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
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 ( $ : @
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
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