Apollo_Code_Generation [en]

Transcript

1. Apollo Code Generation

2. Introduction Yuya Horita iOS Engineer @CyberAgent, 2017/4 ~ 2019/5 Software

   Engineer @M3, 2019/5 ~ GitHub: https://github.com/horita-yuya Twitter: https://twitter.com/horita_yuya Medium: https://medium.com/@yuyaHorita
3. None

4. schema.json *.graphql ʴ

5. schema.json File contains the results of an introspection query, or

   query information > Conventionally this file is called schema.json Reference: https://www.apollographql.com/docs/ios/downloading-schema/

6. *.graphql Query definition file

7. schema.json *.graphql ʴ

8. schema.json *.graphql Token AST IR →

9. Lexer .graphql to Tokens

10. User.graphql

11. User.graphql Tokens query User ( $ id email @ include

    … AddressFragment Debug : response ~~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~~

12. query User ( $ @ … AddressFragment NAME Kind Value

    undefined undefined undefined undefined COMMENT Debug Ignoring on parsing phase name : undefined

13. `#` itself is not a token kind. -> Other ways

    to comment out, like `/**/`?

14. https://github.com/graphql/graphql-js/blob/master/src/language/lexer.js#L187 https://github.com/graphql/graphql-spec/issues/276 Reading implementation of lexer, it seems only `#`

    indicates comment.

15. Parser Tokens to AST

16. query User AddressFragment NAME NAME NAME Operation definition name NAME

    Tokens Semantics Operation name field name Fragment name

17. ( $ @ … Beginning of definition of arguments, etc.

    Variable Directive Fragment/Inline Fragment Spread Tokens : Argument, Alias, etc. Semantics

18. NAME Token: Semantics depends on syntax and value. Punctuator Token:

    Semantics is fixed or depends on syntax ( $ : @
19. None

20. Document Hoge parsing operation function parseHoge is defined in graphql/language/parser.js

    = OperationDefinition OperationType Name VariableDefinitions VariableDefinition SelectionSet VariableDefinition Recursive Descent Parsing

21. Tokens Rules + Starts with operation definition keyword `query`. The

    next `User` is operation name. If `(` exists in just after `User`, variable definitions starts. It will end with `)`. Next `{` means the beginning of definition of SelectionSet ……

22. VariableDefinitions Document OperationDefinition FragmentDefinition AST OperationType VariableDefinition VariableDefinition

23. IR Generator AST to IR

24. None
25. None
26. None

27. VariableDefinition Type Variable Name value: string Name value: string

28. Type Variable Name value: id Name value: Int! VariableDefinitions VariableDefinition

    VariableDefinition Type Variable Name value: withEmail Name value: Boolean!

29. VariableDefinitions VariableDefinition VariableDefinition + schema.json GraphQLType GraphQLType Type Variable Name

    value: id Name value: Int! Type Variable Name value: withEmail Name value: Boolean!

30. IR

31. IR CompilerContext LegacyCompilerContext

32. Summary 1. AST from *.graphql. 2. IR from ast and

    schema.json. 3. .swift, .ts, .scala from IR 4. It seems .kt doesn’t use apollo-tooling. All implementations are in apollo-android.

33. Appendix

34. Lexer Lexer: https://github.com/graphql/graphql-js/blob/master/src/language/lexer.js Token Kind: https://github.com/graphql/graphql-js/blob/master/src/language/tokenKind.js

35. Parser Parser: https://github.com/graphql/graphql-js/blob/master/src/language/parser.js
 AST: https://github.com/graphql/graphql-js/blob/master/src/language/ast.js AST Kind: https://github.com/graphql/graphql-js/blob/master/src/language/kinds.js

36. IR Compiler: https://github.com/apollographql/apollo-tooling/blob/master/packages/apollo-codegen- core/src/compiler/index.ts