Use map instead of 'if' where applicable

[oxpa]

vincent.bernat.ch/layout/nginx.j2

Line 50 in b1fd00d

{% for code, lang in languages %}

this part:

{% for code, lang in languages %}
  if ($http_accept_language ~* ^{{code}}) {
    # Not safe, but it seems to work. May change depending on the outer directives.
    set $lang {{code}};
  }
{% endfor %}

can be replaced with:

map $http_accept_language $lang {
{% for code, lang in languages %}
^{{code}} {{code}};
{% endfor %}
default en;
}

which reduces the size of configuration (and let you avoid IFs).
You can make it even more interesting by composing a more complex RE with capture like:
^(?<language>(en|fr|de)) $language
Which will result in only two lines: one RE for languages and one default.

[vincentbernat]

Thanks for the tip! Unfortunately, a map can only be defined at the http level and this file is included at the server level. I have added the "not safe" comment recently to remind me it currently works because of the outer directives. Even fixed, it's still not a correct solution if your preferred language is not one supported but you have another language as a fallback. A solution would be this C module (https://github.com/giom/nginx_accept_language_module/) or an alternative Lua implementation.