gistfile1.js

activeUnits: function(){
    console.log('activeUnits');
    var us = this.get('units');
    
    if (us == this.previousUnits) return this.previousActiveUnits;
    
    this.previousUnits = us;
    
    var l = us.get('length');
    var list = [];
    var deleted = [];
    var i, u, j, d;
    
    for (i=0; i < l; i++) {
      u = us.objectAt(i);
      if ( list.indexOf(u) >= 0 ) {
        // don't add this again!
      }
      else {
        d = u.get('deletes');
        if ( d )  deleted.push(d);
        else      list.push(u);
      }
    }
    
    l = deleted.length;
    for (i=0; i < l; i++) {
      j = list.indexOf(deleted[i])
      if (j>=0){
        list.splice(j,1);
      }
    }
    
    this.previousActiveUnits = list;
    return list;
  }.property(),