delphi neon

Neon – JSON Serialization Library for Delphi

What is Neon

Neon is a serialization library for Delphi that helps you to convert (back and forth) objects and other values to JSON. It supports simple Delphi types but also complex class and records. Neon has been designed with REST in mind, to exchange pure data between applications with no \”metadata\” or added fields, in fact Neon is the default JSON serialization engine for the WiRL REST Library.

Please take a look at the Demos to see Neon in action.

Neon Main Demo

This is the main demo where you can see how you can serialize/deserialize simple types, records, classes, Delphi specific types (TStringList, TDataSet, etc…):

Neon Benchmarks Demo

This new demo tries to compare the standard TJSON serialization engine with the TNeon engine, with a few changes you can compare TNeon with other serialization engines out there:

A Neon Introduction by Holger Flick (Video)

General Features

Configuration

Extensive configuration through INeonConfiguration interface:

• Word case (Unchanged, UPPERCASE, lowercase, PascalCase, camelCase, snake_case)
• CuStOM CAse (through anonymous method)
• Member types (Fields, Properties)
• Option to ignore the \”F\” if you choose to serialize the fields
• Member visibility (private, protected, public, published)
• Custom serializer registration
• Use UTC date in serialization
• Auto creation of nil (object) members

Delphi Types Support

Neon supports the (de)serialization of most Delphi standard types, records, array and of course classes. Classes can be complex as you want them to be, can contain array, (generic) lists, sub-classes, record, etc…

Simple values

• Basic types: string, Integer, Double, Boolean, TDateTime

Complex values

• Dynamic Arrays of (basic types, records, classes, etc…)
• Records with fields of (basic types, records, classes, arrays, etc…)
• Classes with fields of (basic types, records, classes, arrays, etc…)
• Generic lists
• Dictionaries (key must be of type string)
• Streamable classes

Custom Serializers

• Inherit from TCustomSerializer and register the new serializer class in the configuration

Todo

Code

• More Unit Tests

Prerequisite

This library has been tested with Delphi 12 Athens, Delphi 11 Alexandria, Delphi 10.4 Sydney, Delphi 10.3 Rio, Delphi 10.2 Tokyo, but with a minimum amount of work it should compile with Delphi XE7 and higher

Libraries/Units dependencies

This library has no dependencies on external libraries/units.

Delphi units used:

• System.JSON (DXE6+)
• System.Rtti (D2010+)
• System.Generics.Collections (D2009+)

Installation

Simply add the source path \”Source\” to your Delphi project path and.. you are good to go!

Code Examples

Serialize an object

Using TNeon utility class

The easiest way to serialize and deserialize is to use the TNeon utility class:

Object serialization:

var
  LJSON: TJSONValue;
begin
  LJSON := TNeon.ObjectToJSON(AObject);
  try
    Memo1.Lines.Text := TNeon.Print(LJSON, True);
  finally
    LJSON.Free;
  end;
end;

Object deserialization:

var
  LJSON: TJSONValue;
begin
  LJSON := TJSONObject.ParseJSONValue(Memo1.Lines.Text);
  try
    TNeon.JSONToObject(AObject, LJSON, AConfig);
  finally
    LJSON.Free;
  end;

Using TNeonSerializer and TNeonDeserializer classes

Using the TNeonSerializerJSON and TNeonDeserializerJSON classes you have more control over the process.

Object serialization:

var
  LJSON: TJSONValue;
  LWriter: TNeonSerializerJSON;
begin
  LWriter := TNeonSerializerJSON.Create(AConfig);
  try
    LJSON := LWriter.ObjectToJSON(AObject);
    try
      Memo1.Lines.Text := TNeon.Print(LJSON, True);
      MemoError.Lines.AddStrings(LWriter.Errors);
    finally
      LJSON.Free;
    end;
  finally
    LWriter.Free;
  end;
end;

Object deserialization:

var
  LJSON: TJSONValue;
  LReader: TNeonDeserializerJSON;
begin
  LJSON := TJSONObject.ParseJSONValue(Memo1.Lines.Text);
  if not Assigned(LJSON) then
    raise Exception.Create(\'Error parsing JSON string\');

  try
    LReader := TNeonDeserializerJSON.Create(AConfig);
    try
      LReader.JSONToObject(AObject, LJSON);
      MemoError.Lines.AddStrings(LWriter.Errors);
    finally
      LReader.Free;
    end;
  finally
    LJSON.Free;
  end;

Neon configuration

It\’s very easy to configure Neon,

var
  LConfig: INeonConfiguration;
begin
  LConfig := TNeonConfiguration.Default
    .SetMemberCase(TNeonCase.SnakeCase)     // Case settings
    .SetMembers(TNeonMembers.Properties)    // Member type settings
    .SetIgnoreFieldPrefix(True)             // F Prefix settings
    .SetVisibility([mvPublic, mvPublished]) // Visibility settings

    // Custom serializer registration
    .GetSerializers.RegisterSerializer(TGUIDSerializer)
  ;
end;

Paolo Rossi