Calling instance method to access IBOutlet instance from another class - objective-c

Question

I've been searching through a lot of forum but it's still driving me crazy.
i don't understand how to access IBOutlet instance for example of class 'A' from class 'B' which is attempting to change the value let's say the instance type is IBOutlet NSTextLabel *progressStatus with stringValue "Capturing" want to change to "Recognizing". It can be called only from the instance method of classA it self, but not from another class.
#interface classA : NSView
{
NSTextField *progressStatus;
}
#property (assign) IBOutlet NSTextField *progressStatus;
-(void)recognizeStatus;
#end
#import "classA.h"
#implementation classA
#synthesize progressStatus;
-(void)awakeFromNib
{
[self recognizeStatus]; //successfully change the value inside progressStatus
}
-(void)recognizeStatus
{
[progressStatus setStringValue:#"Recognizing"];
NSLog(#"Progress Status : %#",progressStatus.stringValue);
}
- (void)captureOutput:(QTCaptureOutput *)captureOutput didOutputVideoFrame:(CVImageBufferRef)videoFrame withSampleBuffer:(QTSampleBuffer *)sampleBuffer fromConnection:(QTCaptureConnection*)connection
{
//code to convert videoFrame to IplImage type named frameImage
BOOL faceDetected = [classB faceDetection:frameImage];
}
#end
#import "classA.h"
#interface classB : NSObject
{
}
+(BOOL)faceDetection:(IplImage*)source;
#end
#import "classA.h"
#import "classB.h"
#implementation classB
+(BOOL)faceDetection:(IplImage*)source
{
classA *status = [[classA alloc] init];
[status recognizeStatus]; //no changes with the value inside progressStatus
//return bool type
}
#end

Answer 1

In classB's class method faceDetection:you initialize an instance of classA which derives from NSView, but you do not add the instance to the view hierarchy. Further, in initializing the instance of classA you aren't loading the view from a nib, so the instance of classA status likely has a nil progressStatus.
I suspect you may be trying to access an instance of classA that was already initialized and added to the view hierarchy elsewhere; but initializing another instance won't provide you with a reference to the original instance.