GCF::Log Class Reference

This class offers means to log a hierarchy of messages and process them. More...

#include <GCF3/Log>

Public Member Functions
void	setHandler (GCF::LogMessageHandlerInterface *handler)
GCF::LogMessageHandlerInterface *	handler () const
void	setLogFileName (const QString &logFileName)
QString	logFileName () const
void	setLogQtMessages (bool val)
bool	isLogQtMessages () const
void	fatal (const QString &context, const QString &message, const QString &details=QString())
void	fatal (const QString &context, const QByteArray &errorCode, const QString &message, const QString &details)
void	error (const QString &context, const QString &message, const QString &details=QString())
void	error (const QString &context, const QByteArray &errorCode, const QString &message, const QString &details)
void	warning (const QString &context, const QString &message, const QString &details=QString())
void	warning (const QString &context, const QByteArray &errorCode, const QString &message, const QString &details)
void	debug (const QString &context, const QString &message, const QString &details=QString())
void	debug (const QString &context, const QByteArray &errorCode, const QString &message, const QString &details)
void	info (const QString &context, const QString &message, const QString &details=QString())
void	info (const QString &context, const QByteArray &errorCode, const QString &message, const QString &details)
QList< GCF::LogMessage * >	logMessages () const
QString	toString () const
void	copyToClipboard ()
void	copyToSupport ()
void	handleLogMessage (GCF::LogMessage *msg)
void	print (GCF::LogMessage *msg, QTextStream &ts)
Public Member Functions inherited from GCF::LogMessageHandlerInterface
virtual void	toSupport (const QString &msg)
virtual void	toClipboard (const QString &msg)
virtual void	flush ()

Static Public Member Functions
static Log *	instance ()

Detailed Description

This is the only singleton class in all of GCF3. Through this single instance, users can log warning, debug, error and info messages. Although actual logging takes place via GCF::LogMessageHandlerInterface, set using setHandler() method; this class offers a simple API for feeding log messages and passing the buck to the handler when appropriate. By default an internal log-handler is registered as handler with GCF::Log; which dumps all log messages to a log file. You can enable logging of qDebug(), qWarning(), qFatal() and qCritical() messages by calling setLogQtMessages() method. Logging can be done from multiple threads as well. Forwarded calls to GCF::LogMessageHandlerInterface are serialized.

Usage:

void function()
{
    GCF::Log::instance()->info(GCF_DEFAULT_LOG_CONTEXT, "Simple log message");
}

The GCF_DEFAULT_LOG_CONTEXT constructs a default-context string based on the current function and line-number. Contexts help in figuring out where the log message has originated. You can use GCF_DEFAULT_LOG_CONTEXT or any other context string of your choice.

Each message dumped via info(), debug(), warning(), error(), and fatal() is stored as a GCF::LogMessage until the handler() handles the message. After the message is handled, it gets deleted.

Logs can be hierarchical. You can create a log-hierarchy by creating instances of the GCF::LogMessageBranch class. Branches are internally treated as log messages. Example:

void anotherFunction();
void yetAnotherFunction();

void function()
{
    GCF::LogMessageBranch branch("function() branch");
    ::anotherFunction();
    ::yetAnotherFunction();
}

void anotherFunction()
{
    GCF::Log::instance()->info(GCF_DEFAULT_LOG_CONTEXT, "Simple log message");
}

void yetAnotherFunction()
{
    GCF::Log::instance()->info(GCF_DEFAULT_LOG_CONTEXT, "Simple log message");
}

In the above example, log messages from anotherFunction() and yetAnotherFunction() are dumped into the log branch created within function(). When the log messages are dumped on to a log-file (or shown in a dialog box); the hierarchy is captured using indentation (or tree-view).

Hierarchichal logs are useful to understand the context in which a log message arose. For example, it might be useful to know whether the log message generated by yetAnotherFunction() happened in the context of a function() call or a direct call.

Note

Branches that have no log messages are automatically deleted.

Branches or messages, once dumped into the log file are automatically deleted.

