Sending ABC to a parameter of incompatible type 'id<NSXMLParserDelegate>

[Jean Jacques]

Hello guys, my app is working (almost...) the way I want it to, but I want to have a 0 error/warning app and I can't figure this one out..

My code:

@implementation VideoController

-(void)awakeFromNib
{
	NSString *dataFilePath = [[NSBundle mainBundle] pathForResource:@"video" ofType:@"xml"];
	stories = [[NSMutableArray alloc]init];
	parser = [[NSXMLParser alloc] initWithData:[NSData dataWithContentsOfFile:dataFilePath]];
	[parser setDelegate:self];
	[parser parse];
	NSLog(@"file trovato e caricato");

}

The warning, applying to the line above "[parser setDelegate:self];", is actually double:

Class 'VideoController' does not implement the 'NSXMLParserDelegate' protocol

Sending 'VideoController' to parameter of incompatible type 'id<NSXMLParserDelegate>'

I guess this part of the NSXMLParser.h file might relate to the above, since Xcode indicates it under Semantic issue relating to the warning "Sending...":

"- (void)setDelegateid <NSXMLParserDelegate>)delegate;" as follows:

1. Passing argument to parameter 'delegate' here

...and this is the context (in the .h file)

@interface NSXMLParser : NSObject {
@private
    void * _parser;
    id _delegate;
    id _reserved1;
    id _reserved2;
    id _reserved3;
}
- (id)initWithContentsOfURL:(NSURL *)url;  // initializes the parser with the specified URL.
- (id)initWithData:(NSData *)data; // create the parser from data

// delegate management. The delegate is not retained.
- (id <NSXMLParserDelegate>)delegate;
- (void)setDelegate:(id <NSXMLParserDelegate>)delegate;

What am I missing here? I am programming trial & error and am a total noob, so I will be very grateful for instruction in plain words, thanks a million

[baja_yu]

Your VideoController should adopt the NSXMLParserDelegate. Just add it in the header file.

On a side note, trial and error is really not a good approach in this field. You shouldn't be struggling with basics like this after a year. I suggest you read this document to learn the basic concepts of the platform: Loading… then this Loading… to learn the Objective C syntax.

[Jean Jacques]

Originally Posted by baja_yu

Your VideoController should adopt the NSXMLParserDelegate. Just add it in the header file.

On a side note, trial and error is really not a good approach in this field. You shouldn't be struggling with basics like this after a year. I suggest you read this document to learn the basic concepts of the platform: Loading… then this Loading… to learn the Objective C syntax.

Thanks a lot for your quick input. I tried to add "NSXMLParserDelegate" to both .m and .h file, but as soon as I did it, there was a red warning... Could you please tell me where precisely should I put it?

On a side note, totally agree, I will be learning fundamentals as soon as I get rid of this app which I really need to complete asap

[baja_yu]

There are no red warnings, those are errors. And it would help if you posted the exact error message. Also post what you tried when you added the delegate to the class.

[stuartervine]

Hi Jean,

I realise this is a very late response to your question, however it came out as the number 1 google hit on searching for 'passing argument to parameter', so I thought I'd respond with another case where this can happen.

I've found the 'passing argument to parameter' note occurs when a usage of the method the note is against actually receives an incompatible type. If this is the case, you should see a corresponding warning in your compile output stating something like... 'incompatible pointer types sending 'NSString *' to parameter of type 'MyObject *'. When you correct this warning, the note should disappear.