Passing data to my custom NSObject? - ios

Question

I have attempted to create my first custom class "AudioPlayer". I want to pass data (the audio title) from a tableview to my "AudioPlayer" and load the AudioPlayer with initWithContentsOfURL:[NSURL fileURLWithPath:path] but when I alloc the "AudioPlayer" in my "MainViewController" i get the error "Incompatible pointer types initializing 'Audio Player*___strong' with and expression of type AVAudioPLayer*". My question is, How would i initialize my custom audio player with the selected audio's title as the URL? It works fine when I created a variable of AVAudioPlayer, but I don't know how to pass it to my custom class.
Here is my custom class Header..
#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
#interface AudioPlayer : NSObject{
AVAudioPlayer *audioPlayer;
//Volume slider
NSTimer *volumeTimer;
IBOutlet UISlider *volumeSlider;
}
-(bool) isPlaying;
-(bool) isPaused;
-(void)playPause:(id)sender;
#property (nonatomic, retain) AVAudioPlayer *audioPlayer;
#end
Here is my custom class implementation file...
#import "AudioPlayer.h"
#implementation AudioPlayer
#synthesize audioPlayer;
-(void)playPause{
if ([audioPlayer isPlaying]) {
[audioPlayer pause];
} else {
[audioPlayer play];
}
}
-(void)volumeSlider
{
//Setup the volume slider
volumeTimer = [NSTimer scheduledTimerWithTimeInterval:0 target:self selector:#selector(updateVolumeSlider) userInfo:nil repeats:YES];
[audioPlayer setVolume:volumeSlider.value];
}
#end
Here is the MainView implementation...
- (void)viewDidLoad
{
[super viewDidLoad];
//Instantiate performanceArray
performanceArray = [[NSMutableArray alloc]initWithObjects:#"Centering", nil];
//Instantiate recoveryArray
recoveryArray = [[NSMutableArray alloc]initWithObjects:#"Power Nap", nil];
//Instantiate the AudioPlayer
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:self.tableView.indexPathForSelectedRow];
NSString *path = [[NSBundle mainBundle] pathForResource:cell.textLabel.text ofType:#"m4a"];
AudioPlayer *audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
[audioPlayer.audioPlayer prepareToPlay];
}

Answer 1

I think you are confusing your custom class with AVAudioPlayer class.
If you are trying to add more methods and options to the default class of AVAudioPlayer, you should subclass AVAudioPlayer rather than NSObject.
#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
#interface AudioPlayer : AVAudioPlayer
// the rest of your code
and then as deanandreakis answered, you need to alloc/init your class rather than AVAudioPlayer.
meaning:
AudioPlayer *audioPlayer = [[AudioPlayer alloc] init];
Or you can use categories to add your custom methods added to AVAudioPlayer.

Answer 2

Your AudioPlayer object that you created is not of type AVAudioPlayer so I think the following line:
AudioPlayer *audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
should be something like : AudioPlayer *audioPlayer = [[AudioPlayer alloc] init];
which would create an object of your custom class. You have at least a couple of options to then pass the NSURL information such as adding params to your custom classes init method or creating another property in your custom class that you set just after you create your object.
In your custom class AudioPlayer you could add a new my URL attribute:
#interface AudioPlayer : NSObject{
AVAudioPlayer *audioPlayer;
//Volume slider
NSTimer *volumeTimer;
IBOutlet UISlider *volumeSlider;
NSURL* myURL;
}
Then in your implementation file for AudioPlayer add the following init method:
-(id)initWithURL:(NSURL)theURL
{
self = [super init];
if (self) {
// perform initialization of object here
myURL = theURL;
}
return self;
}
And then in your MainView you could do something like:
NSURL* theURL = [NSURL fileURLWithPath:path];
AudioPlayer *audioPlayer = [[AudioPlayer alloc] initWithURL:theURL];