How to debug code? (through log)

Here we can see debugging code technique:

  • For File Log System:

    system log, exception log and your log file
    First need to Enable Log settings from admin:
    Go to Admin -> System -> Configuration -> Developer -> Log Settings -> Enable.
    The log files for both system and exception stores in {{base_dir}}/var/log.
    To do system log we have to use “Mage::log()” and to do exception log we have to use “Mage::logException()”.
    Ex:
    Write your log:
    Mage::log(“For Testing”);
    Mage::log(“For Testing”, null, “ourfile.log”);
    Mage::logException(“Test log Exception”);

  • Write Debug Backtrace:

    Put it in a function which we have to check where it is called
    $tracelog = Varien_Debug::backtrace(true, true);
    Mage::log($tracelog);
    OR
    Mage::log(Varien_Debug::backtrace(true, true), null, ‘backtrace.log’);

  • Log Class/Method:

    Mage::log( get_class($object)) # name of class
    Mage::log( get_class_methods($object)) # methods of class

  • Write Your Profiler in between code:

    We can use following line for write a profile section with own tags/keyword
    We can use your own keyword which is display in profiler.
    Ex:
    Varien_Profiler::start(‘YOUR_OWN_KEYWORD’);
    $this->_afterLoad();
    Varien_Profiler::stop(‘YOUR_OWN_KEYWORD’);
    Note: keyword must be same in start and stop