GraphQL-ify your API - JFall 2022
- 2. SOHAM DASGUPTA Father and Football lover Tech Enthusiast/Programmer/Architect Speaker & Blogger Twitter : @iamsoham LinkedIn: dasguptasoham Github: sohamda Medium: @iam.soham
- 3. What’s in store today GraphQL What Queries & Mutation Schemas & Types Show me some code graphql-java graphql-java-kickstart graphql-dgs-framework spring-graphql What’s better Implementation easiness – code, generation, error handling, testing, clients N+1 problem
- 4. Let me tell you story... Provider names and associated Services Provider (names) Services Services with associated Provider Valid Services Services + Provider + logged in User region Providers + Services + logged in User region Providers + Services + No email addr for unauthorized
- 5. GraphQL is a query language for your API, and a server-side runtime for executing queries. Backed by your existing code and data. It was designed by Facebook to get around common constraints in fetching data via REST. Nothing to do with Graph DB. Not a replacement of REST. Not going to magically solve every API design issues. What’s GraphQL
- 6. Schema Query Results Schema , Query & Results GraphQL provides description of the data in your API, gives clients the power to ask for exactly what they need.
- 8. Hierarchical & Aggregator Strongly Typed Validation & Type check out-of-the-box API evolution without versioning GraphQL Characteristics
- 9. Query & Mutation • Ask what you need. • Expand the same query. • Send arguments. • Use Aliases, Fragment Schemas & Types • GraphQL schema language - allows us to talk about GraphQL schemas in a language-agnostic way. • Scalar : Int, String, Boolean, ID, Float • Lists & Non-Null • Union, Interfaces, Input Types
- 10. N+1 queries Caching complexity Community presence Pagination GraphQL Maturity
- 11. Show me some code graphql-java graphql-java-kickstart graphql-dgs-framework spring-graphql
- 13. graphql-java https://www.graphql-java.com/documentation/getting-started https://github.com/graphql-java - Version 18.2 : Last updated on June’22 https://github.com/graphql-java/graphql-java-spring This project is archived in favor of the official Spring GraphQL integration
- 15. graphql-java- kickstart https://graphql-java-kickstart.com/ https://github.com/graphql-java-kickstart Version 14 : Last updated on Aug’22
- 17. dgs-framework https://netflix.github.io/dgs/ https://github.com/Netflix/dgs-framework Version 5.4.1 : Last updated on Oct’22
- 19. Spring GraphQL https://docs.spring.io/spring- graphql/docs/current/reference/html/ https://github.com/spring-projects/spring-graphql Version 1.0.2 : Last updated on Sep’22
- 21. What’s better Implementation easiness – code, generation, error handling, testing, clients N+1 problem
- 22. 22 DataFetchers Piece of code that fetches the data 1. Define a @Component which defines datafetching methods. 2. Register them in while building/parsing the schema graphql-java
- 23. 23 DataFetchers Piece of code that fetches the data 1. Define @Component which implements GraphQLQueryResolver. 2. For field-level define a @Component which implements GraphQLResolver<T>. graphql-java-kickstart
- 24. 24 DataFetchers Piece of code that fetches the data 1. Define a @DgsComponent. 2. Map the schema operations with @DgsData dgs
- 25. 25 DataFetchers Piece of code that fetches the data 1. Define a @Controller. 2. Map the schema operations with @SchemaMapping or @QueryMapping spring-graphql
- 26. What’s N+1 when the data access framework executed N additional SQL statements to fetch the same data that could have been retrieved when executing the primary SQL query
- 27. 27 DataLoaders Piece of code that is responsible for N+1 query issue 1. Define a BatchLoader which return s a CompletableFuture. 2. Define a DataLoaderRegistry @Bean which registers the Loader. 3. Define a DataFetcher using that Loader. graphql-java
- 28. 28 DataLoaders Piece of code that is responsible for N+1 query issue 1. Define @Component which defines a loader and adds it to the registry. 2. Define a @Component which implements GraphQLServletContextBuilder and associate the registry. 3. Define a @Component which invokes the dataloader. graphql-java-kickstart
- 29. 29 DataLoaders Piece of code that is responsible for N+1 query issue 1. Define a @DgsDataLoader. 2. Map the schema operations with @DgsData dgs
- 30. 30 DataLoaders Piece of code that is responsible for N+1 query issue 1. Register (Mapped)BatchLoader. 2. Map it to the method that can be invoked for a list of keys. 3. Load the dataloader with @SchemaMapping/@QueryMapping spring-graphql
- 31. 31 Error Handling Piece of code that handles exceptions/errors 1. Implement GraphQLError graphql-java
- 32. 32 Error Handling Piece of code that handles exceptions/errors • Enable ExceptionHandler property and handle them in a Spring way. OR • Implement GraphQLErrorHandler and manage the errors in overridden method. graphql-java-kickstart
- 33. 33 Error Handling Piece of code that handles exceptions/errors • Define a @Component which implements DataFetcherExceptionHandler dgs
- 34. 34 Error Handling Piece of code that handles exceptions/errors 1. Define a Config bean and register the exception handlers. spring-graphql
- 35. 35 Client How to call a GraphQL API 1. No defined way. 2. Needs text templates to generate requests. graphql-java
- 36. 36 Client How to call a GraphQL API 1. Gives a Webclient library. 2. Needs text templates to generate requests. graphql-java-kickstart
- 37. 37 Client How to call a GraphQL API 1. GraphQLClient uses String as query which is same as the previous two. 2. Code generation using Gradle/Maven. This is the type-safe option. dgs
- 38. 38 Client How to call a GraphQL API 1. Define WebGraphQlClient object. 2. Options are http, websocket, rsocket. 3. Executing the query gives Mono object. 4. Responses can be mapped to an custom object. spring-graphql
- 39. Testing & Code Generation grpahql-java graphql-java-kickstart dgs spring-graphql X X 1. Code generation using Gradle/Maven. This is the type-safe option. 2. Use the generated classes to build request and test using DgsAutoConfiguration class. 1. No Code generation. 2. @AutoConfigureGraphQlT ester to initialize context. 3. Responses can be mapped to custom objects.
- 40. graphql-java graphql-java- kickstart dgs spring-graphql • Is there since long, so evolved and matured. • A lot of Boilerplate code just to write a simple API. • Library for Spring boot is archieved. • Not a easy way to Unit Test everything you write. • No Clients avaiable. Need to use text templates to create queries. • Matured but missing extended documentation. • Still a bit of Boilerplate code. • Directly usable within Springboot. Although other modules available to work on Java only environments. • Not a easy way to UT everything you write. • Basic Client avaiable. • Not sure about maturity, but Netflix is behind this, so faith is there. • Dataloader needs list of keys. • No Boilerplate code. • Directly usable within Springboot. • You can UT everything you write. • Client avaiable. • Code generation using Gradle/Maven. • Just released not enough usage data available. • No Boilerplate code. • Spring is behind this. • You can UT everything you write. • Client avaiable. • No Code generation. Final words
- 41. Soham Dasgupta • Twitter : @iamsoham • LinkedIn: dasguptasoham • Github: sohamda • Medium: @iam.soham Slides: https://bit.ly/3B02NSZ Code : https://bit.ly/3ofzep2