[jira] [Commented] (LOG4PHP-177) logger writes every message twice

["Ivan Habunek (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/LOG4PHP-177?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13437379#comment-13437379 ] 

Ivan Habunek commented on LOG4PHP-177:
--------------------------------------

Sagi, 

I agree that this behaviour is somewhat inconsistent. You cannot attach an appender to a logger multiple times through configuration (although you can programatically).

In this case, the appender is attached to MyClass logger and the root logger (only once per logger). When root logger logs a message, it also forwards it to any parent loggers (which in this case is the root logger) because of the additivity rules. There is no check to see if the parent logger's appenders are also attached to MyClass logger. That's why the message gets logged twice by the same appender.

While I'm not sure that this behaviour is 100% desirable, I don't see that it causes a problem which cannot fixed by a simple change in configuration, as you demonstrated. Therefore, I'm not inclined to start complicating the code to fix this.

Perhaps this issue can best be solved by documenting the behaviour in question.
                
> logger writes every message twice
> ---------------------------------
>
>                 Key: LOG4PHP-177
>                 URL: https://issues.apache.org/jira/browse/LOG4PHP-177
>             Project: Log4php
>          Issue Type: Bug
>          Components: Code
>    Affects Versions: 2.2.1
>         Environment: windows 7, php 5.3 (bundled with xampp)
>            Reporter: Sagi Mann
>            Priority: Minor
>
> The following code and configuration logs everything twice, but is not expected to. This was attempted with both LoggerAppenderConsole and LoggerAppenderFile, maybe reproducible with other appenders as well. If I remove the <appender_ref> tag from the <logger name="MyClass"> element below, the issue no longer occurs, but AFAIU, this kind of workaround should not be required.
> log4php.xml:
> <configuration xmlns="http://logging.apache.org/log4php/">
>     <appender name="myAppender" class="LoggerAppenderConsole">
>     </appender>
>     <root>
>         <level value="WARN" />
>         <appender_ref ref="myAppender" />
>     </root>
>     <logger name="MyClass">
>         <level value="WARN" />
>         <appender_ref ref="myAppender" />
>     </logger>
> </configuration>
> index.php:
> Logger::configure('log4php.xml');
> class MyClass {
> 	protected $logger = null;
> 	public function __construct() { $this->logger = Logger::getLogger(get_class($this)); }
> 	public function f() { $this->logger->warn("f"); }
> }
> $cls = new MyClass();
> $cls->f();
> output:
> WARN - f
> WARN - f

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