How to convert an object to JSON and back with a single line of code

Ever wanted to take an Object into a format that is easily persisted and back? Well now you can. New in XE6 is the REST.JSON unit. This allows you access to TJSON a class with some very helpful class methods. Using TJSON you can convert an object to a JSON string and back with a little help from generics along the way.

The following code uses a class called TFoo that has a Foo and a Fee property (string and Integer) Using TJson you can then see how to covert the object to a string and back ready for storage, transport etc.

uses REST.JSON; // Also new System.JSON

procedure TForm1.Button1Click(Sender: TObject);

var

  Foo: TFoo;

begin

  Foo := TFoo.Create;

  try

    Foo.Foo := 'Hello World';

    Foo.Fee := 42;

    Memo1.Lines.Text := TJson.ObjectToJsonString(Foo);

  finally

    Foo.Free;

  end;

  Foo := TJson.JsonToObject<TFoo>(Memo1.Lines.Text);

  try

    Foo.Fee := 100;

    Memo1.Lines.Add(TJson.ObjectToJsonString(Foo));

  finally

    Foo.Free;

  end;

end;

If you want to watch this being demo’ed this very show video shows it in action http://youtu.be/TSqWoFvjj5g