// use the default logger instance:
$logger = Zend_Registry::get('logger');
/* @var $logger ZfExtended_Logger */
$logger->info('E1234', 'This is the message for the log where {variable} can be used.', [
	'mydebugdata' => "FOOBAR can be an object or array too",
    'variable' => "This text goes into the above variable with curly braces",
]);

-- instead of 
select * from Zf_errorlog;
-- use for better readability:
select * from Zf_errorlog\G

// activates the duplication recognition by the formatted and rendered error message.
// for places where event codes are added with editor_Services_Connector_Exception::addCodes just add the addDuplicates calls directly afterwards.
// so the messages 'Test Error for "FOO"' and 'Test Error for "BAR"' are considered different, even if the event code is the same, and also the message template is the same: 'Test Error for "{variable}"'
ZfExtended_Logger::addDuplicatesByMessage('E1317', 'E1318'); 

//Configured that way, the variables in the message will play no role anymore:
ZfExtended_Logger::addDuplicatesByEcode('E1319', 'E1234'); 

// if duplication recognition should be used for events defined in exceptions, just override the template function ZfExtended_ErrorCodeException::setDuplication: 

class Demo_Exception extends ZfExtended_ErrorCodeException {

    static protected $localErrorCodes = [
        'E1234' => 'Demo Error.',
    ];

    protected function setDuplication() {
        parent::setDuplication();
        ZfExtended_Logger::addDuplicatesByMessage('E1234');
    }
}

core                                ./library/ZfExtended/Exception.php
core                                ./library/ZfExtended/Logger.php
core.api.filter						./library/ZfExtended/Models/Filter/Exception.php
core.entity                         ./library/ZfExtended/Models/Entity/Exceptions/IntegrityConstraint.php
core.entity                         ./library/ZfExtended/Models/Entity/Exceptions/IntegrityDuplicateKey.php
core.worker                         ./library/ZfExtended/Worker/TriggerByHttp.php
core.authentication
editor.customer                     ./application/modules/editor/Controllers/CustomerController.php
editor.export.difftagger            ./application/modules/editor/Models/Export/DiffTagger/Exception.php
editor.export.fileparser            ./application/modules/editor/Models/Export/FileParser/Exception.php
editor.import                       ./application/modules/editor/Models/Import/Exception.php
editor.import.configuration         ./application/modules/editor/Models/Import/ConfigurationException.php
editor.import.fileparser            ./application/modules/editor/Models/Import/FileParser/Exception.php
editor.import.fileparser.csv        ./application/modules/editor/Models/Import/FileParser/Csv/Exception.php
editor.import.fileparser.sdlxliff   ./application/modules/editor/Models/Import/FileParser/Sdlxliff/Exception.php
editor.import.fileparser.xlf        ./application/modules/editor/Models/Import/FileParser/Xlf/Exception.php
editor.import.metadata              ./application/modules/editor/Models/Import/MetaData/Exception.php
editor.import.metadata.pixelmapping ./application/modules/editor/Models/Import/MetaData/PixelMapping.php
editor.import.relais                ./application/modules/editor/Models/RelaisFoldertree.php
editor.languageresource.service     ./application/modules/editor/Services/Manager.php
editor.languageresource.service     ./application/modules/editor/Services/NoServiceException.php
editor.languageresource.taskassoc   ./application/modules/editor/Controllers/LanguageresourcetaskassocController.php
editor.segment                      ./application/modules/editor/Models/Segment/Exception.php
editor.segment                      ./application/modules/editor/Models/Segment/UnprocessableException.php
editor.segment.pixellength          ./application/modules/editor/Models/Segment/PixelLength.php
editor.terminology					./application/modules/editor/Models/Term/TbxCreationException.php
editor.task                         ./application/modules/editor/Controllers/TaskController.php
editor.task.exceleximport           ./application/modules/editor/Models/Excel/ExImportException.php
editor.workflow                     ./application/modules/editor/Logger/Workflow.php
editor.workflow.notification        ./application/modules/editor/Workflow/Actions/Abstract.php
plugin.groupshare                   ./application/modules/editor/Plugins/GroupShare/Exception.php
plugin.groupshare.httpapi.tmservice ./application/modules/editor/Plugins/GroupShare/HttpApiTMService.php
plugin.groupshare.httpapi.web       ./application/modules/editor/Plugins/GroupShare/HttpApiWebAPI.php
plugin.groupshare.token             ./application/modules/editor/Plugins/GroupShare/ExceptionToken.php
plugin.matchanalysis                ./application/modules/editor/Plugins/MatchAnalysis/Exception.php
plugin.okapi                        ./application/modules/editor/Plugins/Okapi/Exception.php

$log = Zend_Registry::get('logger');
/* @var $log ZfExtendend_Logger */
$log->error("TODO"); // logs an error
// must be enabled in the filters
$log->debug("TODO"); // logs a debug statement
$log->trace("TODO"); // logs a debug statement with stack trace
$log->logDev($data1, $data2, ...); // a convienent replacement for error_log(print_r($data, 1)); Only for development, should not be comitted!

// the WorkflowLogger - dedicated to translate5 tasks and workflow stuff - must be instanced manually:
// TODO

class Class_Or_Plugin_In_Which_I_Want_To_Log {
    use ZfExtended_Logger_DebugTrait; //→ use the debug trait to get several things

	public function __construct() {
		//before first usage init the logger:
        $this->initLogger('E1100', 'plugin.name.special.sub.stuff', 'plugin.name', 'Plug-In NAME: ');
		//	E1100 → specific error code for the domain to be logged (or general code if applicable)
		//	plugin.name.special.sub.stuff → the domain of the current scope to be logged
		//  plugin.name → the root domain which is used as check in the logger writer configuration. If this string occurs somewhere in the writer domain filters, the debug and trace function will do something
		//  Plug-In NAME: → a string prefix which is added to each debug and trace message.
    }

	public function doSomethingToUseTheLogger() {
		$this->log->warn("EXXXX", "Message", ['data' => 123]);  // by the trait $this->log is initialized with a logger using the domain "plugin.name.special.sub.stuff"
		$this->debug('Debug message', ['debugdata' => 123]);    // the trait provides the debug function, which uses the above configured ECode and prefix. Also it uses the configured domain. 
																// this debug statement can remain in the code. 
																// It will only do something if one of the log writers is configured with a filter with a domain containing 'plugin.name' and level debug
																// so multiple debug statements should not pull down the performance and will not waste the log by the default
		$this->trace('Message', ['debugdata' => 123]);			// basicly the same as debug() but with complete stack trace in the log. filter level must be trace so that this functions is soing something.
    }