Log

Log class defines the interface for the log targets used by wxWidgets logging functions as explained in the Log Classes Overview.

The only situations when you need to directly use this class is when you want to derive your own log target because the existing ones don’t satisfy your needs.

Otherwise, it is completely hidden behind the LogXXX and you may not even know about its existence.

Note

For console-mode applications, the default target is LogStderr, so that all LogXXX() functions print on stderr when USE_GUI = 0.

See also

Log Classes Overview, LogXXX

Inheritance Diagram

Inheritance diagram for class Log

Known Subclasses

LogBuffer, LogChain, LogGui, LogStderr, LogStream, LogTextCtrl

Methods Summary

AddTraceMask	Add the mask to the list of allowed masks for LogTrace.
ClearTraceMasks	Removes all trace masks previously set with AddTraceMask .
DisableTimestamp	Disables time stamping of the log messages.
DoLogRecord	Called to log a new record.
DoLogText	Called to log the specified string.
DoLogTextAtLevel	Called to log the specified string at given level.
DontCreateOnDemand	Instructs Log to not create new log targets on the fly if there is none currently (see GetActiveTarget ).
EnableLogging	Globally enable or disable logging.
Flush	Some of Log implementations, most notably the standard LogGui class, buffer the messages (for example, to avoid showing the user a zillion of modal message boxes one after another – which would be really annoying).
FlushActive	Flushes the current log target if any, does nothing if there is none.
GetActiveTarget	Returns the pointer to the active log target (may be None).
GetLogLevel	Returns the current log level limit.
GetRepetitionCounting	Returns whether the repetition counting mode is enabled.
GetTimestamp	Returns the current timestamp format string.
GetTraceMasks	Returns the currently allowed list of string trace masks.
GetVerbose	Returns whether the verbose mode is currently active.
IsAllowedTraceMask	Returns True if the mask is one of allowed masks for LogTrace.
IsEnabled	Returns True if logging is enabled at all now.
IsLevelEnabled	Returns True if logging at this level is enabled for the current thread.
LogRecord	Log the given record.
RemoveTraceMask	Remove the mask from the list of allowed masks for LogTrace.
Resume	Resumes logging previously suspended by a call to Suspend .
SetActiveTarget	Sets the specified log target as the active one.
SetComponentLevel	Sets the log level for the given component.
SetFormatter	Sets the specified formatter as the active one.
SetLogLevel	Specifies that log messages with level greater (numerically) than logLevel should be ignored and not sent to the active log target.
SetRepetitionCounting	Enables logging mode in which a log message is logged once, and in case exactly the same message successively repeats one or more times, only the number of repetitions is logged.
SetThreadActiveTarget	Sets a thread-specific log target.
SetTimestamp	Sets the timestamp format prepended by the default log targets to all messages.
SetVerbose	Activates or deactivates verbose mode in which the verbose messages are logged as the normal ones instead of being silently dropped.
Suspend	Suspends the logging until Resume is called.

Class API

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class Log(object)

Log class defines the interface for the log targets used by wxWidgets logging functions as explained in the Log Classes Overview.

Methods

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static AddTraceMask(mask)

Add the mask to the list of allowed masks for LogTrace.

Parameters:mask (string) –

See also

RemoveTraceMask , GetTraceMasks

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static ClearTraceMasks()

Removes all trace masks previously set with AddTraceMask .

See also

RemoveTraceMask

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static DisableTimestamp()

Disables time stamping of the log messages.

Notice that the current time stamp is only used by the default log formatter and custom formatters may ignore calls to this function.

New in version 2.9.0.

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DoLogRecord(self, level, msg, info)

Called to log a new record.

Any log message created by LogXXX() functions is passed to this method of the active log target. The default implementation prepends the timestamp and, for some log levels (e.g. error and warning), the corresponding prefix to msg and passes it to DoLogTextAtLevel .

You may override this method to implement custom formatting of the log messages or to implement custom filtering of log messages (e.g. you could discard all log messages coming from the given source file).

Parameters:

• level (LogLevel) –
• msg (string) –
• info (LogRecordInfo) –

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DoLogText(self, msg)

Called to log the specified string.

