Converter class

Fluent wrapper for chained type conversions with navigation and fallbacks.

Converter provides a chainable API for extracting and converting values from nested data structures. It is the primary way to convert values fluently via the value.convert.toInt() syntax.

Basic Usage

final json = {'user': {'age': '25'}};
final age = json.convert.fromMap('user').fromMap('age').toInt();

With Defaults

final value = data.convert.withDefault(0).toInt(); // Falls back to 0

With Custom Pre-Processing

final value = raw.convert.withConverter((v) => v?.trim()).string();

Unlike Convert, which is stateless, Converter wraps a value and allows incremental navigation through nested structures. Configuration set via withDefault or withConverter persists through navigation methods.

See also:

• Convert for stateless conversion methods.
• ConvertObjectExtension for the .convert getter.

Constructors

Converter(Object? _value, {Object? defaultValue, DynamicConverter? customConverter})

Creates a converter wrapping _value with optional fallback and pre-processing.

const

Properties

decoded → Converter

Explicitly decodes a JSON string into a Dart object (Map, List, etc.).

no setter

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

fromList(int index) → Converter

Extracts a value from a List using the specified index.

fromMap(Object? key) → Converter

Extracts a value from a Map using the specified key.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

string({dynamic mapKey, int? listIndex, String? defaultValue, DynamicConverter<String>? converter}) → String

Converts to String, mirroring Convert.string.

to<T>() → T

Converts the wrapped value to type T.

toBigInt({dynamic mapKey, int? listIndex, BigInt? defaultValue, DynamicConverter<BigInt>? converter}) → BigInt

Converts to BigInt, mirroring Convert.toBigInt.

toBigIntOr(BigInt defaultValue, {dynamic mapKey, int? listIndex, DynamicConverter<BigInt>? converter}) → BigInt

Converts to BigInt, falling back to defaultValue on failure.

toBool({dynamic mapKey, int? listIndex, bool? defaultValue, DynamicConverter<bool>? converter}) → bool

Converts to bool, mirroring Convert.toBool.

toBoolOr(bool defaultValue, {dynamic mapKey, int? listIndex, DynamicConverter<bool>? converter}) → bool

Converts to bool, falling back to defaultValue on failure.

toDateTime({dynamic mapKey, int? listIndex, String? format, String? locale, bool autoDetectFormat = false, bool useCurrentLocale = false, bool utc = false, DateTime? defaultValue, DynamicConverter<DateTime>? converter}) → DateTime

Converts to DateTime, mirroring Convert.toDateTime.

toDateTimeOr(DateTime defaultValue, {dynamic mapKey, int? listIndex, String? format, String? locale, bool autoDetectFormat = false, bool useCurrentLocale = false, bool utc = false, DynamicConverter<DateTime>? converter}) → DateTime

Converts to DateTime, falling back to defaultValue on failure.

toDouble({dynamic mapKey, int? listIndex, String? format, String? locale, double? defaultValue, DynamicConverter<double>? converter}) → double

Converts to double, mirroring Convert.toDouble.

toDoubleOr(double defaultValue, {dynamic mapKey, int? listIndex, String? format, String? locale, DynamicConverter<double>? converter}) → double

Converts to double, falling back to defaultValue on failure.

toEnum<T extends Enum>({required T parser(dynamic), dynamic mapKey, int? listIndex, T? defaultValue, Map<String, dynamic>? debugInfo}) → T

Converts to T using parser, mirroring Convert.toEnum.

toInt({dynamic mapKey, int? listIndex, String? format, String? locale, int? defaultValue, DynamicConverter<int>? converter}) → int

Converts to int, mirroring Convert.toInt.

toIntOr(int defaultValue, {dynamic mapKey, int? listIndex, String? format, String? locale, DynamicConverter<int>? converter}) → int

Converts to int, falling back to defaultValue when conversion fails.

toList<T>({dynamic mapKey, int? listIndex, List<T>? defaultValue, DynamicConverter<T>? elementConverter}) → List<T>

Converts to List, optionally transforming each item.

toMap<K, V>({dynamic mapKey, int? listIndex, Map<K, V>? defaultValue, DynamicConverter<K>? keyConverter, DynamicConverter<V>? valueConverter}) → Map<K, V>

Converts to Map, allowing converters for keys and values.

