To let the user input new names you create a new view controller.

 Set up the view controller for new names

This creates three files: the NewNameViewController (.h) header and implementation (.m) file, as well as a XIB file that can be edited in Interface Builder. To group all the XIB files together, you can move it to the Resources folder where two XIB files already exist (the MainWindow and RootViewController's XIB files).

Before editing the XIB file to contain the text field, you must first add an Outlet property to the header so that you can tie in the text field from the XIB file into the code as well as an action to perform when the user has finished entering the name. Add the following to the NewNameViewController.h file

@interface NewNameViewController : UIViewController { 
UITextField *newNameField; 
} 
@property (retain) IBOutlet UITextField *newNameField; 
- (IBAction)doneAdding:(id)sender; 
@end 

Synthesize the property in the implementation file and release the text field in the dealloc method. You define the action later, once the DataAccess object can insert new names. For now, simply create an empty method stub in NewNameViewController.m to avoid compilation warnings.

@synthesize newNameField; 
- (IBAction)doneAdding:(id)sender {} 

The IBAction keyword lets Interface Builder know that the method should be made available for events to call. Make sure to save the header so that Interface Builder knows about the method.

Now that the outlet is set up, double-click the NewNameViewController XIB file to edit it in Interface Builder. In Interface Builder, you should see an empty view with a status bar showing the battery charging. Since this view also has a navigation bar showing, simulate showing it by doing the following:

The view should now show an empty navigation bar just below the status bar.

To allow the user to input a new name, add a text field to the view:

To make the text field more user-friendly, you can change a few properties:

For the controller to be made aware of when the user has finished entering the name, you must make action connections in Interface Builder.

In order to refer to the text field in the code, you need to connect this text field to the IBOutlet property you defined in the header earlier.

To finish the view, you need to set a few more properties in code. Uncomment the viewDidLoad method template in the NewNameViewController implementation and replace it with the following code:

- (void)viewDidLoad {
    [super viewDidLoad]; 
    
    // Set the title to display in the nav bar 
    self.title = @"Add Name"; 
    
    // Set the text field to the first responder to display the keyboard. 
    // Without this the user needs to tap on the text field. 
    [newNameField becomeFirstResponder]; 
}

To display the view controller you just created, the RootViewController needs to be configured. Import the NewNameViewController and DataAccess headers in the RootViewController's implementation file and add the following method signature to its header (RootViewController.h):

- (void)showAddNameScreen; 

Implement the method in RootViewController.m with the following code:

- (void)showAddNameScreen { 
    NewNameViewController * addNameScreen = [[NewNameViewController alloc]  
                                             initWithNibName:@"NewNameViewController" bundle:nil]; 
    [self.navigationController pushViewController:addNameScreen animated:YES]; 
}

Set the title of the RootViewController (the same way you set the title for the NewNameViewController), as well as add a plus-sign button to the right side of the navigation bar that calls showAddNameScreen. Uncomment the viewDidLoad block and replace it with the following code:

- (void)viewDidLoad { 
    [super viewDidLoad]; 
    // The Navigation Controller uses this to display the title in the nav bar. 
    self.title = @"Names"; 
    // Little button with the + sign on the right in the nav bar 
    self.navigationItem.rightBarButtonItem = 
    [[UIBarButtonItem alloc] 
     initWithBarButtonSystemItem:UIBarButtonSystemItemAdd 
     target:self 
     action:@selector(showAddNameScreen)]; 
}

To insert the new names into the database, you add functionality to the DataAccess object. Add the following method signature to the DataAccess header:

// Adds the given name to the database. 
- (void)addName:(NSString *)name; 

Implement the addName method in the implementation file:

- (void)addName:(NSString *)name {
    const char *            INSERT = "INSERT INTO Names(name) VALUES(?)";
    ULPreparedStatement *    prepStmt = connection->PrepareStatement(INSERT);
    
    if (prepStmt) {
        // Convert the NSString to a C-Style string using UTF8 Collation
        prepStmt->SetParameterString(1, [name UTF8String], [name length]);
        prepStmt->ExecuteStatement();
        prepStmt->Close();
        connection->Commit();
    } else {
        NSLog(@"Could not prepare INSERT statement.");
    }
}

Now that the addName method is complete, add the NewNameViewController's doneAdding method to the implementation file. Replace the method with the following code:

- (IBAction)doneAdding:(id)sender {
    if (newNameField.text > 0) { 
        [[DataAccess sharedInstance] addName:newNameField.text]; 
    } 
    [self.navigationController popViewControllerAnimated:YES]; 
}

Import the DataAccess header in NewNameViewController.h. This allows the keyboard's Done button to add the name to the database and return to the table view at runtime. However, the table view is not yet configured to display what is in the database. See Lesson 4: Displaying data from the database.

At this point you should build the application to test that it builds without errors. From the Build menu, click Build.