A simple implementation might just send the string to stdout or stderr or save it in a file (of course, the already existing LogStderr can be used for this).

The base class version of this function asserts so it must be overridden if you don’t override DoLogRecord or DoLogTextAtLevel .

Parameters:msg (string) –

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DoLogTextAtLevel(self, level, msg)

Called to log the specified string at given level.

The base class versions logs debug and trace messages on the system default debug output channel and passes all the other messages to DoLogText .

Parameters:

• level (LogLevel) –
• msg (string) –

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static DontCreateOnDemand()

Instructs Log to not create new log targets on the fly if there is none currently (see GetActiveTarget ).

(Almost) for internal use only: it is supposed to be called by the application shutdown code (where you don’t want the log target to be automatically created anymore).

Note that this function also calls ClearTraceMasks .

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static EnableLogging(enable=True)

Globally enable or disable logging.

Calling this function with False argument disables all log messages for the current thread.

Parameters:enable (bool) – Return type:bool Returns:The old state, i.e. True if logging was previously enabled and False if it was disabled.

See also

LogNull, IsEnabled

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Flush(self)

Some of Log implementations, most notably the standard LogGui class, buffer the messages (for example, to avoid showing the user a zillion of modal message boxes one after another – which would be really annoying).

This function shows them all and clears the buffer contents. If the buffer is already empty, nothing happens.

If you override this method in a derived class, call the base class version first, before doing anything else.

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static FlushActive()

Flushes the current log target if any, does nothing if there is none.

When this method is called from the main thread context, it also flushes any previously buffered messages logged by the other threads. When it is called from the other threads it simply calls Flush on the currently active log target, so it mostly makes sense to do this if a thread has its own logger set with SetThreadActiveTarget .

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static GetActiveTarget()

Returns the pointer to the active log target (may be None).

Notice that if SetActiveTarget hadn’t been previously explicitly called, this function will by default try to create a log target by calling AppTraits.CreateLogTarget which may be overridden in a user-defined traits class to change the default behaviour. You may also call DontCreateOnDemand to disable this behaviour.

When this function is called from threads other than main one, auto-creation doesn’t happen. But if the thread has a thread-specific log target previously set by SetThreadActiveTarget , it is returned instead of the global one. Otherwise, the global log target is returned.

Return type: Log

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static GetLogLevel()

Returns the current log level limit.

All messages at levels strictly greater than the value returned by this function are not logged at all.

Return type:LogLevel

See also

SetLogLevel , IsLevelEnabled

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static GetRepetitionCounting()

Returns whether the repetition counting mode is enabled.

Return type:bool

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static GetTimestamp()

Returns the current timestamp format string.

Notice that the current time stamp is only used by the default log formatter and custom formatters may ignore this format.

Return type:string

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static GetTraceMasks()

Returns the currently allowed list of string trace masks.

Return type:list of strings

See also

AddTraceMask .

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static GetVerbose()

Returns whether the verbose mode is currently active.

Return type:bool

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static IsAllowedTraceMask(mask)

Returns True if the mask is one of allowed masks for LogTrace.

See also: AddTraceMask , RemoveTraceMask

Parameters:mask (string) – Return type:bool

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static IsEnabled()

Returns True if logging is enabled at all now.

Return type:bool

See also

IsLevelEnabled , EnableLogging

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static IsLevelEnabled(level, component)

Returns True if logging at this level is enabled for the current thread.

This function only returns True if logging is globally enabled and if level is less than or equal to the maximal log level enabled for the given component.

Parameters:

• level (LogLevel) –
• component (string) –

Return type:

bool

New in version 2.9.1.

See also

IsEnabled , SetLogLevel , GetLogLevel , SetComponentLevel

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LogRecord(self, level, msg, info)

Log the given record.

This function should only be called from the DoLog() implementations in the derived classes if they need to call DoLogRecord on another log object (they can, of course, just use Log.DoLogRecord call syntax to call it on the object itself). It should not be used for logging new messages which can be only sent to the currently active logger using OnLog() which also checks if the logging (for this level) is enabled while this method just directly calls DoLog().

