Delphi login and JSON conversion to dataset for Dreamfactory

gistfile1.txt

private
    { Private declarations }
    JSONLogin: TJSONObject;
    JSONResponse1, JSONResponse2: TJSONObject;
    sCleanedSessionID, sCleanedSessionToken: string;
    procedure login(sEmail, sPassword: string);
    procedure GetDataFromTable(sTableName: string);
  public
    { Public declarations }
  end;

const
  //Get these from DreamFactory
  BASEURL = 'http://localhost:82/api/v2';
  APIKEY = 'd52c15307c1e4bd7270cdd53fa416bee3d201972231b737ea69eec888889a8b2';

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  Login(edit1.Text, edit2.Text);  //For the user name and password
end;

procedure TForm1.GetDataFromTable(sTableName: string);
begin
  //The DreamFactory Service is MSSQL; the table is Tasks
  with RESTRequest2 do
  begin
    Accept := 'application/json';
    Resource := 'MSSQL/_table/tasks';
    Params.AddItem('X-DreamFactory-API-Key', APIKEY, pkHTTPHEADER);
    Params.AddItem('X-DreamFactory-Session-Token', sCleanedSessionToken, pkHTTPHEADER);
    Execute;
  end;
end;

procedure TForm1.JSONToDatasetTasks(JSON: TJSONObject);
var
  aTasks: TJSONArray;
  oTask: TJSONObject;
  vItem: TJSONValue;
  i: integer;
begin
  try
    //Put the JSON object into an array
    aTasks := JSON.Get('resource').JsonValue as TJSONArray;
    if aTasks = nil then
      ShowMessage('Empty task list') else
    begin
    dxMemdata1.active := true;  //dxMemdata is an in-memory table from Developer Express.  I previously added the columns
    //Loop through the individual records
    for i := 0 to aTasks.size -1 do
    begin
      oTask := TJSONObject(aTasks.Get(i));
      vItem := oTask.Get('Description').JSONValue;
      With dxMemdata1 do
      begin
        insert;
        Fieldvalues['Description'] := vItem.Value;
      end;
      //Do something similar for the remaining columns
    end;
  end;
  finally
    JSON.Free;
  end;

end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  GetDataFromTable('tasks');
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  JSONToDatasetTasks(JSONResponse2);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  RestClient1.BaseURL := BASEURL;
end;

procedure TForm1.RESTRequest1AfterExecute(Sender: TCustomRESTRequest);
var
  jvSessionID, jvSessionToken: TJSONValue;
  sSessionID, sSessionToken: string;
begin
  JSONLogin.Free;
  //RESTResponse1 gets the response from RestRequest1; it is linked in the Response property of the request
  JSONResponse1 := nil;
  //Convert the response into a JSON object for parsing
  JSONResponse1 := TJSONObject.ParseJSONValue(TEncoding.ASCII.GetBytes(RESTResponse1.JSONText), 0) as TJSONObject;
  //Get the session id and token as JSONValues (they appear to be identical)
  jvSessionID := JSONResponse1.GetValue('session_id');
  jvSessionToken := JSONResponse1.GetValue('session_token');
  //Convert it to a string
  sSessionID := jvSessionID.ToString;
  //Remove the opening and closing double quotes
  sCleanedSessionID := StringReplace(sSessionID,'"','',[rfReplaceAll]);
  sSessionToken := jvSessionToken.ToString;
  sCleanedSessionToken := StringReplace(sSessionToken,'"','',[rfReplaceAll]);
  JSONResponse1.Free;
end;

procedure TForm1.RESTRequest2AfterExecute(Sender: TCustomRESTRequest);
begin
  Label6.caption :=  RESTResponse2.JSONText;
  JSONResponse2 := TJSONObject.ParseJSONValue(TEncoding.ASCII.GetBytes(RESTResponse2.JSONText), 0) as TJSONObject;
  //JSONResponse2.Free;  //This is done by JSONToDatasetTasks
end;

procedure TForm1.login(sEmail, sPassword: string);
begin
  with RestRequest1 do
  begin
    Method := rmPost;
    Resource := 'user/session';
    Accept := 'application/json';  //Important: the default values in the Delphi RestRequest component don't work
  end;
  JSONLogin := TJSONObject.Create;
  with JSONLogin do
  begin
    AddPair('email', sEmail);
    AddPair('password', sPassWord);
  end;
  with RestRequest1 do
  begin
    AddBody(JSONLogin);
    Execute;
  end;
end;

end