title: Core Plot: how to refresh graph which is embedded in a tab?
body: <p>I have a graph embedded in tab. In the second tab, I have a table view display the same data in a table, using NSFetchResultController. 
  The TabBar Controller is embedded in a Navigation Controller, which has an Add-Button in the right top of its navigation bar. This button modally segues a view controller, where the user can add a new object/record. 
  While the table view is correctly updated, when the user adds a record, the tab with core plot graph is not refreshed.</p>
  
  <p>Here is my code in the first tab (in viewWillAppear):</p>
  
  <pre><code>self.bmisForPlot = [[self fetchBmisForPlot] copy];
  [graph reloadData];
  </code></pre>
  
  <p>where <code>self.bmisForPlot</code>is an array carrying the data for the graph.</p>
  
  <p>In the Tabbar Controller (which I subclassed):</p>
  
  <pre><code>- (void)tabBarController:(UITabBarController *)tabBarController
   didSelectViewController:(UIViewController *)viewController
   {
      NSLog(@"controller class: %@", NSStringFromClass([viewController class]));
      if ([NSStringFromClass([viewController class]) isEqualToString:@"MRBMIKurveViewController"]) 
      {
          MRBMIKurveViewController *kurveViewController = (MRBMIKurveViewController *) viewController;
          kurveViewController.bmisForPlot = [[kurveViewController fetchBmisForPlot] copy];
          [kurveViewController.graph reloadData];
          NSLog(@"switched to MRIKurveViewController");
      }
  }
  </code></pre>
  
  <p>This method is called, when the user switches tabs, but the graph is NOT refreshed?</p>
  
  <p>Is there a way to force refreshing a graph?</p>
  
  <p>The table view gets updated because its data source is a NSFetchedResultsController, but I don't know if and how can I use a NSFetchedResultsController in conjunction with a core plot graph?</p>
  
  <p>Or is there another way? </p>