feat: user defined types

slang/README.md

@@ -956,6 +956,27 @@ Or adjust built-in formats:
 }
 ```
 
+To avoid repetition, you can define custom types via `@@types`.
+Please note that the types are locale-specific. If you use [namespaces](#-namespaces), all definitions are merged.
+
+```json
+{
+  "@@types": {
+    "price": "currency(symbol: 'USD')",
+    "dateOnly": "DateFormat('MM/dd/yyyy')"
+  },
+  "account": "You have {amount: price} in your account",
+  "today": "Today is {today: dateOnly}",
+  "tomorrow": "Tomorrow is {tomorrow: dateOnly}"
+}
+```
+
+```dart
+String a = t.account(amount: 1234.56); // You have $1,234.56 in your account
+String b = t.today(today: DateTime(2023, 3, 2)); // Today is 03/02/2023
+String c = t.tomorrow(tomorrow: DateTime(2023, 3, 5)); // Tomorrow is 03/05/2023
+```
+
 ### ➤ Interfaces
 
 Often, multiple objects have the same attributes. You can create a common super class for that.

slang/lib/node.dart

@@ -1 +1,2 @@
+export 'package:slang/src/api/formatter.dart';
 export 'package:slang/src/builder/model/node.dart';

slang/lib/src/api/formatter.dart

@@ -0,0 +1,26 @@
+import 'package:intl/intl.dart';
+
+class ValueFormatter {
+  /// Is either [NumberFormat] or [DateFormat].
+  /// Unfortunately, there is no super class for both.
+  final Object Function() _formatter;
+
+  /// The actual formatter.
+  /// We delay the initialization to ensure that intl is already initialized
+  /// by Flutter before we create the formatter.
+  late final Object formatter = _formatter();
+
+  ValueFormatter(this._formatter);
+
+  /// Formats the given [value] with the formatter.
+  String format(Object value) {
+    switch (formatter) {
+      case NumberFormat formatter:
+        return formatter.format(value as num);
+      case DateFormat formatter:
+        return formatter.format(value as DateTime);
+      default:
+        throw Exception('Unknown formatter: $formatter');
+    }
+  }
+}

slang/lib/src/api/locale.dart

@@ -1,3 +1,4 @@
+import 'package:slang/src/api/formatter.dart';
 import 'package:slang/src/api/pluralization.dart';
 import 'package:slang/src/builder/model/node.dart';
 
@@ -17,6 +18,7 @@ class TranslationMetadata<E extends BaseAppLocale<E, T>,
   final Map<String, Node> overrides;
   final PluralResolver? cardinalResolver;
   final PluralResolver? ordinalResolver;
+  final Map<String, ValueFormatter> types;
 
   /// The secret.
   /// Used to decrypt obfuscated translation strings.
@@ -29,6 +31,7 @@ class TranslationMetadata<E extends BaseAppLocale<E, T>,
     required this.overrides,
     required this.cardinalResolver,
     required this.ordinalResolver,
+    this.types = const {},
     this.s = 0,
   });
 

slang/lib/src/builder/builder/translation_model_builder.dart

@@ -1,6 +1,7 @@
 import 'dart:collection';
 
 import 'package:collection/collection.dart';
+import 'package:slang/src/builder/builder/text/l10n_parser.dart';
 import 'package:slang/src/builder/model/build_model_config.dart';
 import 'package:slang/src/builder/model/context_type.dart';
 import 'package:slang/src/builder/model/enums.dart';
@@ -16,11 +17,13 @@ class BuildModelResult {
   final ObjectNode root; // the actual strings
   final List<Interface> interfaces; // detected interfaces
   final List<PopulatedContextType> contexts; // detected context types
+  final Map<String, String> types; // detected types, values are rendered as is
 
   BuildModelResult({
     required this.root,
     required this.interfaces,
     required this.contexts,
+    required this.types,
   });
 }
 
@@ -71,6 +74,28 @@ class TranslationModelBuilder {
         context.enumName: context.toPending(),
     };
 
+    final types = <String, FormatTypeInfo>{};
+    final typesNode = map['@@types'];
+    if (typesNode != null && typesNode is Map<String, dynamic>) {
+      for (final entry in typesNode.entries) {
+        final key = entry.key;
+        final value = entry.value;
+        if (value is String) {
+          final typeInfo = parseL10n(
+            locale: locale,
+            paramName: 'value',
+            type: value,
+          );
+          if (typeInfo != null) {
+            types[key] = FormatTypeInfo(
+              paramType: typeInfo.paramType,
+              implementation: typeInfo.format,
+            );
+          }
+        }
+      }
+    }
+
     // 1st iteration: Build nodes according to given map
     //
     // Linked Translations:
@@ -79,6 +104,7 @@ class TranslationModelBuilder {
     // Reason: Not all TextNodes are built, so final parameters are unknown
     final resultNodeTree = _parseMapNode(
       locale: locale,
+      types: types,
       parentPath: '',
       parentRawPath: '',
       curr: map,
@@ -214,6 +240,10 @@ class TranslationModelBuilder {
                 generateEnum: c.generateEnum,
               ))
           .toList(),
+      types: {
+        for (final entry in types.entries)
+          entry.key: entry.value.implementation,
+      },
     );
   }
 }
@@ -222,6 +252,7 @@ class TranslationModelBuilder {
 /// and returns the node model.
