Enhance links to other languages on Wikipedia

wikipedia_language_labels.user.js

// ==UserScript==
// @name        Wikipedia Language Labels
// @namespace   org.maripo.neta
// @description Enhance links to other languages (e.g. Change "Français" to "Étoile (Français)" on http://en.wikipedia.org/wiki/Star )
// @include     http://*.wikipedia.org/wiki/*
// @grant       none
// @version     1
// ==/UserScript==


(function () {
    /*
        Customize labels by editing LABEL_STYLE.
        "LABEL", "LANG_CODE" and "LANG_NAME" will be replaced.
        
        e.g.
            "LABEL (LANG_NAME)" => "Étoile (Français)"
            "[LANG_CODE]LABEL" => "[fr]Étoile"
     */
    var LABEL_STYLE = 'LABEL (LANG_NAME)';
    
    var _REPLACEMENT_LABEL = 'LABEL';
    var _REPLACEMENT_LANG_CODE = 'LANG_CODE';
    var _REPLACEMENT_LANG_NAME = 'LANG_NAME';
    var _REGEXP_LINK = new RegExp('http:\/\/([a-z\-]+)\.wikipedia\.org\/wiki\/([^#]+)');
    var _REGEXP_SPACES = new RegExp('_', 'g');
    var links = document.getElementById('p-lang').getElementsByTagName('A');
    for (var i=0; i<links.length; i++) {
        var link = links[i];
        if (link.hreflang && link.href.match(_REGEXP_LINK)) {
            var langCode = RegExp.$1;
            var langName = link.innerHTML;
            var label = decodeURI(RegExp.$2).replace(_REGEXP_SPACES, ' ');
            link.innerHTML = LABEL_STYLE
                .replace(_REPLACEMENT_LABEL, label)
                .replace(_REPLACEMENT_LANG_CODE, langCode)
                .replace(_REPLACEMENT_LANG_NAME, langName);
        }
    }
})();