Send JSON over TCP connection

[TiGü]

Please be aware, in this way you serialize the internal structure of the TDepartmentList.

Code:

'{"ownsObjects":true,"listHelper":[2],"items":[{"deptName":"Finance","deptID":10},{"deptName":"HUMAN RESOURCE","deptID":11}]}'

Solution:

Delphi-Quellcode:

program Project1;

{$APPTYPE CONSOLE}
{$R *.res}

uses
    System.SysUtils,
    System.Generics.Collections,
    REST.Json;

type
    TDepartmentsInfo = Packed Record
        Packet_ID: Integer;
        DeptInfo: TArray<Char>; // This will hold the JSON converted class
        function BuffSize: Integer;
    end;

    PDepartmentsInfo = ^TDepartmentsInfo;

type
    TDepartment = class
    strict private
        FDeptName: string;
        FDeptID: Integer;
    public
        property DeptName: string read FDeptName write FDeptName;
        property DeptID: Integer read FDeptID write FDeptID;
    end;

    TDepartmentList = class(TObjectList<TDepartment>);

function TDepartmentsInfo.BuffSize: Integer;
begin
    Result := SizeOf(Packet_ID) + (SizeOf(Char) * Length(DeptInfo));
end;

procedure SocketSendDeptInfo(const DepartmentsInfo: PDepartmentsInfo; BufferSize: Integer);
begin

end;

Procedure SerializeAndSend();
var
    DepartmentList: TDepartmentList;
    Department: TDepartment;
    Json: string;
    DepartmentsInfo: TDepartmentsInfo;
begin
    DepartmentList := TDepartmentList.Create();
    try
        Department := TDepartment.Create();
        Department.DeptName := 'Finance';
        Department.DeptID := 10;
        DepartmentList.Add(Department);

        Department := TDepartment.Create();
        Department.DeptName := 'HUMAN RESOURCE';
        Department.DeptID := 11;
        DepartmentList.Add(Department);

        Json := TJson.ObjectToJsonString(DepartmentList);
        DepartmentsInfo.Packet_ID := 1;

        DepartmentsInfo.DeptInfo := Json.ToCharArray;

        SocketSendDeptInfo(@DepartmentsInfo, DepartmentsInfo.BuffSize);
    finally
        DepartmentList.Free();
    end;

end;

begin
  SerializeAndSend;
end.

[mandoza]

Zitat von TiGü:

Please be aware, in this way you serialize the internal structure of the TDepartmentList.

Code:

'{"ownsObjects":true,"listHelper":[2],"items":[{"deptName":"Finance","deptID":10},{"deptName":"HUMAN RESOURCE","deptID":11}]}'

Is there any issue with that ( network latency ... etc ) ?
Please any other better way .

[Sherlock]

Hi mandoza, I would like to remind you, that we have a fine english speaking sibling to this forum found here: en.delphipraxis.net.

Sherlock

[TiGü]

Zitat von mandoza:

Is there any issue with that ( network latency ... etc ) ?
Please any other better way .

It's unnessacry overhead and can't properly parsed in other dev environments.
Imagine if someone with Javascript, C++ or something else want to parse your JSON with ownObjects and listHelper.

You can workaround this with a simple data transfer object (DTO).

Code:

'{"items":[{"deptName":"Finance","deptID":10},{"deptName":"HUMAN RESOURCE","deptID":11}]}'

Delphi-Quellcode:

program Project1;

{$APPTYPE CONSOLE}
{$R *.res}

uses
    Department in 'Department.pas',
    System.SysUtils,
    REST.Json;

Procedure SerializeAndSend;
var
    DepartmentList, DepartmentList2: TDepartmentList;
    Department: TDepartment;
    Json: string;
    DepartmentsInfo: TDepartmentsInfo;
    DepartmentStore: TDepartmentStore;
begin
    DepartmentList := TDepartmentList.Create;
    try
        Department := TDepartment.Create;
        Department.DeptName := 'Finance';
        Department.DeptID := 10;
        DepartmentList.Add(Department);

        Department := TDepartment.Create;
        Department.DeptName := 'HUMAN RESOURCE';
        Department.DeptID := 11;
        DepartmentList.Add(Department);

        DepartmentStore := TDepartmentStore.Create(DepartmentList.ToArray);
        try
            Json := TJson.ObjectToJsonString(DepartmentStore);
        finally
            DepartmentStore.Free;
        end;

    finally
        DepartmentList.Free();
    end;

    DepartmentsInfo.Packet_ID := 1;
    DepartmentsInfo.DeptInfo := Json.ToCharArray;
    SocketSendDeptInfo(@DepartmentsInfo, DepartmentsInfo.BuffSize);

    // Deserialization
    DepartmentStore := TJson.JsonToObject<TDepartmentStore>(Json);
    DepartmentList2 := TDepartmentList.Create();
    try
        DepartmentList2.AddRange(DepartmentStore.Items);
    finally
        DepartmentList2.Free;
    end;
end;

begin
    SerializeAndSend;
    Readln;

end.

Delphi-Quellcode:

unit Department;

interface

uses
    System.SysUtils,
    System.Generics.Collections,
    REST.Json,
    System.Rtti;

type
    TDepartmentsInfo = Packed Record
        Packet_ID: Integer;
        DeptInfo: TArray<Char>; // This will hold the JSON converted class
        function BuffSize: Integer;
    end;

    PDepartmentsInfo = ^TDepartmentsInfo;

type
    TDepartment = class
    strict private
        FDeptName: string;
        FDeptID: Integer;
    public
        property DeptName: string read FDeptName write FDeptName;
        property DeptID: Integer read FDeptID write FDeptID;
    end;

    TDepartmentList = class(TObjectList<TDepartment>);

    TDepartmentStore = class
    private
        FItems: TArray<TDepartment>;
    public
        constructor Create(const AItems: TArray<TDepartment>);
        property Items: TArray<TDepartment> read FItems;
    end;

procedure SocketSendDeptInfo(const DepartmentsInfo: PDepartmentsInfo;
  BufferSize: Integer);

implementation

function TDepartmentsInfo.BuffSize: Integer;
begin
    Result := SizeOf(Packet_ID) + (SizeOf(Char) * Length(DeptInfo));
end;

procedure SocketSendDeptInfo(const DepartmentsInfo: PDepartmentsInfo;
  BufferSize: Integer);
begin

end;

constructor TDepartmentStore.Create(const AItems: TArray<TDepartment>);
begin
    FItems := AItems;
end;

end.

[Schokohase]

Talking about overhead ... why not remove all overhead?

Code:

[
  {
    "deptName": "Finance",
    "deptID": 10
  },
  {
    "deptName": "HUMAN RESOURCE",
    "deptID": 11
  }
]

contains the same information as

Code:

{
  "items": [
    {
      "deptName": "Finance",
      "deptID": 10
    },
    {
      "deptName": "HUMAN RESOURCE",
      "deptID": 11
    }
  ]
}

but with less chars (overhead).