DartPollo

Build Dart types from GraphQL schemas and queries using Introspection Query.

Overview

DartPollo is a code generator that builds Dart types from GraphQL schemas and queries. It helps you integrate GraphQL into your Dart and Flutter applications by generating type-safe models from your GraphQL operations.

Features

• Generate Dart classes from GraphQL schemas and queries
• Support for GraphQL fragments
• Support for GraphQL mutations and subscriptions
• Custom scalar mapping
• Integration with json_serializable for JSON serialization
• Type-safe GraphQL operations

Installation

Add DartPollo to your pubspec.yaml:

dependencies:
  dartpollo: ^0.0.1

dev_dependencies:
  build_runner: ^2.4.15

Usage

Basic Setup

1. Create a build.yaml file in your project root:

targets:
  $default:
    builders:
      dartpollo:
        options:
          schema_mapping:
            - schema: your_schema.graphql
              queries_glob: lib/graphql/**.graphql
              output: lib/graphql/generated/

2. Create your GraphQL schema file (or use introspection to generate it)

3. Write your GraphQL queries in .graphql files:

Example GraphQL query file (lib/graphql/get_user.graphql):

# Replace this with your actual GraphQL query based on your schema
query GetUser($id: ID!) {
  # Fields will depend on your specific GraphQL schema
}

4. Run the build_runner to generate Dart code:

dart run build_runner build

5. Use the generated code in your application:

import 'package:your_package/graphql/generated/get_user.graphql.dart';

void main() {
  final query = GetUserQuery(variables: GetUserArguments(id: '123'));
  // Use the query with your GraphQL client
}

Configuration Options

DartPollo can be configured with various options in your build.yaml file:

targets:
  $default:
    builders:
      dartpollo:
        options:
          schema_mapping:
            - schema: your_schema.graphql
              queries_glob: lib/graphql/**.graphql
              output: lib/graphql/generated/
          scalar_mapping:
            - graphql_type: Date
              dart_type: DateTime
          custom_parser_import: 'package:your_package/graphql/parsers.dart'
          fragments_glob: 'lib/graphql/fragments/**.graphql'
          naming_scheme: pathedWithTypes # or simple

Examples

Check the example directory for complete examples of using DartPollo with different GraphQL servers.

Custom Scalars

You can map GraphQL scalar types to Dart types using the scalar_mapping configuration:

scalar_mapping:
  - graphql_type: Date
    dart_type: DateTime
    use_custom_parser: true
  - graphql_type: JSON
    dart_type: Map<String, dynamic>

If use_custom_parser is set to true, you need to provide custom parsing functions in a separate file and reference it with custom_parser_import.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.