Simple Logging Utilily in ATL

You must have noticed that many there are many occassions
while developing an ATL component ,when you feel that you should
trace some messages at some point.For such purpose,first thing
which almost every one tries is ATLTRACE or ATLTRACE2 both of
which Trace the messages on debug output,That is perfect.But
problem is that you can trace only while you are in debug
mode.You cannot trace anything while you are running the
application.One option is to look for NT Event logger(if you are
using WIndows NT)But the problem is there are so many different
events there that you feel like giving up.Moreever you need to
learn the APIs used to write anything to NT Event Loggger .So I
thought of developing a simple ATL component which you can use to
log events.Remember this is just the first version.Based on the
input I am planning to enhance the logger and make some more
functions available like Saving of log to a database or
file.Sorting by time etc.

Following is the description about the source code given here

When you extract this zip file you will get three
directories.For example if you extract the zip file into c:\code,
you will get c:\Code\ATLLogApp. This is the
Log server. i.e it is responsible for logging events.If you want
you can straightaway compile this dll and then use it in you
application.This dll hosts one component CoLogger which exposes
ICoLogger interface .It has following methods:

Initialize(); This should be called to
initialize the server.
Log([in] BSTR Message);Call this method to log
the data.
UnInitialize(); This uninitializes the server.

This is sample ATL client for the server which just forwards
calls from MFC Client

c:\Code\MFCClient: This is an
MFC CLient which logs messages after every second.There
is a timer which fires events .

How to use.

In you application(MFC or ATL) just type the following

#import "..\ATLLogApp.tlb" no_namespace named_guids // specify the path to the tlb

You will then get two files .tlh and .tli in your source output
directory (by default, this will be the debug directory). Now to use it just declare a smart
pointer of type ICoLoggerPtr as in this example.

CYourclass:public ...
 ICoLoggerPtr m_Log;

in the cpp file create the instance of the logger and then call Initialize.

// implemention file
const HRESULT hrCreate = m_Log.CreateInstance(__uuidof(CoLogger));
if (FAILED(hrCreate)) return E_FAIL;
const HRESULT hrInit = m_Log->Initialize();

Now call the Log method on this interface wherever you want to.

Here is a sample screen short when you run the application.

Press Atl-S.You get this screen after some time.

Any suggestions are welcome.

Compilation Order

  • AtlLogApp
  • AtlClientForTracer
  • MFCClient
  • Downloads

    Download source – 48 Kb

    More by Author

    Must Read