Weather Report

Motivation/ Background

Current weather report mobile applications are heavily bundles with various functionalities that are filled with membership, advertisements, or payments. They take up a lot more than needed storage space and memory in our device. In this project, in order to practice and examine my ability of developing mobile applications, I decide to develop a light weight and user friendly online mobile applications to fill the need of simple and original weather report application.

APP Explanation

Features

My APP includes a number of features. 1. Sign Up: The application uses a online database to store the key information of a user and let users to register an account to keep track of their information 2. Third Party Authorization: Besides conventional signing up, the APP also provides an alternative to sign in through a third party account such as google. 3. Location Based Weather: Upon logging in to the weather page, the system will automatically track the user's location and provide local weather information by default 4. Free Search Weather: The user can also enter any text in the search text box and an online API will perform fuzzy search and give back valid result 5. Account Setting: The user is allowed to set a default city to begin with instead of its local position. 6. Custom Styling: Users are also able to change the background color by their mood. 7. Account Deletion: If users decide to not use the APP anymore, the APP also offers a feature to delete all their informations stored in the database to ensure maximum privacy.

User Interfacing and Styling

Link to the video demo

Version Control Summary:

2 branches, 10 commit, 1 merge repo link

MVVM Integration

The login page is implemented using MVVM deisgn.

Software Design Patterns:

Four Patterns are used in the project, each one is explained with example of code provided.

1. Singleton Pattern This pattern ensures that a class has only one instance and provides a global point of access to it. In your project, the MongoDBHelper is effectively used as a singleton, though not explicitly implemented as one. example

public static DatabaseHelper Database { get; private set; }
public App(Auth0Client auth0Client, IMongoDatabase database)
{
    InitializeComponent();
    Database = new DatabaseHelper(database);
    _auth0Client = auth0Client;

    MainPage = new NavigationPage(new LoginPage(_auth0Client, Database));
}

2. Repository Pattern The MongoDBHelper class has the logic for accessing the MongoDB database, effectively acting as a repository. This pattern abstracts the data layer, making it easier to manage and test.

public class MongoDBHelper
{
    private readonly IMongoDatabase _database;

    public MongoDBHelper(IMongoDatabase database)
    {
        _database = database;
    }

    public IMongoCollection<UserRecord> GetUsersCollection()
    {
        return _database.GetCollection<UserRecord>("Users");
    }

    public async Task<int> SaveUserAsync(UserRecord user)
    {
        var collection = GetUsersCollection();
        await collection.InsertOneAsync(user);
        return 1;
    }

    public async Task<UserRecord> GetUserByEmailAsync(string email)
    {
        var collection = GetUsersCollection();
        var filter = Builders<UserRecord>.Filter.Eq("Email", email);
        var user = await collection.Find(filter).FirstOrDefaultAsync();
        return user;
    }

    public async Task UpdateUserAsync(UserRecord user)
    {
        var collection = GetUsersCollection();
        var filter = Builders<UserRecord>.Filter.Eq("Email", user.Email);
        var update = Builders<UserRecord>.Update
            .Set(u => u.Username, user.Username)
            .Set(u => u.DefaultCity, user.DefaultCity)
            .Set(u => u.BackgroundColor, user.BackgroundColor);
        await collection.UpdateOneAsync(filter, update);
    }

    public async Task DeleteUserAsync(string email)
    {
        var collection = GetUsersCollection();
        var filter = Builders<UserRecord>.Filter.Eq("Email", email);
        await collection.DeleteOneAsync(filter);
    }
}

3. Dependency Injection In the App class, Auth0Client and MongoDBHelper are injected into the constructors of other classes like LoginPage and WeatherPage

public App(Auth0Client auth0Client, IMongoDatabase database)
{
    InitializeComponent();
    Database = new DatabaseHelper(database);
    _auth0Client = auth0Client;

    MainPage = new NavigationPage(new LoginPage(_auth0Client, Database));
}

4. MVVM Like mentioned above, Model: Represents the data (e.g., UserRecord). View: Represents the UI (e.g., LoginPage.xaml).ViewModel: Contains the logic and data-binding

public partial class LoginPage : ContentPage
{
    public LoginPage(Auth0Client auth0Client, MongoDBHelper mongoDBHelper)
    {
        InitializeComponent();
        BindingContext = new LoginViewModel(auth0Client, mongoDBHelper);
    }
}

Seperation of Concerns

All code and files are organized in different folders based on its functionality and purpose.

Database Integration

The application integrates with the online MongoDB Atlas database, four CRUD opertions are included: Create: SaveUserAsync Read: GetUserByEmailAsync Update: UpdateUserAsync Delete: DeleteUserAsync

Cloud Integration

Three external online sources are used MongoDB : Online API to access the database 4 endpoints(Create/Read/Update/Delete) Auth0 : online third party authentication-authorisation 1 endpoint OpenWeather : online API to retrieve realtime weather information 1 endpoint