SC.Collection

  /**
    Call this to force the list to refresh.  The refresh may not happen
    right away, depending on the dataSource.
  */
  refresh: function() {
    var recordType = this.get('recordType') || SC.Record ;
    var offset = (this._limit > 0) ? this._offset : 0 ;
    
    if (!this._boundRefreshFunc) {
      this._boundRefreshFunc = this._refreshDidComplete.bind(this) ;
    }    
    
    // start refresh
    if (!this.dataSource) throw "collection does not have dataSource" ;
    this.beginPropertyChanges();
    if (!this.isLoading) this.set('isLoading',true) ;
    this._refreshing = true ;
    
    var order = this.get('orderBy') ;
    if (order && !(order instanceof Array)) order = [order] ;
    this.dataSource.listFor({
      recordType: recordType,
      offset: offset, 
      limit: this._limit,
      conditions: this.get('conditions'), 
      order: order,
      callback: this._boundRefreshFunc,
      cacheCode: this._cacheCode
    }) ;
    this.endPropertyChanges() ;
    return this; 
  },