dart:convert

JsonDecoder class

This class parses JSON strings and builds the corresponding objects.

A JSON input must be the JSON encoding of a single JSON value, which can be a list or map containing other values.

Throws FormatException if the input is not valid JSON text.

Example:

const JsonDecoder decoder = JsonDecoder();

const String jsonString = '''
  {
    "data": [{"text": "foo", "value": 1 },
             {"text": "bar", "value": 2 }],
    "text": "Dart"
  }
''';

final Map<String, dynamic> object = decoder.convert(jsonString);

final item = object['data'][0];
print(item['text']); // foo
print(item['value']); // 1

print(object['text']); // Dart

When used as a StreamTransformer, the input stream may emit multiple strings. The concatenation of all of these strings must be a valid JSON encoding of a single JSON value.

Inheritance

• Object
• StreamTransformerBase<String, Object?>
• Converter<String, Object?>
• JsonDecoder

Constructors

JsonDecoder([Object? reviver(Object? key, Object? value)?])

const

Constructs a new JsonDecoder.

Properties

hashCode → int

read-only, inherited

The hash code for this object.

runtimeType → Type

read-only, inherited

A representation of the runtime type of the object.

Methods

bind(Stream<String> stream) → Stream<Object?>

override

Transforms the provided stream.

cast<RS, RT>() → Converter<RS, RT>

inherited

Provides a Converter<RS, RT> view of this stream transformer.

convert(String input) → dynamic

override

Converts the given JSON-string input to its corresponding object.

fuse<TT>(Converter<Object?, TT> other) → Converter<String, TT>

inherited

Fuses this with other.

noSuchMethod(Invocation invocation) → dynamic

inherited

Invoked when a non-existent method or property is accessed.

startChunkedConversion(Sink<Object?> sink) → StringConversionSink

override

Starts a conversion from a chunked JSON string to its corresponding object.

toString() → String

inherited

A string representation of this object.

Operators

operator ==(Object other) → bool

inherited

The equality operator.