Horse middleware

Horse.JsonFlow (unit Horse.JsonFlow) integrates JsonFlow with the Horse web framework. It provides automatic JSON body parsing for POST / PUT / PATCH requests and adds a typed Body<T> helper on THorseRequest.

Registration

uses
  Horse,
  Horse.JsonFlow;

begin
  THorse.Use(HorseJsonFlow);   // default charset: UTF-8, en-US format
  // or
  THorse.Use(HorseJsonFlow('UTF-8'));

  THorse.Post('/users',
    procedure(Req: THorseRequest; Res: THorseResponse; Next: TNextProc)
    var
      LUser: TUser;
    begin
      LUser := Req.Body<TUser>;
      try
        // LUser is populated from the JSON request body
        Res.Send('Created: ' + LUser.Name);
      finally
        LUser.Free;
      end;
    end
  );

  THorse.Listen(9000);
end.

What the middleware does

1. Checks if the request method is POST, PUT, or PATCH.
2. Reads the raw body string from THorseRequest.
3. Uses TJsonFlow.JsonToObject<T> to deserialize the body into the requested type T.
4. The THorseRequestHelper.Body<T> method returns the typed object.

Format settings

Calling HorseJsonFlow (no charset argument) also sets TJsonFlow.FormatSettings to en-US locale — ensuring decimal separator is . for all JSON operations in the application.

Global TJsonFlow.FormatSettings

uses
  JsonFlow;
  SysUtils;

var
  LFS: TFormatSettings;
begin
  LFS := TFormatSettings.Create('en-US');
  TJsonFlow.FormatSettings := LFS;
end;

This affects the shared writer/reader/builder used by the TJsonFlow facade.

warning

THorseRequestHelper.Body<T> returns a new object — the caller is responsible for freeing it. In Horse handlers the convention is to free after the response is sent (or use a try/finally).

Horse installation

boss install HashLoad/horse

Horse.JsonFlow adds Source\Middleware-Horse\ to the search path. Make sure both JsonFlow and Horse search paths are included in your .dproj.