PowerJSON is a fork of the smallest, fastest polymorphic JSON serializer--fastJSON.

Please read the article about fastJSON here.

The following features are added to the original fastJSON.

• Rename serialized members.
• Rename serialized Enum values.
• Deserializing non-public types.
• Serializing and deserializing non-public members.
• Polymorphic serialization without JSON extensions.
• Write out additional key-value pairs in the serialized JSON.
• Conditional serialization.
• Noninvasive control over serialization.
• Easiest implemetation of customized serialization and deserialization.
• A comprehensive documentation.

The newly introduced classes and interfaces have brought more control onto each aspect in serialization.

• SerializationManager: Caches the reflection result and controls the serialization. Supports non-invasive control over serialization.
• IReflectionController: Controls every possible aspect in reflection for serialization.
• IJsonInterceptor: Intercepts JSON serialization and enables conditional serialization.
• IJsonConverter: Converts between various value types.
• JsonConverter<TOriginal,TSerialized>: A base class which implements IJsonConverter and simplifies the data conversion.

This fork has empowered fastJSON to serialize and deserialize objects with additional attribute types. The attributes are listed below:

• JsonInterceptorAttribute: 1) controls the procedure of serialization. 2) allows conditional serialization. 3) allows writing out extra key-value pairs in the serialized object.
• JsonFieldAttribute: 1) controls the name of the serialized field or property. 2) allows serializing interface or abstract types with the Type and Name conbination in the attribute.
• JsonIncludeAttribute: 1) explicitly controls whether a field or property is serialized or not. 2) allows serializing readonly property even when the ShowReadOnlyProperties setting is turned off.
• JsonConverterAttribute: allows transforming data before serialization.
• JsonEnumValueAttribute: controls the serialized literal name of an Enum value.
• JsonSerializableAttribute: enables serializing and deserializing non-public types or members.
• JsonNonSerializedValueAttribute: prevents specified member value from serializing.
• JsonContainerAttribute: puts enumerable items into a field named by this attribute to fully serialize types implementing IEnumerable.

Some .NET built-in attributes are also supported.

• DefaultValueAttribute: values equal to DefaultValueAttribute.Value are not serialized.
• ReadOnlyAttribute: values are not deserialized when ReadOnlyAttribute.IsReadOnly is set to true.
• DataContractAttribute
• DataMemberAttribute: Currently only the Name setting is supported, other settings such as Order, IsRequired are not supported.
• EnumMemberAttribute
• IgnoreDataMemberAttribute

XML serialization attributes are optionally supported (listed below). By default, the support is disabled and can be accessed by creating a new SerializationManager with a JsonReflectionController which has that option turned on.

• XmlElementAttribute
• XmlAttributeAttribute
• XmlArrayAttribute
• XmlEnumAttribute
• XmlIgnoreAttribute

This fork introduced the following settings in JSONParameters:

• NamingConvention: control the naming convention of serialized fields and properties. It has added support for camel-case, uppercase names.
• SerializeStaticMembers: control whether static fields or properties should be serialized. (2015-4-2)
• ShowReadOnlyFields: control whether readonly fields should be serialized. (2015-4-7)
• SerializeEmptyCollections: control whether zero length collections, arrays, lists, dictionaries, etc. are serialized. (2015-4-25)

This fork also fixed some issues in the original fastJSON project:

• The serialized Enum value could be incorrect when the underlying type is Int64 or UInt64.
• Null values were ignored in deserialization (when the constructor initialize the value of the member, in deserialization, the null value should not be ignored and set the member to null).
• Multi-value items in NameValueCollection were not serialized correctly.
• Serializing TimeSpan type could cause application stack overflow. (2015-4-2)
• Read-only static fields were serialized regardless ShowReadOnlyProperties was turned off. (2015-4-7)
• ShowReadOnlyProperties was not in effect for the same type after change. (2015-4-7)
• Deserialization on Dictionary<N, List<V>> type could fail. (2015-4-9)
• "Release" compiled edition did not support dynamic types.
• Multi-demensional arrays could not be deserialized. (2015-4-25)
• List<T[]> list could not be deserialized. (2015-4-27)
• HashSet<T> could not be serialized. (2015-5-13)
• Types implementing IEnumerable could not be fully serialized. (2015-8-25)

• Performance has been more thoroughly optimized. It is faster than the fastest :)
• The Beautify method of JSON has introduced a new parameter: decodeUnicode, which allows decode "\uXXXX" encoded Unicode characters into human readable ones.