Importance of Direction of Control-Drag Operation while Setting Actions in Interface Builder

Question

I have a question regarding the importance of choosing the correct starting and ending points of a control-drag operation while setting actions using Interface Builder (3.2.3). This issue came up while working through an example in an introductory text. In the example project there is a very simple graphical window with a three NSTextFields (i.e. First Name, Last Name, Email) and one NSTextView. The interface for the controller class is declared in the header file as:

@interface EmailController : NSObject {

 IBOutlet NSTextField *emailField;
 IBOutlet NSTextField *firstNameField;
 IBOutlet NSTextField *lastNameField;
 IBOutlet NSTextView *resultTextView;

}

- (IBAction)textFieldChanged:(id)sender;

@end

The text makes a point in stating that when setting an action you begin the control-drag at the control. Specifically, the example starts with a control-drag from the First Name editable NSTextField text field to the EmailController instance where a small black window appears and where the action textFieldChanged action can be selected.

After the First Name editable box is connected to the action the text directs the reader to also connect the Last Name and Email editable boxes to the same action. However in these cases the text directs the reader to start the control-drag operation from the small circle to the right side of the textFieldChanged action in the black window of the controller instance and to end at the Last Name and Email editable boxes. This seems opposite to how I understand the general rule of starting at the control while setting an action.

No matter which points I choose as my start and my end I seem to get the same result. The actions listed in the Connector Inspector for the various objects always seem indifferent to which point I choose as my start. I wouldn't even consider it an issue if it wasn't that it seemed contradictory to the explicitly stated general rule. I did notice a problem when I tried doing the same thing with outlets.

Does it matter which point you choose as the start when connecting a control to an action?

Thanks

Answer 1

Does it matter which point you choose as the start when connecting a control to an action?

No.

Big Nerd Ranch recommends always dragging from sender to receiver (outlet to object or control to target) to make clear which direction the message(s) will go in. It's equally valid to drag in the other direction, but does not reinforce the message direction to new Cocoa and Cocoa Touch programmers.

(To be clear, that blog is authored by a former BNR class attendee, not by BNR or anyone working for BNR.)

After the First Name editable box is connected to the action the text directs the reader to also connect the Last Name and Email editable boxes to the same action. However in these cases the text directs the reader to start the control-drag operation from the small circle to the right side of the textFieldChanged action in the black window of the controller instance and to end at the Last Name and Email editable boxes. This seems opposite to how I understand the general rule of starting at the control while setting an action.

One advantage of the right-click-on-action-receiver-and-drag-from-the-actions way is that it's easier to connect a bunch of actions at once. That sounds like the best reason for the tutorial making an exception there, aside from just being by a different author or authors (I'm guessing) with a different way of doing things.