GraphQL with Kotlin

How to query and build a schema with GraphQL using Kotlin.

Transcript

1. GraphQL +Kotlin Mohit Sarveiya
2. — Query Language for your API developed at Facebook. — Polyglot implementation for client and server - Java, Javascript, Python, etc… — Reduces API requests needed and only gives you that data you asked for. What is GraphQL?
3. Problem — Too many API requests per month. — Would be good to get data for a 
 month in request.
4. GraphQL Overview query GetMonthData { campaign { date range posts { title created date } … } } Return Result Fetches Data Validates Client Server
5. GraphQL Overview query GetMonthData { campaigns { title posts { title } … } } Return Result Fetches Data Validates Query Result { campaigns { [ { title: “Campaign 1” posts: [ title: “Post 1” ] } … ] } }
6. DATABASE REST API CLIENTS GraphQL Server
7. DATABASE REST API GRAPHQL SERVER CLIENTS GraphQL Server
8. 1. How to query the sever 2. Build a GraphQL server in Kotlin
9. Star Wars Database Droids (R2D2, C3PO,…) — name, height, friends, 
 primary function.. Humans (Luke, Leia, Solo,…) — name, height, friends, planet…
10. Simple Query query Hero { hero { name } }
11. Simple Query query Hero { hero { name } } GraphQL Object defined in schema. Field on hero object.
12. Simple Query query Hero { hero { name } } { data: { hero: { name: “R2 -D2” } } } Query Result
13. 1. How to construct queries on Android in Kotlin
15. 1. Add Gradle Plugin. 2. Add schema definition to app in a JSON file. 3. Add queries to files with a “.graphql” file extension. 4. Use autogenerate classes from the “.graphql” files to make calls. Integrating Apollo Android Client
16. 1. Add Apollo Gradle Plugin
17. 2. Add Introspection of Schema (schema.json)
18. 3. Add Queries to file with “.graphql” ext File: queries.graphql
19. 4. Use ApolloClient object to make request
20. Arguments & Variables
21. Get Details for Droid with id - 2000.
22. Get Details for Droid for any id
23. Handling arguments on Android
24. Result Query
25. Enum Arguments
26. Supplying Enum Arguments on Android
27. Aliases & Fragments
28. Aliases
29. Aliases
30. Aliases
31. Aliases
32. Fragments
33. Fragments
34. Fragments
35. Mutations
36. Create a Review for an Episode
37. Mutating on Android
38. Mutation Result
39. 2. Building a GraphQL server
42. — GraphQL Object type — Scalar types (String, Int, Float, Boolean) — List type — Interface type — Enum type — Union type — Input Object type GraphQL Type System
43. Star Wars Database Droids (R2D2, C3PO,…) — name, height, friends, 
 primary function.. Humans (Luke, Leia, Solo,…) — name, height, friends, planet…
44. — Common fields between Human and Droid — name — height — friends — appearsIn Create an interface
45. Character Interface
46. Droid GraphQL Object
47. Human GraphQL Object
48. Enum Types
49. Schema Structure
50. Query Type
51. Parsing Queries and Returning Results
53. — Client and server Java GraphQL implementations are not stable. — No Kotlin only GraphQL implementation. — Learning curve. — Need to setup GraphQL server on top of your infrastructure. This requires more work. Disadvantages
54. Thanks! May the force be with you! Twitter: @heyitsmohit Github: http://github.com/mysa