[slf4j-dev] slf4j i8ln

[Ralph Goers]

On Aug 19, 2009, at 8:31 AM, Pete Muir wrote:

> Hi Ralph,
>
> Whether or not resource bundles suck in our opinion, they are the  
> standard approach to this so I believe we can't just dismiss them.

Let me rephrase. It isn't just that they suck. In my environment  
resource bundles don't work for I18N. I'm not in favor of having  
features implemented that I can't use. But my opinion doesn't really  
carry any more weight than yours.

>
> I'm also unsure how, in your approach, a framework would provide  
> i8ln'ized log messages which would be used?

As I've said, I'm not at all in favor of SLF4J "doing" I18N. It is  
better to do it under a framework such as Spring's MessageSource  
interface where you can either use the default implementation, which  
uses ResourceBundles, or easily provide your own. As I said, I'm also  
planning on creating a framework to manage internationalized messages  
using Commons Configuration and XML files.

In that scenario the application either calls getMessage() and then  
passes the resulting String to the log call or the application passes  
the message key as the message on the log call, which is the approach  
I would suggest. In the second scenario it is up to the Appender to  
resolve the key by calling getMessage(). Ideally, the Appender should  
be able to tell whether it is getting a key or the actual message  
text. This can be done simply by convention - i.e. a log message like  
"key=Message1" or by passing a parameter. There is no real need to  
enhance SLF4J to be able to do this.

The piece that SLF4J is missing is the ability to detect the target  
Locale of the message. But even this can be handled without change to  
SLF4J. Just adding the Locale to the MDC would allow the Appender to  
do the right thing. Of course, you'd have to use a logging  
implementation that supports the MDC.

In short, instead of asking for a change to SLF4J it would make more  
sense to me for you to ask for an enhancement to Logback so that any  
Appender can have the opportunity to internationalize the message.  
Currently you'd have to do that in a Layout, but I don't believe all  
Appenders support them.

Ralph