Serialization currently only works on public fields. However, the long-term plan is to use properties too and give configuration options. Field names are case sensitive. Take the following class as an example:

TPerson = class(TObject)
public 
  (* Field names match the JSON field names, including case *)
  id: Integer;
  [JsonName('personeName')] // it is optional
  name: String;
  email: String;

  (* Static constructor *)
  class function NewFrom(Id: Integer; Name, EMail: String): TPerson;
end;

Would map to the following JSON:

{
  "id": 12345,
  "personeName": "David Example",
  "email": "[email protected]"
}

Now serialization is available for delphi 2009 and older, using old RTTI(Run-time Type Information). This serialization mode is much more restricted, due to own limitations of existing RTTI in previous versions of Delphi.

There are some prerequisites for the class definition:

• Are only accepted properties
• The properties must be defined in the published section
• The class should enable compiler directives to include type information at run-time.This can be done inheriting of TPersistent class, or declaring the class manually between compiler directives {$M } and {$M-}.

See the example below:

• Inheriting TPersistent

   TPerson = class(TPersistent)
   private
   //omitted fields
   published
     property id: Integer read FId write FId;
     property name: String read FName write FName;
     property email: String read FEmail write FEmail;
   end;
  

• Using compiler directives(no need to use inheritance)

   {$M } or {$TYPEINFO ON}
   TPerson = class 
   private
   //omitted fields
   published
     property id: Integer read FId write FId;
     property name: String read FName write FName;
     property email: String read FEmail write FEmail;
   end;
   {$M-} or {$TYPEINFO OFF}