I have an interface:
#import <Foundation/Foundation.h>
#interface Picture : NSObject;
#property (readonly) NSString *filepath;
- (UIImage *)image;
#end
and implementation:
#import "Picture.h"
#define kFilepath #"filepath"
#interface Picture () <NSCoding> {
NSString *filepath;
}
#end
#implementation Picture
#synthesize filepath;
- (id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
return self;
}
- (void)encodeWithCoder:(NSCoder *)aCoder {
[aCoder encodeObject:filepath forKey:kFilepath];
}
- (UIImage *)image {
return [UIImage imageWithContentsOfFile:filepath];
}
#end
I get error: ARC issue - No visible #interface for 'NSObject' declares the selector' initWithCoder:'
Is there something different about NSCoding when using ARC?
Thanks
There's nothing different between ARC and manual reference counting. NSObject doesn't conform to NSCoding and therefore doesn't supply -initWithCoder: or -encodeWithCoder:. Just don't call through to the superclass implementations of those methods.
- (id)initWithCoder: (NSCoder *)aCoder {
self = [super init];
if (self) {
[aCoder decodeObject: filepath forKey: kFilepath];
}
return self;
}
Related
This is a weird bug.
I have this in the header:
#import "UIKit/UIKit.h"
#interface ProxyProfileObject : NSObject <NSCoding> {
NSString *profileName;
NSString *ipAddress;
NSString *port;
}
-(void) setProfileName:(NSString *)string;
-(NSString*) getProfileName;
-(void) setIP:(NSString *)string;
-(NSString*) getIP;
-(void) setPort:(NSString *)string;
-(NSString*) getPort;
#end
And this in the implementation:
#import "ProxyProfileObject.h"
#interface ProxyProfileObject()
#end
#implementation ProxyProfileObject
-(void) setProfileName:(NSString *)string{
profileName = string;
}
-(NSString*) getProfileName{
return profileName;
}
-(void) setIP:(NSString *)string{
ipAddress = string;
}
-(NSString*) getIP{
return ipAddress;
}
-(void) setPort:(NSString *)string{
port = string;
}
-(NSString*) getPort{
return port;
}
// Encoding stuff
- (id)initWithCoder:(NSCoder *)decoder {
if (self = [super init]) {
self.profileName = [decoder decodeObjectForKey:#"profileName"];
self.port = [decoder decodeObjectForKey:#"port"];
self.ipAddress = [decoder decodeObjectForKey:#"ip"];
}
return self;
}
- (void)encodeWithCoder:(NSCoder *)encoder {
[encoder encodeObject:profileName forKey:#"profileName"];
[encoder encodeObject:ipAddress forKey:#"ip"];
[encoder encodeObject:port forKey:#"port"];
}
#end
I am not sure why it does this. It shouldn't do it as ipAddress is the same thing as port or profile name.
Those are the two files. You can now see by yourself how ipAddress doesn't work.
In your header NSString *ipAddress declares an ivar.
I the implementation self.ipAddress refers to a property.
You declared no such property. Hence the error.
After the edit your problem becomes apparent:
You do not declare a method -(void)setIpAddress:(NSString *)address;
That's what would make Xcode allow you to use property syntax (dot notation) for the setter—even though it's not an actual property.
You are declaring instance variables, not properties. Just put the #property directive in front of the lines.
#interface ProxyProfileObject : NSObject <NSCoding> {}
#property NSString *profileName;
#property NSString *ipAddress;
#property NSString *port;
Edit: Don't write explicit getters and setters. Use the (error-free) synthesized accessors provided by the #property declaration.
My cpViewController has a button that modal segues to cpScanViewController. I want to have cpScanViewController inform ViewController with a string when it has completed a successful scan. After reading numerous articles online, I believe delegation is the best way to do this?
Is the delegate being set correctly?
