GraphQL in Android Like a Pro: Efficient Data Fetching with Apollo

Tired of over-fetching data with REST APIs? Let’s talk GraphQL—the query language that lets your Android app ask for exactly what it needs. Paired with Apollo Client, you’ll fetch data faster, reduce boilerplate, and build scalable apps. Here’s how to implement it like a pro.

Why GraphQL?

• No Over-Fetching: Request only the fields you need.
• Strong Typing: Catch errors at compile time.
• Single Endpoint: Simplify API management.

Step 1: Add Apollo Client to Your Project

Add these dependencies to your build.gradle:

// Project-level build.gradle  
plugins {  
    id("com.apollographql.apollo3").version("3.8.3") apply(false)  
}  

// App-level build.gradle  
plugins {  
    id("com.apollographql.apollo3")  
}  

dependencies {  
    implementation("com.apollographql.apollo3:apollo-runtime:3.8.3")  
    implementation("com.squareup.okhttp3:okhttp:4.12.0") // For HTTP calls  
}  

Step 2: Define Your GraphQL Query

Create a .graphql file under src/main/graphql/com/yourpackage:

# GetUser.graphql  
query GetUser($id: ID!) {  
    user(id: $id) {  
        id  
        name  
        email  
        posts {  # Nested query  
            title  
            likes  
        }  
    }  
}  

Sync your project—Apollo auto-generates Kotlin models!

Step 3: Initialize Apollo Client

// Create a singleton ApolloClient  
object GraphQLClient {  
    private const val BASE_URL = "https://api.yourgraphql.com/"  

    val instance: ApolloClient by lazy {  
        ApolloClient.Builder()  
            .serverUrl(BASE_URL)  
            .okHttpClient(OkHttpClient.Builder().build())  
            .build()  
    }  
}  

Step 4: Execute the Query

Fetch data in a ViewModel using coroutines:

class UserViewModel : ViewModel() {  
    private val apolloClient = GraphQLClient.instance  

    fun fetchUser(userId: String) = viewModelScope.launch {  
        try {  
            val response = apolloClient.query(GetUserQuery(id = userId)).execute()  
            if (!response.hasErrors()) {  
                val user = response.data?.user  
                // Update UI with user.name, user.posts, etc.  
            } else {  
                // Handle GraphQL errors  
            }  
        } catch (e: Exception) {  
            // Handle network errors  
        }  
    }  
}  

Pro Tips for GraphQL Ninjas

1. Use Fragments: Reuse common fields across queries.

fragment UserDetails on User {  
    id  
    name  
}  

1. Paginate Smartly: Leverage cursor-based pagination.
2. Cache Strategically: Apollo caches responses automatically—customize with ApolloStore.

Common Pitfalls

• Schema Mismatches: Always sync your .graphql files after API changes.
• Over-Nesting: Deep queries can slow down responses.
• Ignoring Coroutines: Never block the main thread!

GraphQL vs. REST?

• GraphQL Wins: When you need flexibility, multiple data sources, or optimized payloads.
• REST Wins: For simple, cacheable endpoints.

Your Turn:
Replace one REST call in your app with GraphQL this week.
Comment below: What’s your biggest GraphQL struggle?

#AndroidDev #GraphQL #Apollo #Kotlin #MobileApps