feat: Custom Json Serializable Parser for Specific Field Types

swagger_parser/CHANGELOG.md

@@ -1,3 +1,6 @@
+## 1.41.0
+- Add `field_parsers` option for setting field parsers for JSON serializable
+
 ## 1.40.0
 - Add `include_paths` option for filtering endpoints by paths
 

swagger_parser/README.md

@@ -169,6 +169,22 @@ swagger_parser:
     - "/some/wildcard/*/path"
     - "/another/wildcard/**"
 
+  # Optional (dart & json_serializable only). Set field parsers for JSON serializable.
+  #
+  # Field parsers are used to parse specific fields of a DTO.
+  #
+  # Parser must implements JsonConverter<T, Object?> interface from json_annotation package.
+  field_parsers:
+    - apply_to_type: "int"
+      parser_name: "CustomIntParser"
+      parser_absolute_path: "package:your_package/lib/utils/parsers/custom_int_parser.dart"
+    - apply_to_type: "int?"
+      parser_name: "CustomNullableIntParser"
+      parser_absolute_path: "package:your_package/lib/utils/parsers/custom_nullable_int_parser.dart"
+    - apply_to_type: "bool"
+      parser_name: "CustomBoolParser"
+      parser_absolute_path: "package:your_package/lib/utils/parsers/custom_bool_parser.dart"
+
   # Optional. Skip parameters with names.
   skipped_parameters:
     - "X-Some-Token"

swagger_parser/lib/src/config/swp_config.dart

@@ -1,6 +1,7 @@
 import 'package:args/args.dart';
 import 'package:swagger_parser/src/config/config_exception.dart';
 import 'package:swagger_parser/src/generator/config/generator_config.dart';
+import 'package:swagger_parser/src/generator/model/field_parser.dart';
 import 'package:swagger_parser/src/generator/model/json_serializer.dart';
 import 'package:swagger_parser/src/generator/model/programming_language.dart';
 import 'package:swagger_parser/src/parser/swagger_parser_core.dart';
@@ -50,6 +51,7 @@ class SWPConfig {
     this.inferRequiredFromNullable = false,
     this.useFlutterCompute = false,
     this.generateUrlsConstants = false,
+    this.fieldParsers = const [],
   });
 
   /// Internal constructor of [SWPConfig]
@@ -93,6 +95,7 @@ class SWPConfig {
     required this.inferRequiredFromNullable,
     required this.useFlutterCompute,
     required this.generateUrlsConstants,
+    required this.fieldParsers,
     this.fallbackUnion,
   });
 
@@ -348,12 +351,38 @@ class SWPConfig {
     final generateUrlsConstants = yamlMap['generate_urls_constants'] as bool? ??
         rootConfig?.generateUrlsConstants;
 
+    final rawFieldParsers = yamlMap['field_parsers'] as YamlList?;
+    List<FieldParser>? fieldParsers;
+    if (rawFieldParsers != null) {
+      fieldParsers = [];
+      for (final p in rawFieldParsers) {
+        if (p is! YamlMap ||
+            p['apply_to_type'] is! String ||
+            p['parser_name'] is! String ||
+            p['parser_absolute_path'] is! String) {
+          throw const ConfigException(
+            "Config parameter 'field_parsers' values must be List of maps with 'apply_to_type', 'parser_name', and 'parser_absolute_path'.",
+          );
+        }
+        fieldParsers.add(
+          FieldParser(
+            applyToType: p['apply_to_type'].toString(),
+            parserName: p['parser_name'].toString(),
+            parserAbsolutePath: p['parser_absolute_path'].toString(),
+          ),
+        );
+      }
+    } else if (rootConfig?.fieldParsers != null) {
+      fieldParsers = List.from(rootConfig!.fieldParsers);
+    }
+
     // Default config
     final dc = SWPConfig(name: name, outputDirectory: outputDirectory);
 
     return SWPConfig._(
       schemaPath: schemaPath,
       schemaUrl: schemaUrl,
+      fieldParsers: fieldParsers ?? dc.fieldParsers,
       outputDirectory: outputDirectory,
       name: name,
       pathMethodName: pathMethodName ?? dc.pathMethodName,
@@ -617,6 +646,15 @@ class SWPConfig {
   /// Optional. Set `true` to generate URL constants for all endpoints.
   final bool generateUrlsConstants;
 