Example of use of this class from LogChain:

def DoLogRecord(self, level, msg, info):

    # let the previous logger show it
    if self.logOld and IsPassingMessages():
        self.logOld.LogRecord(level, msg, info)

    # and also send it to the one
    if self.logNew and self.logNew != self:
        self.logNew.LogRecord(level, msg, info)

Parameters:

• level (LogLevel) –
• msg (string) –
• info (LogRecordInfo) –

New in version 2.9.1.

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static RemoveTraceMask(mask)

Remove the mask from the list of allowed masks for LogTrace.

Parameters:mask (string) –

See also

AddTraceMask

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static Resume()

Resumes logging previously suspended by a call to Suspend .

All messages logged in the meanwhile will be flushed soon.

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static SetActiveTarget(logtarget)

Sets the specified log target as the active one.

Returns the pointer to the previous active log target (may be None). To suppress logging use a new instance of LogNull not None. If the active log target is set to None a new default log target will be created when logging occurs.

Parameters:logtarget (Log) – Return type: Log

See also

SetThreadActiveTarget

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static SetComponentLevel(component, level)

Sets the log level for the given component.

For example, to disable all but error messages from wxWidgets network classes you may use

wx.Log.SetComponentLevel("wx./net", wx.LOG_Error)

SetLogLevel may be used to set the global log level.

Parameters:

• component (string) – Non-empty component name, possibly using slashes ( / ) to separate it into several parts.
• level (LogLevel) – Maximal level of log messages from this component which will be handled instead of being simply discarded.

New in version 2.9.1.

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SetFormatter(self, formatter)

Sets the specified formatter as the active one.

Parameters:formatter (LogFormatter) – The new formatter. If None, reset to the default formatter. Return type: LogFormatter

Log object later.

New in version 2.9.4.

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static SetLogLevel(logLevel)

Specifies that log messages with level greater (numerically) than logLevel should be ignored and not sent to the active log target.

Parameters:logLevel (LogLevel) –

See also

SetComponentLevel

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static SetRepetitionCounting(repetCounting=True)

Enables logging mode in which a log message is logged once, and in case exactly the same message successively repeats one or more times, only the number of repetitions is logged.

Parameters:repetCounting (bool) –

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static SetThreadActiveTarget(logger)

Sets a thread-specific log target.

The log target passed to this function will be used for all messages logged by the current thread using the usual Log functions. This shouldn’t be called from the main thread which never uses a thread- specific log target but can be used for the other threads to handle thread logging completely separately; instead of buffering thread log messages in the main thread logger.

Notice that unlike for SetActiveTarget , wxWidgets does not destroy the thread-specific log targets when the thread terminates so doing this is your responsibility.

This method is only available if USE_THREADS is 1, i.e. wxWidgets was compiled with threads support.

Parameters:logger (Log) – The new thread-specific log target, possibly None. Return type: Log Returns:The previous thread-specific log target, initially None.

New in version 2.9.1.

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static SetTimestamp(format)

Sets the timestamp format prepended by the default log targets to all messages.

The string may contain any normal characters as well as % prefixed format specifiers, see strftime() manual for details. Passing an empty string to this function disables message time stamping.

Notice that the current time stamp is only used by the default log formatter and custom formatters may ignore this format. You can also define a custom LogFormatter to customize the time stamp handling beyond changing its format.

Parameters:format (string) –

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static SetVerbose(verbose=True)

Activates or deactivates verbose mode in which the verbose messages are logged as the normal ones instead of being silently dropped.

The verbose messages are the trace messages which are not disabled in the release mode and are generated by LogVerbose.

Parameters:verbose (bool) –

See also

Log Classes Overview

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static Suspend()

Suspends the logging until Resume is called.

Note that the latter must be called the same number of times as the former to undo it, i.e. if you call Suspend twice you must call Resume twice as well.

Note that suspending the logging means that the log sink won’t be flushed periodically, it doesn’t have any effect if the current log target does the logging immediately without waiting for Flush to be called (the standard GUI log target only shows the log dialog when it is flushed, so Suspend works as expected with it).

See also

Resume , LogNull