graphql-to-dart

Custom templates for graphql-code-generator for generating dart PODOs and json_serializable classes

2.0.0 Beta

This beta makes the api entirely immutable

npm install [email protected] includes a number of updates, such as:

• per-operation file generation (probably non-optional)
• gql_code_gen support via integrateGqlCodeGenAst
• transformCharacters support for handling _underscore_prefixed fields defaults to { "^_+": "" }, resulting in "__typename" -> "typename"
• Models graphql-style "inheritance" by defining a protected _$[Type}Fields type along with every object type, which is then exposed by fragment mixins and selection sets.
• Fragments are modeled generated as mixins, as well as standalone FragmentNameSelectionSet classes
• all classes are immutable and use the equatable package

usage

yarn add -D graphql-code-generator graphql [email protected]

write codegen.yaml to customize your build as needed. This is the full working config I'm using in the wild:

schema: schema/__generated__/schema.json
documents:
  # fragments are _private and collected first
  # so we can hack their fields
  - '../app/lib/**/_*.graphql'
  - '../app/lib/**/!(_)*.graphql'
overwrite: true
generates:
  ../app/lib/graphql/schema.dart:
    - graphql-to-dart/schema-types
  ../app/lib/:
    # generate operation types next to their source files
    # NOTE there's actually a coupling between the preset and plugin
    # with respect to `integrateGqlCodeGenAst` atm
    preset: graphql-to-dart
    presetConfig:
      # all required
      extension: .graphql.dart
      packageName: savvy_app
      schemaTypesPath: ../app/lib/graphql/schema.dart
    plugins:
      - graphql-to-dart/documents
config:
  # re-export built gql_code_gen ast files
  integrateGqlCodeGenAst: true
  schema:
    imports:
      # import 'package:foo/bar.dart' show biz; works as well here
      - package:savvy_app/graphql/scalars/scalars.dart
      - package:savvy_app/graphql/base.dart
    exports:
      - package:savvy_app/graphql/scalars/scalars.dart
      - package:savvy_app/graphql/base.dart
  mixins:
    # add `with Entity` when a generated class has these fields
    - when:
        fields:
        - entityId
        - validFrom
        - validUntil
      name: Entity
  scalars:
    Date: DateTime
    # requires a PGDateTimeProvider in the schema lib
    Datetime: PGDateTime
    FiniteDatetime: DateTime
    UUID: String
    Rrule: RecurrenceRule
    Cursor: String
    JSON: Object
  replaceTypes:
    TemporalIdInput: TemporalId
    # Replace with a reference, if I remember correctly
    TemporalId: TemporalId
    GoogleSignInInput: GoogleSignIn
  irreducibleTypes:
   # I have a common in-fragment type
   # that is always inherited the same way,
   # so I just repace it's inputs and make my own irreducible.
   - TemporalId

Then generate with yarn gql-gen (or gql-gen if you have it globally installed), And theeeen generate the actual json serializers (equatable and json_serializable are peer dependencies, but on the flutter side, also gql_code_gen if you're using the ast integration). So:

yarn gql-gen
flutter packages pub run build_runner build
flutter format lib/**/*graphql.dart # you're gunna want this
# or npm install globstar && globstar -- flutter format "lib/**/*.graphql.dart"

Make sure you have a build.yaml like in the example, and the deps in the pubspec.yaml:

# ...
dev_dependencies:
  build_runner: ^0.9.0
  json_serializable: ^0.5.4
  # ...

dependencies:
  json_annotation: ^0.2.3
  equatable: 1.0.2
  # ...
# ...

...Obviously this is not the most user friendly process yet.

Take a look at the example output to see how it generates code, as well as src/build-plugin.ts for the configuration object, which has some docs just aching to be properly generated.

• (almost) all types have
  • isValid, validate helpers
  • mergedLeftWith(ThisType other) and mergedRightWith(ThisType other) helpers, aliased to the << and >> operators respectively
• selection sets have copyWith helpers and a .partial constructor
• For some reason I can't override copyWith properly - maybe because of covariant semantics idk.

NOTES

• Base types do not currently have json helpers, but it should probably be configurable in case of the configuration replaceTypes: { "BaseTypeInput": "BaseType" }
• I probably won't touch this for a while once again.
• Really what we want is for @klavs's gql_code_gen to become more mature, but I keep sinking energy into this because I can go fast here
• #import "./fragment.graphql bolton support has been merged into gql_code_gen
• (possibly outdated): You can have multiple inline fragments on the same document, but they will be named with leading underscores, like Query_TypeInlineFragment, which is ugly