How does the delegate inform the cpViewController?
cpScanViewController.h
#import <UIKit/UIKit.h>
#protocol ScanDelegate <NSObject>
-(void)receivedUPC:(NSString *)Scan;
#end
#interface cpScanViewController : UIViewController
#property (nonatomic, weak) id <ScanDelegate> delegate;
#property (nonatomic, retain) NSString *UPC;
-(void)checkUPC;
#end
cpScanViewController.m
#interface cpScanViewController ()
{
NSString *UPC;
}
#end
#implementation cpScanViewController
#synthesize delegate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
-(void)doSomeScanStuff
{
UPC = #"a string"
// even tried
[delegate receivedUPC:UPC];
}
-(void)checkUPC
{
}
#end
cpViewController.h
#import <UIKit/UIKit.h>
#import "cpScanViewController.h"
#interface cpViewController : UIViewController <ScanDelegate>
#end
cpViewController.m
#interface cpViewController ()
{
cpScanViewController *cp;
}
#end
#implementation cpViewController
- (void)viewDidLoad
{
// set delegate
cp = [[cpScanViewController alloc] init];
[cp setDelegate:self];
}
-(void)receivedUPC:(NSString *)Scan{
// Nothing happening
NSLog(#"%#", Scan);
NSLog(#"The %#", cp.UPC);
}
#end
Because you are not calling receivedUPC method from your cpScanViewController class. You need to add [_delegate receivedUPC:self], some where in order to invoke this delegat method in cpViewController class.
I was able to get it working by using the method:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
cpScanViewController *vd = (cpScanViewController *)[segue destinationViewController];
vd.delegate = self;
}
Because I made the connection in storyboards I didn't realize it needed to have the method.
Im getting only this failure after having built the project.
Im using the XCode 4.6.3
class.m
#import "Car.h"
//constructor
-(id)init //<----- ***MISSING CONTEXT FOR METHOD DECLARATION***
{
self = [super init];
if(self){
self.brand = #"";
self.model = #"";
self.vin = 0;
}
return self;
class.h contains no error.
#import <Foundation/Foundation.h>
#interface Car : NSObject
{
NSString *brand, *model;
NSNumber *vin;
}
//set
-(void) setBrand:(NSString *) newBrand;
-(void) setModel:(NSString *) newModel;
-(void) setVIN:(NSNumber *) newVIN;
//get
-(NSString *) getBrand;
-(NSString *) getModel;
-(NSNumber *) getVIN;
//methods
-(void) accelerateTo100;
-(void) fuelConsuming;
-(void) hardStop;
#end
Can you help me with this. Thanks alot.
Answer is what #CodaFi explained. Try this
#import "Car.h"
#implementation Car
-(id)init
{
self = [super init];
if(self){
[self setBrand : #""];
[self setMode1 : #""];
[self setVIN : #""];
}
return self;
}
#end
Implementations of methods related to the Car class are always wrapped in #implementation Car and terminated with an #end. You're declaring and implementing methods without telling the compiler which class they belong to.
Check that you don't have an #import "..." within the #implementation section.
I'm trying to implement saving of user preferences in my OS X app. I have an NSTableView which stores its data to my .plist file, but I have troubles loading same data back to my NSTableView.
My model object:
#import <Foundation/Foundation.h>
#interface UserKeys : NSObject <NSCoding>
#property (nonatomic, copy) NSString *userKeyName;
#property (nonatomic, copy) NSString *userApi;
#property (nonatomic, copy) NSString *userCode;
#end
and its implementation:
#import "UserKeys.h"
#implementation UserKeys
- (id)init
{
self = [super init];
if (self) {
//
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder {
self = [super init];
if (self) {
self.userKeyName = [aDecoder decodeObjectForKey:#"userKeyName"];
self.userApi = [aDecoder decodeObjectForKey:#"userApi"];
self.userCode = [aDecoder decodeObjectForKey:#"userCode"];
}
return self;
}
- (void)encodeWithCoder:(NSCoder *)enCoder {
[enCoder encodeObject:self.userKeyName forKey:#"userKeyName"];
[enCoder encodeObject:self.userApi forKey:#"userApi"];
[enCoder encodeObject:self.userCode forKey:#"userCode"];
}
#end
My preferences view controller header:
#import <Cocoa/Cocoa.h>
#import "MASPreferencesViewController.h"
#import "UserKeys.h"
#interface PreferencesApiKeysViewController : NSViewController <MASPreferencesViewController>
#property (strong) NSMutableArray *allKeys;
#end
and its implementation:
#import "PreferencesApiKeysViewController.h"
#import "UserKeys.h"
#interface PreferencesApiKeysViewController ()
#property (weak) IBOutlet NSTableView *keysTableView;
#end
#implementation PreferencesApiKeysViewController
- (id)initWithNibName:(NSString *)nibName bundle:(NSBundle *)bundle {
if ((self = [super initWithNibName:nibName bundle:bundle])) {
self.allKeys = [NSMutableArray array];
}
return self;
}
// delegating....
