. The logic for these methods is the same for all the models, so it was implemented in the Base class.
• • @staticabstractmethods - methods that the class that inherits from Base should implement, but are static methods. The methods are: create, update.

Tip

You can preload the persistence layer selected via the reload method in the Repository class. This method is called in the __init__ method of the Repository class.

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Important

The tests won't pass if there isn't a dummy country created, for example MemoryRepository on the reload function creates a dummy UY country via the reload method which also calls the populate_db function in the utils/populate.py file.

MVC

The solution is divided into four main parts: Models, Controllers, and Persistence, but not uses Views because it is just a REST API.

• In the controllers package you will find the logic for the API endpoints.
• In the models package you will find the classes that represent the data.
• In the routes package you will find the routes for the API, which are routes that call the controllers.
• In the persistence package you will find the repositories that handle the data.

How the solution works?

The application is built using the factory pattern. The create_app function in the src/__init__.py file creates the application and returns it. The function accepts a config object which is used to configure the application. It registers the routes, the error handlers, cors, and then returns the application.

To run the application you can simply run the app object returned by the create_app function just like the hbnb.py file does. Or you can run the manage.py file, which uses the Flask CLI, with python manage.py run to run the application.

The routes are divided into Blueprints and are registered in the create_app function mentioned above. The routes are located in the src/routes directory.

The routes defined in the files use the controllers to handle the requests. The controllers are in the src/controllers directory.

Then the controllers queries the models to retrieve or save the data. The models are in the src/models directory.

And the models use the current selected repository to handle the data. The repositories are in the src/persistence directory. The src/persistence/__init__.py exports a db object that is the current selected repository.

So, the flow is like this:

Request -> Route -> Controller -> Model -> Repository
(then all the way back)
Response <- Route <- Controller <- Model <- Repository

You can choose the repository you want to use by setting the REPOSITORY_TYPE environment variable to memory, file, or db. The default is memory.

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Just to mention, there is a utils package that for now contains only two files, constants.py and populate.py. The constants.py file contains the constants used in the application, and the populate.py file contains the logic to populate the database with some data.

You can change the constants arbitrarily.

How to run

To run the solution first install the requirements with pip install -r requirements.txt. Then there is a few ways to run it:

• Run the manage.py file with the command python manage.py run and specify flags like --port {port} --host {host} if you want to run it in a different port or host.
• Run the hbnb.py. This file calls a function before running the app that will populate the database with some data.
• Build and run the Dockerfile.