+  /// {@template field_parsers}
+  /// DART ONLY
+  /// Optional. Set field parsers.
+  ///
+  /// Field parsers are used to parse specific fields of a DTO.
+  ///
+  /// {@endtemplate}
+  final List<FieldParser> fieldParsers;
+
   /// Convert [SWPConfig] to [GeneratorConfig]
   GeneratorConfig toGeneratorConfig() {
     return GeneratorConfig(
@@ -647,6 +685,7 @@ class SWPConfig {
       includeIfNull: includeIfNull,
       useFlutterCompute: useFlutterCompute,
       generateUrlsConstants: generateUrlsConstants,
+      fieldParsers: fieldParsers,
     );
   }
 

swagger_parser/lib/src/generator/config/generator_config.dart

@@ -1,3 +1,4 @@
+import 'package:swagger_parser/src/generator/model/field_parser.dart';
 import 'package:swagger_parser/src/generator/model/json_serializer.dart';
 import 'package:swagger_parser/src/generator/model/programming_language.dart';
 import 'package:swagger_parser/src/parser/model/replacement_rule.dart';
@@ -33,6 +34,7 @@ class GeneratorConfig {
     this.includeIfNull = false,
     this.useFlutterCompute = false,
     this.generateUrlsConstants = false,
+    this.fieldParsers = const [],
   });
 
   /// Optional. Set API name for folder and export file or merged output file
@@ -159,4 +161,7 @@ class GeneratorConfig {
   /// DART/FLUTTER ONLY
   /// Optional. Set `true` to generate URL constants for all endpoints.
   final bool generateUrlsConstants;
+
+  /// {@macro field_parsers}
+  final List<FieldParser> fieldParsers;
 }

swagger_parser/lib/src/generator/generator/fill_controller.dart

@@ -28,6 +28,7 @@ final class FillController {
           dataClass,
           jsonSerializer: config.jsonSerializer,
           enumsToJson: config.enumsToJson,
+          fieldParsers: config.fieldParsers,
           unknownEnumValue: config.unknownEnumValue,
           markFilesAsGenerated: config.markFilesAsGenerated,
           generateValidator: config.generateValidator,

swagger_parser/lib/src/generator/model/field_parser.dart

@@ -0,0 +1,25 @@
+/// {@template field_parser}
+/// Configuration for a field parser
+/// {@endtemplate}
+class FieldParser {
+  /// {@macro field_parser}
+  const FieldParser({
+    required this.applyToType,
+    required this.parserName,
+    required this.parserAbsolutePath,
+  });
+
+  /// The type of the field to apply the parser to
+  final String applyToType;
+
+  /// The name of the parser
+  final String parserName;
+
+  /// The absolute path to the parser
+  final String parserAbsolutePath;
+
+  @override
+  String toString() {
+    return 'FieldParser(applyToType: $applyToType, parserName: $parserName, parserAbsolutePath: $parserAbsolutePath)';
+  }
+}

swagger_parser/lib/src/generator/model/programming_language.dart

@@ -1,3 +1,4 @@
+import 'package:swagger_parser/src/generator/model/field_parser.dart';
 import 'package:swagger_parser/src/generator/model/generated_file.dart';
 import 'package:swagger_parser/src/generator/model/json_serializer.dart';
 import 'package:swagger_parser/src/generator/templates/dart_dart_mappable_dto_template.dart';
@@ -51,6 +52,7 @@ enum ProgrammingLanguage {
     required bool useMultipartFile,
     required bool dartMappableConvenientWhen,
     required bool includeIfNull,
+    required List<FieldParser> fieldParsers,
     bool useFlutterCompute = false,
     String? fallbackUnion,
   }) {
@@ -84,6 +86,7 @@ enum ProgrammingLanguage {
                 dataClass,
                 markFileAsGenerated: markFilesAsGenerated,
                 useMultipartFile: useMultipartFile,
+                fieldParsers: fieldParsers,
                 includeIfNull: includeIfNull,
                 useFlutterCompute: useFlutterCompute,
                 fallbackUnion: fallbackUnion,

swagger_parser/lib/src/generator/templates/dart_json_serializable_dto_template.dart