//
- (void)viewWillAppear {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *data = [defaults objectForKey:#"UserKeys"];
if (data != nil) {
NSArray *oldArray = [NSKeyedUnarchiver unarchiveObjectWithData:data];
if (oldArray != nil) {
self.allKeys = [[NSMutableArray alloc] initWithArray:oldArray];
} else {
self.allKeys = [NSMutableArray array];
}
}
}
- (NSView *)tableView:(NSTableView *)tableView viewForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row {
// some code...
return cellView;
}
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView {
return [self.allKeys count];
}
The error I'm getting is:
-[UserKeys count]: unrecognized selector sent to instance 0x100534df0
When I put a breakpoint in - (void)viewWillAppear, I can see that data has around 250 bytes, but this oldArray seems to be empty. I understand that I'm doing some major mistake here with self.allKeys so that my table is not aware how many rows it should create, but after lots of attempts to get proper data, I'm really out of ideas why is this happening.
So, how to properly unarchive my data and present it in NSTableView?
(I'm using Xcode 4.6)
It is because the object you appear to be dearchiving is a pointer to an object of class UserKeys, rather than an object that is or descends from NSArray. When -initWithAray: hits your oldArray pointer to UserKeys, it doesn't know, or doesn't care what class it is, it simply sends it a -count message so as to ascertain the size it must grow to.
I have a class which has it's delegate:
#protocol SNIRCControllerDelegate
- (void) serverTalked:(id)data;
#end
#interface SNIRCController : NSObject <NSStreamDelegate> {
id<SNIRCControllerDelegate> delegate;
}
- (void) setDelegate:(id<SNIRCControllerDelegate>)_delegate;
- (void) test;
#end
The implementation:
#implementation SNIRCController
- (void) setDelegate:(id<SNIRCControllerDelegate>)_delegate {
_delegate = delegate;
}
- (void) test {
[delegate serverTalked:#"test"];
}
But for some reason [delegate serverTalked:#"test"]; doesn't calls the delegate :/
This is how I do it on the AppDelegate:
#interface AppDelegate : NSObject <NSApplicationDelegate, NSStreamDelegate, SNIRCControllerDelegate> {
IBOutlet NSTextView *logField;
SNIRCController *ircController;
}
#property (assign) IBOutlet NSWindow *window;
-(void)writeToLog:(NSString*)data;
#end
#implementation AppDelegate
#synthesize window = _window;
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
ircController = [[SNIRCController alloc] init];
[ircController setDelegate:self];
[ircController test];
}
- (void) serverTalked:(id)data {
NSLog(#"got called :D");
}
-(void)writeToLog:(NSString*)data {
NSAttributedString *stringToAppend = [[NSAttributedString alloc] initWithString:[NSString stringWithFormat:#"%#\n", data]];
[[logField textStorage] appendAttributedString:stringToAppend];
}
But serverTalked: doesn't gets called :( what I'm doing wrong?
In your implementation of setDelegate:, this:
_delegate = delegate;
should be:
delegate = _delegate;
You got confused and swapped ivar and parameter. The confusion might have been caused by the fact that the underscore prefix is more commonly used for ivars. In your case, it is the parameter that is prefixed with an underscore.