Weather App

Summary

A simple weather app that gets your location and displays the forecast for the current day and a few days after that.

API : OpenWeatherMap

Reason for choosing mentioned API :

• 1000 free api calls per day, good for a small project.
• Ability to specify different units in requests and receive a formatted response based on the unit i.e imperial/metric etc.
• Api response can also be modified to include the amount of needed data all with one call , contains icons for different conditions and has multilingual support if adopting for a wider audience is ever needed.
• They have a large user base and handle millions of requests, if the app were ever to scale, there's confidence on the api providing high availability.
• Has capabilities for alerts for severe weather conditions

More info on how to make an api call here.

Pre-requisite 📝

In your local.properties you will need to add your Open Weather API key and copy the urls in.

OPEN_WEATHER_API_KEY=YOUR KEY
OPEN_WEATHER_BASE_URL=https://api.openweathermap.org
OPEN_WEATHER_ICONS_URL=https://openweathermap.org/img/wn/

Check for one under Api Keys

Environment

• Built on A.S Hedgehog+
• JDK 17

Design/Architectural decisions 📐

The project makes use of common android patterns in modern android codebases.

Project Structure

The folders are split into 4 boundaries:

Core

Contains the models/data classes that are independent of any framework specific dependencies and represent the business logic. In a Clean Arch world you can consider these as your domain classes and interfaces.

Data

Contains data sources , local or remote, this is where the implementation for such is kept. All data related actions and formatting happens in this layer as well. It may contain framework related dependencies to orchestrate and create instances of data stores like a database or shared preference etc. One common pattern used in this area is the repository pattern, which mediates data sources and acts as a source of truth to the consumer.

DI

This acts as the glue between the core ,data and UI.The UI relies on the core models and interfaces which are implemented in data.

UI

Contains the presentation layer of the app, the screen components and viewmodels. Framework specific dependencies are best suited for this layer. In this layer MVI is also used, it looks similar to MVVM but the difference is the actions from a screen a.k.a intents e.g ```HomeScreenIntent``` are predefined and are finite,making the the screen state a bit more predictable and it's easier to scan through what actions are possible from a given screen.

The screen state e.g HomeScreenViewState is also modelled as a class with immutable properties and makes state management way easier by reducing the state whenever their is a new update received. Some design patterns that can be seen here are the Observer pattern when consuming the flow -> state flows in the composables and provides a reactive app.

Testing

The data layer is unit tested by mocking out external dependencies and the ui layer on the viewmodels, an integration test is written that makes use of fake,so as to mimic the real scenario as much as possible over using mocks, which would also turn it to a unit test.

Other Stuff 📦

Code style

For now there is no strict adherence to a code style, but the project is formatted using the default android studio formatter. You can run ./gradlew detekt to check for any code smells and ./gradlew ktlint to check for any linting issues. Alternatively for ktlint the IDE plugin might be a much better option :) Or setting up a pre-commit/pre-push hook to run the checks before a commit is made or pushed.

CI/CD

The project is built on Bitrise and the workflow is maintained from its dashboard.Github actions are responsible for dependency updates and running code quality checks ,defined in the .github/workflows folder.

Design System

Under the designsystem package ,it follows a tiered approach to styling the app i.e

Atoms (Smallest Components)

Typography: Define font styles, sizes, and weights for headers, paragraphs, and other text elements.

Color Palette: Establish a color palette with primary, secondary, and accent colors. Specify their usage in different contexts.

Icons: Design a set of basic icons that represent common actions or concepts. Ensure consistency in style and sizing.

Buttons: Create button styles with variations for primary, secondary, and tertiary actions. Include states like hover and disabled.

Input Fields: Design consistent styles for text inputs, checkboxes, radio buttons, and other form elements.

Molecules (Simple Components)

Form Elements: Combine atoms to create complete form components. Ensure consistency in spacing and alignment.

Cards: Combine text, images, and buttons to create card components. Define variations for different use cases.

Badges: Assemble icons and text to create badge components for notifications or status indicators.

Avatars: Design avatar components for user profiles, incorporating images or initials.

Organisms (Complex Components)

Navigation Bars: Create a consistent navigation bar design that includes menus, icons, and navigation elements.

Headers and Footers: Define headers and footers with appropriate spacing, logos, and navigation links.

Lists: Assemble atoms and molecules to create list components, incorporating variations like simple lists, detailed lists, and nested lists.

Modals: Design modal components for overlays or pop-ups, ensuring consistency in styles and behavior.

Templates (Page-Level Structures)

Page Layouts: Establish consistent layouts for different types of pages (e.g., home page, product page, settings page).

Grid Systems: Define grid systems that ensure alignment and consistency across various screen sizes.

Performance

The app is monitored using Firebase Performance and Crashlytics,for performance it's using the default traces but can be extended as the app grows to monitor specific parts of the app that might be slow. LeakCanary is also used to monitor for any memory leaks that might occur in debug mode.

Build Times

The current CI build time , factoring in the project size, the number of tests etc.

Task	Avg Time
Build - Bitrise	4m 30s
Code Analysis - Github Actions	6m 30s
Update Dependencies - Github Actions	8m 30s

Technologies 🔨

Language : Kotlin

Libraries :

UI

Compose
Coil
InAppUpdate

Data

Retrofit
OkHTTP
kotlinx.serialization
Preference Data Store

Testing

JUnit
Mockk
Truth
Turbine

Tooling/Project setup

Gradle secrets plugin
Hilt (DI)
Firebase - Crashlytics, Performance
Bitrise
Codecov
Detekt
Ktlint
LeakCanary
About Libraries
KMM

LICENSE

   Copyright 2023 David Odari

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
   

Screenshots 📱

Light Theme	Dark Theme
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