See Also

GCF::LogMessage

Member Function Documentation

GCF::Log * GCF::Log::instance ( )

static

Returns

pointer to the only instance of this class in the application

void GCF::Log::setHandler

(

GCF::LogMessageHandlerInterface *

handler

)

Sets the handler to which all log messages are forwarded.

Parameters

handler

pointer to the handler. If null, the default internal handler is used.

GCF::LogMessageHandlerInterface * GCF::Log::handler

(

)

const

Returns

pointer to the handler used by the log

void GCF::Log::setLogFileName

(

const QString &

logFile

)

Sets the file-name into which all logs are dumped by the default handler.

Parameters

logFile

name of the file into which log messages are dumped by the default handler

QString GCF::Log::logFileName

(

)

const

Returns

complete path to the file into which log messages are dumped by the default handler.

void GCF::Log::setLogQtMessages

(

bool

val

)

This function can be used to enable/disable logging of qDebug(), qWarning(), qFatal() and qCritical() messages to the log. By default logging of QtDebug messages is disabled.

Parameters

val	true if QtDebug messages need to be logged, false otherwise.

bool GCF::Log::isLogQtMessages

(

)

const

Returns

true if QtDebug messages are logged. False otherwise.

See Also

setLogQtMessages()

void GCF::Log::fatal	(	const QString &	context,
		const QString &	message,
		const QString &	details = QString()
	)

Logs a fatal message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::fatal	(	const QString &	context,
		const QByteArray &	errorCode,
		const QString &	message,
		const QString &	details
	)

Logs a fatal message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
errorCode	a code associated with this message
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::error	(	const QString &	context,
		const QString &	message,
		const QString &	details = QString()
	)

Logs a error message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::error	(	const QString &	context,
		const QByteArray &	errorCode,
		const QString &	message,
		const QString &	details
	)

Logs a error message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
errorCode	a code associated with this message
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::warning	(	const QString &	context,
		const QString &	message,
		const QString &	details = QString()
	)

Logs a warning message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::warning	(	const QString &	context,
		const QByteArray &	errorCode,
		const QString &	message,
		const QString &	details
	)

Logs a warning message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
errorCode	a code associated with this message
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::debug	(	const QString &	context,
		const QString &	message,
		const QString &	details = QString()
	)

Logs a debug message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::debug	(	const QString &	context,
		const QByteArray &	errorCode,
		const QString &	message,
		const QString &	details
	)

Logs a warning message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
errorCode	a code associated with this message
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::info	(	const QString &	context,
		const QString &	message,
		const QString &	details = QString()
	)

Logs a information message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

void GCF::Log::info	(	const QString &	context,
		const QByteArray &	errorCode,
		const QString &	message,
		const QString &	details
	)

Logs a information message into the current branch

Parameters

context	a string representing the context of the message. Use of GCF_DEFAULT_LOG_CONTEXT for this parameter is recommended
errorCode	a code associated with this message
message	a brief one liner associated with this message
details	a detailed multi-line text associated with this message

QList< GCF::LogMessage * > GCF::Log::logMessages

(

)

const

Returns

list of top-level log messages and branches.

QString GCF::Log::toString

(

)

const

Returns

a string representation of the log

void GCF::Log::copyToClipboard

(

)

Requests the handler to copy the string representation of this log to the clipboard.

Note

Actual copy of log-messages to clipboard happens only if the handler supports it.

void GCF::Log::copyToSupport

(

)

Requests the handler to submit the string representation of this log support (via email or otherwise).

Note

Actual submit of log-messages to support happens only if the handler supports it.

void GCF::Log::handleLogMessage ( GCF::LogMessage *  msg )

virtual

GCF::Log would call this function of the handler with the reported message so that the handler can log it appropriately.

Implements GCF::LogMessageHandlerInterface.

void GCF::Log::print ( GCF::LogMessage *  msg, QTextStream &  ts  )

virtual

GCF::Log would call this function of the handler with the reported message so that the handler can stream the log in appropriate print format to the text stream passed.

Implements GCF::LogMessageHandlerInterface.