CODEWITHSUNDEEP
androidkotlinrepositorydata-layers
Tunahan
Tunahan

Reputation: 51

Android Data Layer RemoteDataSource Class and Repository

According to the article below. https://developer.android.com/jetpack/guide/data-layer#network-request

Make a network request Making a network request is one of the most common tasks an Android app might perform. The News app needs to present the user with the latest news that is fetched from the network. Therefore, the app needs a data source class to manage network operations: NewsRemoteDataSource. To expose the information to the rest of the app, a new repository that handles operations on news data is created: NewsRepository.

We need a data source class to manage network operations. It's a given example. As you can see API is a parameter of the NewsRemoteDataSource Class.

class NewsRemoteDataSource(
private val newsApi: NewsApi,
private val ioDispatcher: CoroutineDispatcher
) {
/**
 * Fetches the latest news from the network and returns the result.
 * This executes on an IO-optimized thread pool, the function is main-safe.
 */
suspend fun fetchLatestNews(): List<ArticleHeadline> =
    // Move the execution to an IO-optimized thread since the ApiService
    // doesn't support coroutines and makes synchronous requests.
    withContext(ioDispatcher) {
        newsApi.fetchLatestNews()
    }
}
}

// Makes news-related network synchronous requests.
interface NewsApi {
 fun fetchLatestNews(): List<ArticleHeadline>
}

However, I found lots of repositories like this. They're not using DataSource class. They're implementing API to the repository directly. According to the article above, android suggests the DataSource class to handle network operations. Which example is more effective? Which one should I use? What's the difference between them? Why lots of people are using 2nd one?

class CoinRepositoryImpl @Inject constructor(
    private val api: CoinPaprikaApi
    ) : CoinRepository {

    override suspend fun getCoins(): List<CoinDto> {
        return api.getCoins()
    }

    override suspend fun getCoinById(coinId: String): CoinDetailDto {
        return api.getCoinById(coinId)
    }
}

Upvotes: 5

Views: 1417

Answers (1)

Noamaw
Noamaw

Reputation: 123

I'll just mention one of the major building blocks of Development, which is also mentioned in the Object Oriented Programming. Polymorphism: "The ability to perform a certain action in different ways". With that said there is also the Principle of open-closed "Objects or entities should be open for extension but closed for modification"

As such, and with that in mind the 1st approach will be better as it allows you to add different DataSources to the Repository class. And you may also want to add on to it by turning the DataSource to an implementation of an interface. in that way the Repository class might currently be getting the NewsRemoteDataSource, but in a different tab it will receive the LiveScoresRemoteDataSource.

I hope this was helpful in answering your question.

Upvotes: 0

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