Get started with Kotlin
Add the Gradle plugin
In your app Gradle file, apply the com.apollographql.apollo
plugin:
Using the plugins DSL:
plugins {
// ...
id("com.apollographql.apollo").version("x.y.z")
}
Or using the legacy syntax:
buildscript {
// ...
classpath("com.apollographql.apollo:apollo-gradle-plugin:x.y.z")
}
apply(plugin = "com.apollographql.apollo")
The plugin is hosted on the Gradle plugin portal, Jcenter and Maven Central.
Configure the plugin
apollo {
// instruct the compiler to generate Kotlin models
generateKotlinModels.set(true)
}
Add the runtime dependencies
dependencies {
// The core runtime dependencies
implementation("com.apollographql.apollo:apollo-runtime:x.y.z")
// Coroutines extensions for easier asynchronicity handling
implementation("com.apollographql.apollo:apollo-coroutines-support:x.y.z")
}
Download your schema.json
file
Apollo Android requires your GraphQL server's schema as a schema.json
file. You can obtain the contents of this file by running an introspection query on your server.
Note: If you don't have a GraphQL server yet, you can use the server from the tutorial: https://apollo-fullstack-tutorial.herokuapp.com/graphql.
The Apollo Gradle plugin exposes a downloadApolloSchema
task to help you obtain your schema. Provide this task your server's GraphQL endpoint and the output location for the schema.json
file:
./gradlew downloadApolloSchema \
--endpoint="https://your.domain/graphql/endpoint" \
--schema="src/main/graphql/com/example/schema.json"
If your GraphQL endpoint requires authentication, you can pass custom HTTP headers:
./gradlew downloadApolloSchema \
--endpoint="https://your.domain/graphql/endpoint" \
--schema="app/src/main/graphql/com/example" \
--header="Authorization: Bearer $TOKEN"
Add your query
- Create a directory for your GraphQL files:
src/main/graphql/com/example/
- Add your
schema.json
to the directory:src/main/graphql/com/example/schema.json
- Put your query in a
.graphql
file, next to the schema:src/main/graphql/com/example/LaunchDetails.graphql
query LaunchDetails($id:ID!) {
launch(id: $id) {
id
site
mission {
name
missionPatch(size:LARGE)
}
}
}
- Build your project, this will generate the model
Execute your query
You use an instance of the ApolloClient
class to interact with your server and cache.
To make a query using your generated models:
// First, create an `ApolloClient`
// Replace the serverUrl with your GraphQL endpoint
val apolloClient = ApolloClient.builder()
.serverUrl("https://your.domain/graphql/endpoint")
.build()
// in your coroutine scope, call `ApolloClient.query(...).toDeferred().await()`
scope.launch {
val response = try {
apolloClient.query(LaunchDetailsQuery(id = "83")).toDeferred().await()
} catch (e: ApolloException) {
// handle protocol errors
return@launch
}
val launch = response.data?.launch
if (launch == null || response.hasErrors()) {
// handle application errors
return@launch
}
// launch now contains a typesafe model of your data
println("Launch site: ${launch.site}")
}
What's next
- Execute your first mutation
- Handle custom scalar types
- Factor common patterns using fragments