Logging from RAD Server

[corneliusdavid 214]

I'm fairly new to RAD Server and while I have a small module working, pulling data from a database, I'd like to be able to do some logging. Sure, I can create another endpoint and dump stuff in a JSON result, but that's not really behind-the-scenes logging. And yes, I could create a log table and insert records in there.

 

But there's an intriguing class in the EMS namespace called TEMSLoggingService. I can't find any documentation or examples that explain what this is for or how to use it.

 

Anyone have any wisdom on this to share?

[Lars Fosdal 1792]

There is documentation, but it is meagre on examples of use.
http://docwiki.embarcadero.com/Libraries/Sydney/en/EMS.Services.TEMSLoggingService

[corneliusdavid 214]

I looked in DocWiki but could not find it. This is a start, albeit not much more than viewing the source.

 

Thanks for the link!

[mvanrijnen 123]

unit MyUnit;

interface

{$IFDEF RADSERVER_PACKAGE}
uses .....
     EMS.ResourceAPI;

type
  THSLoggerRADServerDebugTargetQueue = class(THSLoggerBaseTargetQueue)
  protected
    function HandleTargetItem(const AItem: THSLLoggerItem): Boolean; override;
  public
  end;
{$ENDIF}

implementation

{$IFDEF RADSERVER_PACKAGE}

{ THSLoggerRADServerDebugTargetQueue }

function THSLoggerRADServerDebugTargetQueue.HandleTargetItem(const AItem: THSLLoggerItem): Boolean;
var
  line: string;
begin
  inherited;
  .....
    TEMSEndpointEnvironment.Instance.LogMessage(line);
  ....
end;

{$ENDIF}

end.

 

Edited August 20, 2021 by mvanrijnen
added code

[mvanrijnen 123]

Somehow inserting code goes wrong sometime, my text of my post disappeared.

You just need the EMS.ResourceAPI in your uses and then you can use the TEMSEndPointEnvironment.Instance.LogMessage('your log text');

 

In debugmode (running your RADServer package from the IDE), the logging goes into the radserver console window, where the radserver itself also logs. 

We are not in production yet, so i do not know at the moment where the logging goes in a production environment 🙂

 

 

I use this in a logging framework, which also can log to file, database etc etc.

 

 

Did not see the TEMSLoggingService before, have to inspect that, maybe it's the better way to work.

 

 

[edit, added first code for the emsloggingservice)

so, first tryout for the loggingservice:

 

unit .......;

interface

uses .....
     EMS.Services;

type
  THSLoggerRADServerDebugTargetQueue = class(THSLoggerBaseTargetQueue)
  private
    femslogsvc : IEMSLoggingService;
  protected
    function HandleTargetItem(const AItem: THSLLoggerItem): Boolean; override;
  public
    procedure DoBeforeStart; override;
    procedure DoAfterStop; override;

    {TODO -oOwner -cGeneral : CheckCanStart wordt helemaal niet aangeroepen ???? }
    procedure CheckCanStart(var ACanStart: Boolean; var AMessage: string); override;
  end;

implementation

uses .....,
     EMS.ResourceAPI;

{ THSLoggerRADServerDebugTargetQueue }

procedure THSLoggerRADServerDebugTargetQueue.CheckCanStart(var ACanStart: Boolean; var AMessage: string);
begin
  inherited;
  ACanStart := True;
end;

procedure THSLoggerRADServerDebugTargetQueue.DoAfterStop;
begin
  femslogsvc := nil;
  inherited;
end;

procedure THSLoggerRADServerDebugTargetQueue.DoBeforeStart;
begin
  femslogsvc := nil;
  inherited;

  if TEMSServices.TryGetService<IEMSLoggingService>(femslogsvc) then
  begin
    if not femslogsvc.LoggingEnabled then
    begin
      femslogsvc := nil;
    end;
  end;
end;

function THSLoggerRADServerDebugTargetQueue.HandleTargetItem(const AItem: THSLLoggerItem): Boolean;
var
 obj : TJSONObject;
begin
  inherited;
  Result := False;
  try
    if Assigned(femslogsvc) then
    begin
      obj := TJSONObject.Create();
      obj.AddPair('user', AItem.UserName);
      obj.AddPair('computer', AItem.ComputerName);
      obj.AddPair('datetime', DateToISO8601(AItem.DateTime));
      obj.AddPair('message', AItem.LogMessage);
      obj.AddPair('position', AItem.Position);
      femslogsvc.Log(AItem.LogType.AsString, obj);
    end;
    Result := True;
  except
    on e: exception do
    begin
      // DebugLog('xx', 'xxxx');
    end;
  end;
end;

end.

 

Edited August 20, 2021 by mvanrijnen

[corneliusdavid 214]

3 hours ago, mvanrijnen said:

TEMSEndpointEnvironment.Instance.LogMessage(line);

This is perfect--exactly what I was looking for!  Thank you!

 

I'll have to spend some time checking out your THSLoggerRADServerDebugTargetQueue class. That looks like it could useful as well.

 

Thanks again!