@@ -1,4 +1,5 @@
 import 'package:collection/collection.dart';
+import 'package:swagger_parser/src/generator/model/field_parser.dart';
 import 'package:swagger_parser/src/generator/model/programming_language.dart';
 import 'package:swagger_parser/src/parser/model/normalized_identifier.dart';
 import 'package:swagger_parser/src/parser/swagger_parser_core.dart';
@@ -11,6 +12,7 @@ String dartJsonSerializableDtoTemplate(
   required bool markFileAsGenerated,
   required bool useMultipartFile,
   required bool includeIfNull,
+  required List<FieldParser> fieldParsers,
   bool useFlutterCompute = false,
   String? fallbackUnion,
 }) {
@@ -33,17 +35,32 @@ String dartJsonSerializableDtoTemplate(
       useFlutterCompute ? _generateFlutterComputeSerializer(className) : '';
   final asyncImport = useFlutterCompute ? "import 'dart:async';\n\n" : '';
 
+  final actualFieldParsers = fieldParsers
+      .where(
+        (e) => dataClass.parameters.any(
+          (p) =>
+              _renameUnionTypes(
+                p.toSuitableType(
+                  ProgrammingLanguage.dart,
+                  useMultipartFile: useMultipartFile,
+                ),
+              ) ==
+              e.applyToType,
+        ),
+      )
+      .toList();
+
   return '''
 $asyncImport${ioImport(dataClass.parameters, useMultipartFile: useMultipartFile)}import 'package:json_annotation/json_annotation.dart';
-${dartImports(imports: _filterUnionImportsForNonUnion(dataClass))}
+${dartImports(imports: _filterUnionImportsForNonUnion(dataClass))}${actualFieldParsers.isEmpty ? '' : '\n${actualFieldParsers.map((e) => "import '${e.parserAbsolutePath}';").toSet().join('\n')}'}
 part '$classNameSnake.g.dart';
 
 ${descriptionComment(dataClass.description)}@JsonSerializable()
 class $className {
   const $className(${dataClass.parameters.isNotEmpty ? '{' : ''}${_parametersInConstructor(dataClass.parameters, includeIfNull)}${dataClass.parameters.isNotEmpty ? '\n  }' : ''});
 
   factory $className.fromJson(Map<String, Object?> json) => _\$${className}FromJson(json);
-  ${_parametersInClass(dataClass.parameters, useMultipartFile, includeIfNull)}${dataClass.parameters.isNotEmpty ? '\n' : ''}
+  ${_parametersInClass(dataClass.parameters, useMultipartFile, includeIfNull, actualFieldParsers)}${dataClass.parameters.isNotEmpty ? '\n' : ''}
   Map<String, Object?> toJson() => _\$${className}ToJson(this);
 }
 $serializerClass''';
@@ -395,14 +412,17 @@ String _parametersInClass(
   Set<UniversalType> parameters,
   bool useMultipartFile,
   bool includeIfNull,
+  List<FieldParser> fieldParsers,
 ) =>
-    parameters
-        .mapIndexed(
-          (i, e) =>
-              '\n${i != 0 && (e.description?.isNotEmpty ?? false) ? '\n' : ''}${descriptionComment(e.description, tab: '  ')}'
-              '${_jsonKey(e, includeIfNull)}  final ${_renameUnionTypes(e.toSuitableType(ProgrammingLanguage.dart, useMultipartFile: useMultipartFile))} ${e.name};',
-        )
-        .join();
+    parameters.mapIndexed((i, e) {
+      final dartType = _renameUnionTypes(e.toSuitableType(
+          ProgrammingLanguage.dart,
+          useMultipartFile: useMultipartFile));
+      final fieldParser =
+          fieldParsers.firstWhereOrNull((f) => f.applyToType == dartType);
+      return '\n${i != 0 && (e.description?.isNotEmpty ?? false) ? '\n' : ''}${descriptionComment(e.description, tab: '  ')}'
+          '${fieldParser != null ? '\t@${fieldParser.parserName}()\n' : ''}${_jsonKey(e, includeIfNull)}  final ${_renameUnionTypes(e.toSuitableType(ProgrammingLanguage.dart, useMultipartFile: useMultipartFile))} ${e.name};';
+    }).join();
 
 String _parametersInConstructor(
     Set<UniversalType> parameters, bool includeIfNull) {

swagger_parser/lib/swagger_parser.dart

@@ -11,6 +11,7 @@ export 'src/generator/exception/generator_exception.dart';
 export 'src/generator/generator/fill_controller.dart';
 export 'src/generator/generator/generator.dart';
 export 'src/generator/generator/generator_processor.dart';
+export 'src/generator/model/field_parser.dart';
 export 'src/generator/model/generated_file.dart';
 export 'src/generator/model/json_serializer.dart';
 export 'src/generator/model/programming_language.dart';