Dropbox iOS API - Simple Questions / DBRestClient Problems - ios

Question

EDIT:
I think I have fixed my issues. Thank you for the help - I really appreciate it.
Original Question:
I am new to objective-c and iOS programming, so hopefully my issues are not difficult to correct. I am trying to add the ability to open a file from Dropbox to my simple iOS application. I have been following the tutorial here:
http://www.mathiastauber.com/integration-of-dropbox-in-your-ios-application-making-api-calls/
I have so far successfully gotten my app to link to my Dropbox account and display the "link successful" message.
Now I am having trouble using the DBRestClient. I have the following code currently:
myviewcontroller.h
...
#end
DBRestClient *restClient;
myviewcontroller.m
- (DBRestClient *)restClient {
if (!restClient) {
restClient =
[[DBRestClient alloc] initWithSession:[DBSession sharedSession]];
restClient.delegate = self;
}
return restClient;
}
I am getting an error on the line
restClient.delegate = self;
that says
"Assigning to 'id<DBRestClientDelegate>' from incompatible type 'myviewcontroller'"
What could be going wrong? I have read through every example I can find and can see no issues with what I am trying to do.
If I try to cast by doing the following, it does not work
restClient.delegate = (id)self;
I have also found that if I remove the code in myviewcontroller.m and only have the variable declaration in the header file (as shown above) I get an error that says "Apple Mach-O Linker Error"
I would greatly appreciate any help you can provide. I am very much stuck with this problem.

Answer 1

In your header file you need to specify that you adhere to the DBRestClientDelegate's protocol.
For example:
#interface MyViewController: UIViewController <DBRestClientDelegate>
If you're already adhering to other protocols, simply add the DBRestClientDelegate and comma seperate, such as...
#interface MyViewController: UIViewController <UITableViewDelegate, DBRestClientDelegate>
For more information, I'd recommend a read of the Delegation section of Cocoa Core Competencies, especially as you'll be encountering delegates (and indeed perhaps defining your own protocols, etc.) a lot in Cocoa.

Answer 2

The error is because the right side of restClient.delegate = self; is not of type id<DBRestClientDelegate>
id<DBRestClientDelegate> is basically any object that conforms to the DBRestClientDelegate protocol
The first step (maybe only step) to removing the error is in your Myviewcontroller.h file
change
#interface Myviewcontroller : UIViewController //<-- my best guess at your interface line
to
#interface Myviewcontroller : UIViewController <DBRestClientDelegate>