User:JackSchmidt/JS ShowHiddenCats.js

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Documentation for this user script can be added at User:JackSchmidt/JS ShowHiddenCats.

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function JS_ShowHiddenCats() {
  JS_API(
    {action:"query",prop:"categories",titles:wgPageName,format:"json"},
    "cat",
    function(id,txt) {
      var p = eval("(" + txt + ")");
      var cats = [];
      for ( var pageid in p["query"]["pages"] ) {
        pagecats = p["query"]["pages"][pageid]["categories"];
        for ( var catkey in pagecats ) {
          var cat = pagecats[catkey]["title"];
          cat = cat.substring(9);
          cats.push(cat);
        }
      }
      var catlinks = document.getElementById("catlinks");
      if(catlinks == null) {
        catlinks = document.createElement("div");
        document.getElementById("bodyContent").appendChild(catlinks);
      }
      catlinks.appendChild( document.createTextNode('Hidden categories: ') );
      var viscats = catlinks.getElementsByTagName("a");
      for ( var a in viscats ) {
        a = viscats[a].title;
        viscats[a] = a;
      }
      for ( var cat in cats ) { 
        cat = cats[cat];
        var title = 'Category:' + cat;
        if( viscats[title] == title ) continue;
        var a = document.createElement("a");
        a.href = '/wiki/' + title;
        a.title = title;
        a.appendChild( document.createTextNode(cat) );
        catlinks.appendChild( document.createTextNode(' | ') );
        catlinks.appendChild( a );
        if(addTooltip) addTooltip(a);
      }
    }
  );
};

$( JS_ShowHiddenCats );