gistfile1.js

  /** @private - setup observer on init if needed. */
  init: function() {
    sc_super();
    if (this.get('content')) this._scoc_contentDidChange();
    if (this.get('observableContent')) this._scoc_observableContentDidChange();
  },

  _scoc_contentDidChange: function () {
    var last = this._scoc_content,
        cur  = this.get('content');
        
    if (last !== cur) {
      var cofunc = this._scoc_contentObjectsDidChange;
      if (last && last.isEnumerable) last.removeObserver('[]', this, cofunc);
      if (cur && cur.isEnumerable) cur.addObserver('[]', this, cofunc);
    }
  }.observes("content"),
  
  _scoc_contentObjectsDidChange: function () {
    this.propertyDidChange('content');
  },