coco
141 lines
5.1 KiB
Markdown
141 lines
5.1 KiB
Markdown
# CoinCap - (I'm not maintaining this project anymore)
|
|
|
|
Best practice (Modularization) - built entirely with Jetpack Compose and cutting-edge libraries like
|
|
Coroutines, Flow, Hilt, Coil, etc.
|
|
|
|
This project is using Material 3 components, as well as the Compose navigation library. It also has
|
|
an integrated Static Analysis tool (Detekt) and CI/CD pipeline (Github Actions) + web scraping using a python script.
|
|
|
|
### Libraries and Tools
|
|
|
|
- Jetpack Compose
|
|
- Hilt
|
|
- Retrofit (with a deserializer for another API)
|
|
- Coroutines
|
|
- Coil
|
|
- Detekt
|
|
- GitHub Actions
|
|
- Material 3
|
|
- Compose Navigation
|
|
|
|
#### CI/CD
|
|
|
|
- I've used GitHub Actions, and Bitrise just to see different results from different platforms, and
|
|
so far, IMO, GitHub Actions is nicer, Bitrise already has everything but I'd like to have some
|
|
flexibility and write some scripts :)
|
|
|
|
- There was an issue with the previous local rates API, from bonbast.com which I replaced that with
|
|
a new strategy. I've used a new script to scrap the data with Github Actions and store it in a
|
|
file called currencies.json. The script is available in the project.
|
|
|
|
### Showcase
|
|
|
|
https://user-images.githubusercontent.com/15968667/210910446-79249585-3c54-451f-a310-b32088a35313.mp4
|
|
|
|
<p>
|
|
<img src="https://i.imgur.com/4hQXpR2.png" height="420" />
|
|
<img src="https://i.imgur.com/kZJbtow.png" height="420" />
|
|
<img src="https://i.imgur.com/5cGryi7.png" height="420" />
|
|
<img src="https://i.imgur.com/wMx9kOL.png" height="420" />
|
|
</p>
|
|
|
|
### Architecture
|
|
|
|
I've used the best practices from Google's official
|
|
repository [NowInAndroid](https://github.com/android/nowinandroid), and used Modularization to make
|
|
the app more scalable and maintainable.
|
|
|
|
### Modules
|
|
|
|
<img src="https://i.imgur.com/21DcyNY.png" width="400">
|
|
|
|
### Features
|
|
|
|
1. The logic behind searching is to get the data only after the last character is entered (using
|
|
`flatMapLatest()` flow operator).
|
|
2. For the home screen, I am planning to get some data from the server for showing on the LineChart,
|
|
but for now, I am using dummy data.
|
|
3. Unfortunately, the API doesn't provide the data for the `LineChart`, so I am using dummy data for
|
|
now.
|
|
4. Iran (my home country) has been facing inflation for the last decade, and surprisingly, because
|
|
of protests and the lack of management, the inflation rate is increasing day by day. So, I took
|
|
the chance and put a logic for showing the rates in different currencies as **Local Currency**,
|
|
with a refresh policy between Saturday to Thursday, and the rates will be updated every 5
|
|
minutes. For Friday, the rates will be retrieved from the previous day.
|
|
|
|
### Implementation
|
|
|
|
This section is for those who are interested in the implementation details.
|
|
|
|
#### Home Screen
|
|
|
|
I had to combine two flows into one to avoid unnecessary network calls and extra logics inside
|
|
views. So here is how I did it:
|
|
|
|
<img src="https://i.imgur.com/c4rrVzx.jpg" width="520">
|
|
|
|
The implementation is pretty simple. I am using the `combine` operator to combine the two flows into
|
|
one. The `combine` operator will emit a new [Rate] model after multiplying the two values. The logic
|
|
and code is available in
|
|
the [GetRatesUseCaseImpl](https://github.com/LinX64/CoinCap/blob/master/core/data/src/main/java/com/client/data/repository/foreignRates/RatesRepositoryImpl.kt)
|
|
class.
|
|
|
|
#### API calls and deserialization
|
|
|
|
I am using Retrofit for making API calls, and I am using a custom deserializer for the local
|
|
currency API. The problem that I faced at first was that the original API was not free so I had to
|
|
use an already made API instead. Another problem was that the API was returning the data in a
|
|
different format, something like this format:
|
|
|
|
````
|
|
{
|
|
"usd": {
|
|
"sell": 43000,
|
|
"buy": 42900
|
|
},
|
|
"eur": {
|
|
"sell": 45870,
|
|
"buy": 45720
|
|
}
|
|
}
|
|
````
|
|
|
|
It was pretty hard to deserialize the data, so I had to write a custom deserializer for it. The
|
|
deserializer is basically converting all those three objects into a list of [LocalRate] objects.
|
|
Here you can find the
|
|
deserializer: [CurrencyDeserializer](https://github.com/LinX64/CoinCap/blob/master/core/data/src/main/java/com/client/data/util/CurrencyDeserializer.kt)
|
|
|
|
I am sure this is one of the major problems that all Android developers might face while
|
|
using `GSON` and `Retrofit`, so I hope this will help you.
|
|
|
|
### API
|
|
|
|
For this project, I am
|
|
using [CoinCap API](https://docs.coincap.io/#ee30bea9-bb6b-469d-958a-d3e35d442d7a) for rates, as
|
|
well as
|
|
[This API](https://bonbast-api.deta.dev/) for live Iranian exchange rates.
|
|
|
|
Also, I am using https://coinicons-api.vercel.app/api/icon/ for getting the icons of the coins.
|
|
|
|
### Continuous Integration
|
|
|
|
The project is using GitHub Actions to build and test the app on every push and pull request on two
|
|
devices. Also, it is using Renovate to keep the dependencies up to date.
|
|
|
|
### Static Code Analysis
|
|
|
|
The project is using Detekt for static code analysis, and it is using GitHub Actions to run the
|
|
analysis on every push and pull request.
|
|
|
|
I also used Detekt formatter to format the code automatically which is somehow a wrapper for ktLint
|
|
as well.
|
|
|
|
Please see: https://detekt.dev/docs/rules/formatting
|
|
|
|
### TODO
|
|
|
|
- Add Offline first support
|
|
- Unit Tests
|
|
- Get data from Server for LineChart
|
|
- Add more features
|