 Map<String, Node> _parseMapNode({
   required I18nLocale locale,
+  required Map<String, FormatTypeInfo> types,
   required String parentPath,
   required String parentRawPath,
   required Map<String, dynamic> curr,
@@ -267,6 +298,7 @@ Map<String, Node> _parseMapNode({
               rawPath: currRawPath,
               modifiers: modifiers,
               locale: locale,
+              types: types,
               raw: value.toString(),
               comment: comment,
               shouldEscape: shouldEscapeText,
@@ -278,6 +310,7 @@ Map<String, Node> _parseMapNode({
               rawPath: currRawPath,
               modifiers: modifiers,
               locale: locale,
+              types: types,
               raw: value.toString(),
               comment: comment,
               shouldEscape: shouldEscapeText,
@@ -297,6 +330,7 @@ Map<String, Node> _parseMapNode({
         };
         children = _parseMapNode(
           locale: locale,
+          types: types,
           parentPath: currPath,
           parentRawPath: currRawPath,
           curr: listAsMap,
@@ -323,6 +357,7 @@ Map<String, Node> _parseMapNode({
         // key: { ...value }
         children = _parseMapNode(
           locale: locale,
+          types: types,
           parentPath: currPath,
           parentRawPath: currRawPath,
           curr: value,
@@ -379,6 +414,7 @@ Map<String, Node> _parseMapNode({
             // rebuild children as RichText
             digestedMap = _parseMapNode(
               locale: locale,
+              types: types,
               parentPath: currPath,
               parentRawPath: currRawPath,
               curr: {
@@ -921,3 +957,13 @@ extension on BuildModelConfig {
     );
   }
 }
+
+class FormatTypeInfo {
+  final String paramType; // num or DateTime
+  final String implementation; // raw string that will be rendered as is
+
+  FormatTypeInfo({
+    required this.paramType,
+    required this.implementation,
+  });
+}

slang/lib/src/builder/builder/translation_model_list_builder.dart

@@ -42,6 +42,7 @@ class TranslationModelListBuilder {
           root: baseResult.root,
           contexts: baseResult.contexts,
           interfaces: baseResult.interfaces,
+          types: baseResult.types,
         );
       } else {
         final result = TranslationModelBuilder.build(
@@ -57,6 +58,7 @@ class TranslationModelListBuilder {
           root: result.root,
           contexts: result.contexts,
           interfaces: result.interfaces,
+          types: result.types,
         );
       }
     }).toList()

slang/lib/src/builder/generator/generate_translations.dart

@@ -203,6 +203,15 @@ void _generateClass(
     buffer.writeln('\t\t    overrides: overrides ?? {},');
     buffer.writeln('\t\t    cardinalResolver: cardinalResolver,');
     buffer.writeln('\t\t    ordinalResolver: ordinalResolver,');
+    if (localeData.types.isNotEmpty) {
+      buffer.writeln('\t\t    types: {');
+      for (final entry in localeData.types.entries) {
+        buffer.writeln(
+          '\t\t      \'${entry.key}\': ValueFormatter(() => ${entry.value.substring(0, entry.value.length - 14)}),',
+        );
+      }
+      buffer.writeln('\t\t    },');
+    }
     if (config.obfuscation.enabled) {
       final String method;
       final List<int> parts;

slang/lib/src/builder/model/i18n_data.dart

@@ -12,13 +12,15 @@ class I18nData {
   final ObjectNode root; // the actual strings
   final List<PopulatedContextType> contexts; // detected context types
   final List<Interface> interfaces; // detected interfaces
+  final Map<String, String> types; // detected types, values are rendered as is
 
   I18nData({
     required this.base,
     required this.locale,
     required this.root,
     required this.contexts,
     required this.interfaces,
+    required this.types,
   });
 
   /// sorts base locale first, then alphabetically

slang/lib/src/builder/model/node.dart

@@ -1,5 +1,6 @@
 import 'package:slang/src/builder/builder/text/l10n_parser.dart';
 import 'package:slang/src/builder/builder/text/param_parser.dart';
+import 'package:slang/src/builder/builder/translation_model_builder.dart';
 import 'package:slang/src/builder/model/context_type.dart';
