Re: [PATCH] http: Add Accept-Language header if possible

From: Peter Krefting <peter@softwolves.pp.se>
Date: Jul 9, 2014, 10:40 UTC
Message-ID: <alpine.DEB.2.00.1407091127490.22132@ds9.cixit.se>
In-Reply-To: <1404834846-11812-1-git-send-email-eungjun.yi@navercorp.com>

Yi EungJun:

> Example:
>  LANGUAGE= -> ""
>  LANGUAGE=ko -> "Accept-Language: ko; q=1.000, *; q=0.001"
>  LANGUAGE=ko:en -> "Accept-Language: ko; q=1.000, en; q=0.999, *; q=0.001"

Avoid adding "q=1.000". It is redundant (the default for any unqualified language names is 1.0, and additionally there has historically been some buggy servers that failed if it was included.

> +	p1 = getenv("LANGUAGE");

You need a fallback mechanism here to parse all the possible language variables. I would use the first one I find of these:

  1. LANGUAGE
  2. LC_ALL
  3. LC_MESSAGES
  4. LANG

Only "LANGUAGE" holds a colon-separated list, but the same code can parse all of them, just yielding a single entry for the others.

> +				strbuf_add(buf, p1, p2 - p1);

The tokens are on the form language_COUNTRY.encoding@identifier, whereas Accept-Language wants language-COUNTRY, so you need to a) replace "_" with "-", and b) chop off anything following a "." or "@".

> +				strbuf_addf(buf, "; q=%.3f", q);
> +				q -= 0.001;

Three decimals seems a bit overkill, but some experimentation might be necessary.

> +		strbuf_addstr(buf, "*; q=0.001\r\n");

You should probably also add an explicit "en" here, if none was already included. I've seen some servers break horribly if "en" isn't included.

For reference, I have my LANGUAGE variable set to "sv_SE.utf8:sv:nb_NO.utf8:nb:da_DK.utf8:da:nn_NO.utf8:nn:en_GB.utf8:en_US.utf8:en"

-- 
\\// Peter - http://www.softwolves.pp.se/