Re: Rack::CommonLogger does not receive Logger Instance. is this bug?

[James Tucker <jftucker@gmail.com>]

On 5 May 2010, at 13:03, sanemat wrote:
> Logger Instance does not have +write+ method.
> But Rack::CommonLogger's constructer require +write+ method in second
> parameter.

class MyLogger << Logger
  alias write <<
end

use Rack::CommonLogger, MyLogger.new

> modify way I think:
> a. change Logger instance
> b. change commonlogger
> 
> or anyway.
> 
> so i try 'a' way like below, and it works.
> 
> http://github.com/choonkeat/tweetstreamproxy/commit/ec82b0ac04b4f20ba33bf4f25dfb3f60e122d44c
>  Logger.class_eval { alias :write :"<<" } unless
> Logger.instance_methods.include? "write"

This is horrible. I do wish people would subclass first rather than monkey patch first (glaring evil stares at rails here too as there's no need to monkey patch Logger, like, ever).

> or 'b' way. like this.
> http://github.com/sanemat/rack/commit/865ab9655aa2aa226a9d21b8dfd39e001c9bdeb0
> change method again from +write+ to +<<+. this changed one years ago.
> http://github.com/rack/rack/commit/761c6246e18b92752353c0f412976ded4a417dc5

I see the implementation used to be compatible with Logger, that change did indeed break it. It uses write to expect something IO-ish, not something Logger-ish, but I think it would be a valid change to use << instead, however, I cannot remember if we specify this as a requirement for env['rack.errors']. Certainly we should decide one way, however, I have no real problem with the way it presently is, the implementation being simpler than it used to be.

> which is better?
> I confuse this.
> i may be wrong but few people use Logger?

Generally, no, people use env['rack.errors'], which is IO-ish.