GraphQL Sample

This is a small example project that uses the Apollo Kotlin GraphQL library on Android, with Github's API.

The aim is to explore this library and GraphQL in general.

Get a Github API Oauth token

👉 https://developer.github.com/v4/guides/forming-calls/#authenticating-with-graphql

Then put it in build.properties (follow the sample in build.properties.SAMPLE).

Get the GraphQL schema file

Either, manually: 👉 https://github.com/octokit/graphql-schema

Or using Apollo's gradle task:

./gradlew :app:downloadApolloSchema \
--endpoint='https://api.github.com/graphql' \
--schema='app/src/main/graphql/com/example/graphqlsample/queries/schema.graphqls'  \
--header="Authorization: Bearer <your token>"

(replace <your token> by the token you got from Github)

Architecture of the project

There is a single activity which is a host for 4 Compose layouts:

ViewerInfoLayout

Shows information about the "Viewer" (the currently logged-in user is called "Viewer" in the Github API):

• Login
• Name
• Email
• Total number of repos
• Info about the first 10 repos (name, description, number of stars)

Noteworthy:

• all this information is fetched with a single query (see ViewerInfoQuery.graphql)
• use of the @nonnull annotation (specific to the Apollo Kotlin library), to "improve" the schema

RepositoryListLayout

Displays a paginated list of the viewer's repositories.

Noteworthy:

• use of a GraphQL "fragment" (see UserRepositoryListQuery.graphql)
• how pagination works in GraphQL ("cursor")
• integration with the Android Pagination component

RepositorySearchLayout

Use the "search" operation and demonstrate a case with heterogeneous results - either User or Organization (see SearchQuery.graphql)

MiscLayout

Demonstrates mutations and error handling (see AddCommentToIssueMutation.graphql)

• Add comment to an issue that exists
• Add comment to an issue that doesn't exist (error case)

Useful links

• GraphQL spec
• Intro to GraphQL
• Apollo Kotlin README
• Medium article about Apollo Android coroutines extensions
• Github GraphQL API doc
• Github GraphQL Explorer (More info)
• GraphQL pagination

License

This is PUBLIC DOMAIN.