toNum({dynamic mapKey, int? listIndex, String? format, String? locale, num? defaultValue, DynamicConverter<num>? converter}) → num

Converts to num, mirroring Convert.toNum.

toNumOr(num defaultValue, {dynamic mapKey, int? listIndex, String? format, String? locale, DynamicConverter<num>? converter}) → num

Converts to num, falling back to defaultValue on conversion failure.

toOr<T>(T defaultValue) → T

Converts the wrapped value to type T, falling back to defaultValue on failure.

toSet<T>({dynamic mapKey, int? listIndex, Set<T>? defaultValue, DynamicConverter<T>? elementConverter}) → Set<T>

Converts to Set, optionally transforming each item.

toString() → String

Overrides Object.toString using the conversion logic.

override

toStringOr(String defaultValue, {dynamic mapKey, int? listIndex, DynamicConverter<String>? converter}) → String

Converts to String, falling back to defaultValue when conversion fails.

toUri({dynamic mapKey, int? listIndex, Uri? defaultValue, DynamicConverter<Uri>? converter}) → Uri

Converts to Uri, mirroring Convert.toUri.

toUriOr(Uri defaultValue, {dynamic mapKey, int? listIndex, DynamicConverter<Uri>? converter}) → Uri

Converts to Uri, falling back to defaultValue on failure.

tryTo<T>() → T?

Attempts to convert the wrapped value to type T.

tryToBigInt({dynamic mapKey, int? listIndex, BigInt? defaultValue, DynamicConverter<BigInt>? converter}) → BigInt?

Converts to BigInt without throwing, mirroring Convert.tryToBigInt.

tryToBool({dynamic mapKey, int? listIndex, bool? defaultValue, DynamicConverter<bool>? converter}) → bool?

Converts to bool without throwing, mirroring Convert.tryToBool.

tryToDateTime({dynamic mapKey, int? listIndex, String? format, String? locale, bool autoDetectFormat = false, bool useCurrentLocale = false, bool utc = false, DateTime? defaultValue, DynamicConverter<DateTime>? converter}) → DateTime?

Converts to DateTime without throwing, mirroring Convert.tryToDateTime.

tryToDouble({dynamic mapKey, int? listIndex, String? format, String? locale, double? defaultValue, DynamicConverter<double>? converter}) → double?

Converts to double without throwing, mirroring Convert.tryToDouble.

tryToEnum<T extends Enum>({required T parser(dynamic), dynamic mapKey, int? listIndex, T? defaultValue, Map<String, dynamic>? debugInfo}) → T?

Converts to T without throwing, mirroring Convert.tryToEnum.

tryToInt({dynamic mapKey, int? listIndex, String? format, String? locale, int? defaultValue, DynamicConverter<int>? converter}) → int?

Converts to int without throwing, mirroring Convert.tryToInt.

tryToList<T>({dynamic mapKey, int? listIndex, List<T>? defaultValue, DynamicConverter<T>? elementConverter}) → List<T>?

Converts to List without throwing, returning null when conversion fails.

tryToMap<K, V>({dynamic mapKey, int? listIndex, Map<K, V>? defaultValue, DynamicConverter<K>? keyConverter, DynamicConverter<V>? valueConverter}) → Map<K, V>?

Converts to Map without throwing, returning null on failure.

tryToNum({dynamic mapKey, int? listIndex, String? format, String? locale, num? defaultValue, DynamicConverter<num>? converter}) → num?

Converts to num without throwing, mirroring Convert.tryToNum.

tryToSet<T>({dynamic mapKey, int? listIndex, Set<T>? defaultValue, DynamicConverter<T>? elementConverter}) → Set<T>?

Converts to Set without throwing, returning null on failure.

tryToString({dynamic mapKey, int? listIndex, String? defaultValue, DynamicConverter<String>? converter}) → String?

Converts to String without throwing, mirroring Convert.tryToString.

tryToUri({dynamic mapKey, int? listIndex, Uri? defaultValue, DynamicConverter<Uri>? converter}) → Uri?

Converts to Uri without throwing, mirroring Convert.tryToUri.

withConverter(DynamicConverter converter) → Converter

Applies a custom transformation to the value before any conversion attempt.

withDefault(Object? value) → Converter

Configures a default value to be returned if the subsequent conversion operation fails.

Operators

operator ==(Object other) → bool

The equality operator.

inherited