QML Logging

Single-header only, Easylogging++ wrapper for advanced logging support for QML applications

                                   ‫بسم الله الرَّحْمَنِ الرَّحِيمِ

Manual For v1.3

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Release Notes

Samples

Project Homepage

Introduction

Provides functionalities to write logs and provides various other functionalities for your QML applications. You should check out Easylogging++ to see more exciting things you can do.

Getting Started

Download

Current stable release is http://qml.easylogging.org/latest.zip

Before you start, please read basics of Easylogging++ as this project is essentially a wrapper around the library, hence basic functionality is the same.

Quick Start

In order to get started with QML Logging, you can follow three easy steps;

• Download latest header (both Easylogging++ and QML Logging)
• Include into your project
• Initialize using single macro... and off you go!

#include "qmllogging.h"

_INITIALIZE_QMLLOGGING

int main(int argc, char* argv[]) {
   QGuiApplication app(argc, argv);
   // Following line is optional but always recommended to put this - needed by some functionalities
   _START_EASYLOGGINGPP(argc, argv);
   
   // Your Qml engine
   QQmlApplicationEngine engine(QUrl("..."));
   
   el::qml::QmlLogging::registerNew(engine.rootContext());
   
   // Or if you are using QtQuick2ApplicationViewer
   // QtQuick2ApplicationViewer viewer;
   // el::qml::QmlLogging::registerNew(viewer.rootContext());
   
   // ...
   
   return app.exec();
}

import org.easylogging.qml 1.1

...
log.info("I am info log")
...

Notes

1. Easylogging++ header

By default QML logging includes easylogging++.h using #include <easylogging++.h> but you can change it according to your need, this may not work in your system if you do not have library in your /usr/lib/ or alternative of it in MacOSX or Windows.

2. Default logger

Default logger for QML logging is qml. You can change this by passing second argument to registerNew function.

3. Log to file

By default, your QML application will also write to logs/ directory, you can disable this behaviour by reconfiguring default configurations (also update existing loggers). This configuration will have el::ConfigurationType::ToFile to false.

#include "qmllogging.h"

_INITIALIZE_QMLLOGGING

int main(int argc, char* argv[]) {
   // ... Your code
   _START_EASYLOGGINGPP(argc, argv);

   el::Configurations myConfigurations;
   myConfigurations.setGlobally(ConfigurationType::ToFile, "false");
   Loggers::setDefaultConfigurations(myConfigurations, true);
 
 
   // Your QML engine
   QQmlApplicationEngine engine(QUrl("..."));
   
   el::qml::QmlLogging::registerNew(engine.rootContext());
   
   // Or if you are using QtQuick2ApplicationViewer
   // QtQuick2ApplicationViewer viewer;
   // el::qml::QmlLogging::registerNew(viewer.rootContext());
   
   // ... Your code
}

Please note that some android devices do not allow to create logs/ directory or log file, please check permissions. And you are facing issues and do not see any log when doing remote debugging (or from adb shell), enable error viewing by defining _ELPP_DEBUG_ERRORS to see whats the issue.

4. Log to standard output

QML logging uses qDebug() to log to standard output (i.e, console or terminal). If you wish to disable this behaviour (and use std::cout and family instead), you can do so by defining macro _QMLLOGGING_AVOID_QDEBUG before including qmllogging.h file.

Remember, there are consequences of avoiding qDebug() as std::cout and family do not work quite well (they are pretty much useless) with Qt Quick, specially when you are debugging in emulator or device; Plus, using qDebug() helps you look at your log using adb logcat.

5. Default Flags

QML logging adds following flags

• DisableApplicationAbortOnFatalLog

6. Samples

Please see samples/ directory for samples. If a sample does not work, please feel free to report an issue on github with details.

API

Here is list of public functions

Logging

• info(msg, ...)
• warn(msg, ...)
• debug(msg, ...)
• error(msg, ...)
• fatal(msg, ...)
• trace(msg, ...)
• verbose(level, msg, ...)

Timing

• timeBegin(blockName)
• timeEnd(blockName)
• timeCheck(blockName)

Couting

• count(msg)
• countEnd(msg)

Assertion

• assert(condition, msg)

Licence

The MIT License (MIT)

Copyright (c) 2014 Majid Khan
http://easylogging.org/

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE