COM API

NLog features a COM Interop API tha can be used to provide logging for legacy COM applications/components that are deployed as part of a .NET solution. COM support is available with 2 coclasses with ProgIDs: NLog.LogManager which lets you perform basic configuration and NLog.Logger which does the actual logging.

COM components are supported for many languages, both scripting and compiled. Basic usage is similar to the .NET API, with the following exceptions:

• Instances of loggers are created directly, you don't need to use LogManager to get them.
• Because COM classes don't support passing parameters at construction time, you need to set each logger's name by setting its LoggerName
• Passing of format arguments isn't supported
• Logger levels (arguments to the Log() method) are passed as strings instead of enumeration values - this provides maximum compatibility with scripting environments.

The following example demonstrates the use of NLog COM api for JScript.

var logmanager = new ActiveXObject("NLog.LogManager"); 
WScript.Echo("Loading config from file 'config8.nlog'..."); 
logmanager.InternalLogToConsole = true; 
logmanager.InternalLogFile = "internal_log.txt"; 
logmanager.InternalLogLevel = "Info"; 
logmanager.LoadConfigFromFile("config8.nlog"); 
 
var logger = new ActiveXObject("NLog.Logger"); 
logger.LoggerName = "TestLogger"; 
logger.Log("Trace", "This is a trace message"); 
logger.Log("Debug", "This is a debugging message"); 
logger.Log("Info", "This is an information message"); 
logger.Log("Warn", "This is a warning message"); 
logger.Log("Error", "This is an error"); 
logger.Log("Fatal", "This is a fatal message"); 
 
logger.Trace("This is a trace message"); 
logger.Debug("This is a debugging message"); 
logger.Info("This is an information message"); 
logger.Warn("This is a warning message"); 
logger.Error("This is an error"); 
logger.Fatal("This is a fatal message"); 
 
WScript.Echo("Loading config from file 'config8a.nlog'..."); 
logmanager.InternalLogToConsole = false; 
logmanager.InternalLogFile = "internal_log.txt"; 
logmanager.InternalLogLevel = "Fatal"; 
logmanager.LoadConfigFromFile("config8a.nlog"); 
 
logger.Log("Trace", "This is a trace message"); 
logger.Log("Debug", "This is a debugging message"); 
logger.Log("Info", "This is an information message"); 
logger.Log("Warn", "This is a warning message"); 
logger.Log("Error", "This is an error"); 
logger.Log("Fatal", "This is a fatal message"); 
 
logger.Trace("This is a trace message"); 
logger.Debug("This is a debugging message"); 
logger.Info("This is an information message"); 
logger.Warn("This is a warning message"); 
logger.Error("This is an error"); 
logger.Fatal("This is a fatal message");

Last updated: 2006-07-10 11:32:55