brick_offline_first_with_rest_build workflow

Brick Offline First with Rest Build

Code generator that provides (de)serializing functions for Brick adapters using RestProvider and SqliteProvider within the OfflineFirstWithRest domain. Classes annotated with ConnectOfflineFirstWithRest and extending the model OfflineFirstWithRest will be discovered.

Setup

dart:mirrors will conflict with Flutter, so this package should be imported as a dev dependency and executed before an app's run time.

dev_dependencies:
  brick_offline_first_with_rest_build:
    git:
      url: git@github.com:greenbits/brick.get
      path: packages/brick_offline_first_with_rest_build

Build your code:

cd my_app; (flutter) pub run build_runner build

How does this work?

OfflineFirst Builder

  1. A class is discovered with the @ConnectOfflineFirstWithRest annotation.
       @ConnectOfflineFirstWithRest(
         sqliteConfig: SqliteSerializable(
           nullable: false
         ),
         restConfig: RestSerializable(
           endpoint: "=> '/my/endpoint/to/models';"
         )
       )
       class MyClass extends OfflineFirstModel
    
  2. OfflineFirstGenerator expands respective sub configuration from the @ConnectOfflineFirstWithRest configuration.
  3. Instances of RestFields and SqliteFields are created and passed to their respective generators. This will expand all fields of the class into consumable code. Namely, the #sorted method ensures there are no duplicates and the fields are passed in the order they're declared in the class.
  4. RestSerialize, RestDeserialize, SqliteSerialize, and SqliteDeserialize generators are created from the previous configurations and the aforementioned fields. Since these generators inherit from the same base class, this documentation will continue with RestSerialize as the primary example.
  5. The fields are iterated through RestSerialize#coderForField to generate the transforming code. This function produces output by checking the field's type. For example, final List<Future<int>> futureNumbers may produce 'future_numbers': await Future.wait<int>(futureNumbers).
  6. The output is gathered via RestSerialize#generate and wrapped in a function such as MODELToRest(). All such functions from all generators are included in the output of the adapter generator. As some down-stream providers or repositories may require extra information in the adapter (such as restEndpoint or tableName), this data is also passed through #generate.
  7. Now with the complete adapter code, the AdapterBuilder saves adapters/MODELNAME.g.dart.
  8. Now with all annotated classes having adapter counterparts, a model dictionary is generated and saved to brick.g.dart with the ModelDictionaryBuilder.
  9. Concurrently, the super generator may produce a new schema that reflects the new data structure. SqliteSchemaGenerator generates a new schema. Using SchemaDifference, a new migration is created (this will be saved to db/migrations/VERSION_migration.dart). The new migration is logged and prepended to the generated code. This will be saved to db/schema.g.dart with the SqliteSchemaBuilder. A new migration will be saved to db/<INCREMENT_VERSION>.g.dart with the NewMigrationBuilder.

FAQ

Why doesn't this library use JsonSerializable?

While JsonSerializable is an incredibly robust library, it is, in short, opinionated. Just like this library is opinionated. This prevents incorporation in a number of ways:

  • @JsonSerializable detects serializable models via a class method check. Since @ConnectOfflineFirstWithRest uses an abstracted builder, checking the source class is not effective.
  • @JsonSerializable only supports enums as strings, not as indexes. While this is admittedly more resilient, it can’t be retrofitted to enums passed as integers from an API.
  • Lastly, dynamically applying a configuration is an uphill battle with ConstantReader (the annotation would have to be converted into a digestable format). While ultimately this could be possible, the library is still unusable because of the aforementioned points.

JsonSerializable is an incredibly robust library and should be used for all other scenarios.

Libraries

builder