couchdb/_design/trending/views/podcasts/map.js

   1 function(doc)
   2 {
   3     function getLanguage(podcast)
   4     {
   5         if (podcast.language)
   6         {
   7             return podcast.language.slice(0, 2);
   8         }
   9
  10         return null;
  11     };
  12
  13     function doEmit(language, prev, cur)
  14     {
  15         if(prev == 0)
  16         {
  17             return;
  18         }
  19
  20         if(cur <= 10)
  21         {
  22             return;
  23         }
  24
  25         var change = cur / prev;
  26
  27         /* we only emit improvements */
  28         if(change <= 1)
  29         {
  30             return;
  31         }
  32
  33         emit(["", change], null);
  34
  35         if(language)
  36         {
  37             emit([language, change], null);
  38         }
  39     }
  40
  41
  42     if(doc.doc_type == "Podcast")
  43     {
  44         var len = doc.subscribers.length;
  45         if(len < 1)
  46         {
  47             return;
  48         }
  49
  50         if (len < 2)
  51         {
  52             var prev = 1;
  53         }
  54         else
  55         {
  56             var prev = doc.subscribers[len-2].subscriber_count;
  57         }
  58
  59         var cur = doc.subscribers[len-1].subscriber_count;
  60
  61         var language = getLanguage(doc);
  62
  63         doEmit(language, prev, cur);
  64     }
  65     else if(doc.doc_type == "PodcastGroup")
  66     {
  67         var prev = 0;
  68         var cur = 0;
  69         var language = null;
  70
  71         for(var n in doc.podcasts)
  72         {
  73             var podcast = doc.podcasts[n];
  74             var len = podcast.subscribers.length;
  75
  76             if (len >= 1)
  77             {
  78                 cur += podcast.subscribers[len-1].subscriber_count;
  79             }
  80
  81             if (len >= 2)
  82             {
  83                 prev += podcast.subscribers[len-2].subscriber_count;
  84             }
  85
  86             if(!language)
  87             {
  88                 language = getLanguage(podcast);
  89             }
  90         }
  91
  92         doEmit(language, prev, cur);
  93
  94     }
  95 }