 import 'package:slang/src/builder/model/enums.dart';
 import 'package:slang/src/builder/model/i18n_locale.dart';
@@ -218,6 +219,9 @@ abstract class TextNode extends Node implements LeafNode {
   /// The locale of the text node
   final I18nLocale locale;
 
+  /// User-defined types for the locale
+  final Map<String, FormatTypeInfo> types;
+
   /// The original string
   final String raw;
 
@@ -251,6 +255,7 @@ abstract class TextNode extends Node implements LeafNode {
     required super.modifiers,
     required super.comment,
     required this.locale,
+    required this.types,
     required this.raw,
     required this.shouldEscape,
     required this.interpolation,
@@ -297,6 +302,7 @@ class StringTextNode extends TextNode {
     required super.rawPath,
     required super.modifiers,
     required super.locale,
+    required super.types,
     required super.raw,
     required super.comment,
     required super.shouldEscape,
@@ -306,6 +312,7 @@ class StringTextNode extends TextNode {
   }) {
     final parsedResult = _parseInterpolation(
       locale: locale,
+      types: types,
       raw: shouldEscape ? _escapeContent(raw, interpolation) : raw,
       interpolation: interpolation,
       defaultType: 'Object',
@@ -341,6 +348,7 @@ class StringTextNode extends TextNode {
       rawPath: rawPath,
       modifiers: modifiers,
       locale: locale,
+      types: types,
       raw: raw,
       comment: comment,
       shouldEscape: shouldEscape,
@@ -392,6 +400,7 @@ class RichTextNode extends TextNode {
     required super.rawPath,
     required super.modifiers,
     required super.locale,
+    required super.types,
     required super.raw,
     required super.comment,
     required super.shouldEscape,
@@ -401,6 +410,7 @@ class RichTextNode extends TextNode {
   }) {
     final rawParsedResult = _parseInterpolation(
       locale: locale,
+      types: types,
       raw: shouldEscape ? _escapeContent(raw, interpolation) : raw,
       interpolation: interpolation,
       defaultType: 'ignored',
@@ -477,6 +487,7 @@ class RichTextNode extends TextNode {
       rawPath: rawPath,
       modifiers: modifiers,
       locale: locale,
+      types: types,
       raw: raw,
       comment: comment,
       shouldEscape: shouldEscape,
@@ -542,6 +553,7 @@ class _ParseInterpolationResult {
 
 _ParseInterpolationResult _parseInterpolation({
   required I18nLocale locale,
+  required Map<String, FormatTypeInfo> types,
   required String raw,
   required StringInterpolation interpolation,
   required String defaultType,
@@ -558,6 +570,12 @@ _ParseInterpolationResult _parseInterpolation({
       caseStyle: paramCase,
     );
 
+    final existingType = types[parsedParam.paramType];
+    if (existingType != null) {
+      params[parsedParam.paramName] = existingType.paramType;
+      return '\${_root.\$meta.types[\'${parsedParam.paramType}\']!.format(${parsedParam.paramName})}';
+    }
+
     final parsedL10n = parseL10n(
       locale: locale,
       paramName: parsedParam.paramName,

slang/lib/src/builder/model/translation_map.dart

@@ -25,6 +25,16 @@ class TranslationMap {
     }
 
     _internalMap[locale]![namespace] = translations;
+
+    // Copy types of each namespace to the global types map,
+    // merging them with existing types.
+    final typesMap = translations['@@types'] as Map<String, dynamic>?;
+    if (typesMap != null) {
+      _internalMap[locale]!['@@types'] = {
+        ...?_internalMap[locale]!['@@types'],
+        ...typesMap,
+      };
+    }
   }
 
   /// Return all locales specified in this map

slang/test/unit/model/i18n_data_test.dart

@@ -17,6 +17,7 @@ I18nData _i18n(String locale, [bool base = false]) {
     ),
     contexts: [],
     interfaces: [],
+    types: {},
   );
 }
 

slang/test/util/text_node_builder.dart

@@ -15,6 +15,7 @@ StringTextNode textNode(
     rawPath: '',
     modifiers: {},
     locale: _locale,
+    types: {},
     raw: raw,
     comment: null,
     interpolation: interpolation,
@@ -36,6 +37,7 @@ RichTextNode richTextNode(
     modifiers: {},
     comment: null,
     locale: _locale,
+    types: {},
     raw: raw,
     interpolation: interpolation,
     paramCase: paramCase,