Objective-C class category to print out names of all selectors on a class.

NSObject+DumpClassInfo.h

//
//  NSObject+DumpClassInfo.h
//  DumpSelectors
//
//  Created by Bennett Smith on 1/14/12.
//  Copyright (c) 2012 iDevelopSoftware, Inc. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NSObject (DumpClassInfo)

- (void)dumpClassInfo;

@end

NSObject+DumpClassInfo.m

//
//  NSObject+DumpClassInfo.m
//  DumpSelectors
//
//  Created by Bennett Smith on 1/14/12.
//  Copyright (c) 2012 iDevelopSoftware, Inc. All rights reserved.
//

#import "NSObject+DumpClassInfo.h"
#import <objc/runtime.h>

static void dumpClassInfo(Class c, int inheritanceDepth)
{
    Class superClass = class_getSuperclass(c);
    if (superClass != Nil)
    {
        dumpClassInfo(superClass, (inheritanceDepth + 1));
    }
    
    int i = 0;
    unsigned int mc = 0;
    
    const char* className = class_getName(c);
    
    Method* mlist = class_copyMethodList(c, &mc);
    for (i = 0; i < mc; i++)
    {
        Method method = mlist[i];
        SEL methodSelector = method_getName(method);
        const char* methodName = sel_getName(methodSelector);
        
        const char *typeEncodings = method_getTypeEncoding(method);
        
        char returnType[80];
        method_getReturnType(method, returnType, 80);
        
        NSLog(@"%2.2d %s ==> %s (%s)", inheritanceDepth, className, methodName, (typeEncodings == Nil) ? "" : typeEncodings);
        
        int ac = method_getNumberOfArguments(method);
        int a = 0;
        for (a = 0; a < ac; a++) {
            char argumentType[80];
            method_getArgumentType(method, a, argumentType, 80);
            NSLog(@"   Argument no #%d: %s", a, argumentType);
        }
    }        
}

@implementation NSObject (DumpClassInfo)

- (void)dumpClassInfo
{
    Class c =  object_getClass(self);
    dumpClassInfo(c, 0);
}

@end

The purpose of this class category is to easily print out the names of all selectors for a given Objective-C object. It is implemented as a class category on NSObject. To use this first add NSObject+DumpClassInfo.h and NSObject+DumpClassInfo.m to your project. Then make sure you #import "NSObject+DumpClassInfo.h" in your project. Finally, write a line of code like this:

[self dumpClassInfo];

and it will display a list of all method selectors for this class. Replace self with a different object id to print method selectors for another object.

method_getReturnType provides a single character "@" for objects. Any idea how to obtain the class of the object?