Update sample code for 2 chapter

chapter_2/item_10.txt

@@ -1,42 +1,50 @@
 // Item 10
 
-// C early binding
-#import <stdio.h>
-
-void printHello() {
-   printf("Hello, world!\n");
+- (void)askUserAQuestion {
+    UIAlertView *alert = [[UIAlertView alloc]
+                          initWithTitle:@"Question" message:@"What do you want to do?"
+                          delegate:self
+                          cancelButtonTitle:@"Cancel"
+                          otherButtonTitles:@"Continue",
+                          nil];
+    [alert show];
 }
-void printGoodbye() {
-    printf("Goodbye, world!\n");
-} 
 
-void doTheThing(int type) {
-    if (type == 0) {
-        printHello();
+- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
+    if (buttonIndex == 0) {
+        [self doCancel];
     } else {
-        printGoodbye();
+        [self doContinue];
     }
-    return 0;
 }
 
+#import <objc/runtime.h>
 
-// C late binding
-#import <stdio.h>
+static void *EOCMyAlertViewKey = "EOCMyAlertViewKey";
 
-void printHello() {
-   printf("Hello, world!\n");
+- (void)askUserAQuestion {
+    UIAlertView *alert = [[UIAlertView alloc]
+                          initWithTitle:@"Question" message:@"What do you want to do?"
+                          delegate:self
+                          cancelButtonTitle:@"Cancel"
+                          otherButtonTitles:@"Continue",
+                          nil];
+    void (^block)(NSInteger) = ^(NSInteger buttonIndex){
+        if (buttonIndex == 0) {
+            [self doCancel];
+        } else {
+            [self doContinue];
+        }
+    };
+
+    objc_setAssociatedObject(alert,
+                             EOCMyAlertViewKey,
+                             block,
+                             OBJC_ASSOCIATION_COPY);
+    [alert show];
 }
-void printGoodbye() {
-    printf("Goodbye, world!\n");
-} 
 
-void doTheThing(int type) {
-    void (*fnc)();
-    if (type == 0) {
-        fnc = printHello;
-    } else {
-        fnc = printGoodbye;
-    }
-    fnc();
-    return 0;
-}
+- (void)alertView:(UIAlertView*)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
+    void (^block)(NSInteger) = objc_getAssociatedObject(alertView, EOCMyAlertViewKey);
+    block(buttonIndex);
+}

chapter_2/item_11.txt

@@ -1,106 +1,42 @@
 // Item 11
 
-// `resolveInstanceMethod' example
-id autoDictionaryGetter(id self, SEL _cmd);
-void autoDictionarySetter(id self, SEL _cmd, id value);
+// C early binding
+#import <stdio.h>
 
-+ (BOOL)resolveInstanceMethod:(SEL)selector {
-    NSString *selectorString = NSStringFromSelector(selector);
-    if (/* selector is from a @dynamic property */) {
-        if ([selectorString hasPrefix:@"set"]) {
-            class_addMethod(self, selector, (IMP)autoDictionarySetter, "v@:@");
-        } else {
-            class_addMethod(self, selector, (IMP)autoDictionaryGetter, "@@:");
-        }
-        return YES;
-    }
-    return [super resolveInstanceMethod:selector];
-}
-
-
-// Full "AutoDictionary" example
-#import <Foundation/Foundation.h>
-
-@interface AutoDictionary : NSObject
-@property (nonatomic, strong) NSString *string;
-@property (nonatomic, strong) NSNumber *number;
-@property (nonatomic, strong) NSDate *date;
-@property (nonatomic, strong) id opaqueObject;
-@end
-
-#import "AutoDictionary.h"
-#import <objc/runtime.h>
-
-id autoDictionaryGetter(id self, SEL _cmd) {
-    // Get the backing store from the object
-    AutoDictionary *typedSelf = (AutoDictionary*)self;
-    NSMutableDictionary *backingStore = typedSelf.backingStore;
-
-    // The key is simply the selector name
-    NSString *key = NSStringFromSelector(_cmd);
-
-    // Return the value
-    return [backingStore objectForKey:key];
+void printHello() {
+   printf("Hello, world!\n");
 }
+void printGoodbye() {
+    printf("Goodbye, world!\n");
+} 
 
-void autoDictionarySetter(id self, SEL _cmd, id value) {
-    // Get the backing store from the object
-    AutoDictionary *typedSelf = (AutoDictionary*)self;
-    NSMutableDictionary *backingStore = typedSelf.backingStore;
-
-    /** The selector will be for example, "setOpaqueObject:".
-     *  We need to remove the "set", ":" and lowercase the first
-     *  letter of the remainder.
-     */
-    NSString *selectorString = NSStringFromSelector(_cmd);
-    NSMutableString *key = [selectorString mutableCopy];
-
-    // Remove the `:' at the end
-    [key deleteCharactersInRange:NSMakeRange(key.length - 1, 1)];
-
-    // Remove the `set' prefix
-    [key deleteCharactersInRange:NSMakeRange(0, 3)];
-
-    // Lowercase the first character
-    NSString *lowercaseFirstChar = [[key substringToIndex:1] lowercaseString];
-    [key replaceCharactersInRange:NSMakeRange(0, 1) withString:lowercaseFirstChar];
-
-    if (value) {
-        [backingStore setObject:value forKey:key];
+void doTheThing(int type) {
+    if (type == 0) {
+        printHello();
     } else {
-        [backingStore removeObjectForKey:key];
+        printGoodbye();
     }
+    return 0;
 }
 
-@interface AutoDictionary ()
-@property (nonatomic, strong) NSMutableDictionary *backingStore;
-@end
 
-@implementation AutoDictionary
-@dynamic string, number, date, opaqueObject;
+// C late binding
+#import <stdio.h>
 
-- (id)init {
-    if ((self = [super init])) {
-        _backingStore = [NSMutableDictionary new];
-    }
-    return self;
+void printHello() {
+   printf("Hello, world!\n");
 }
-
-+ (BOOL)resolveInstanceMethod:(SEL)selector {
-    NSString *selectorString = NSStringFromSelector(selector);
-    if ([selectorString hasPrefix:@"set"]) {
-        class_addMethod(self, selector, (IMP)autoDictionarySetter, "v@:@");
+void printGoodbye() {
+    printf("Goodbye, world!\n");
+} 
+
+void doTheThing(int type) {
+    void (*fnc)();
+    if (type == 0) {
+        fnc = printHello;
     } else {
-        class_addMethod(self, selector, (IMP)autoDictionaryGetter, "@@:");
+        fnc = printGoodbye;
     }
-    return YES;
-}
-
-@end
-
-
-// Using AutoDictionary
-AutoDictionary *dict = [AutoDictionary new];
-dict.date = [NSDate dateWithTimeIntervalSince1970:475372800];
-NSLog(@"dict.date = %@", dict.date);
-// Output: dict.date = 1985-01-24 00:00:00 +0000
+    fnc();
+    return 0;
+}

chapter_2/item_12.txt

@@ -1,44 +1,107 @@
-// Item 12
+// Item 11
 
-// Exchanging methods
-Method originalMethod = 
-    class_getInstanceMethod([NSString class], 
-                            @selector(lowercaseString));
-Method swappedMethod = 
-    class_getInstanceMethod([NSString class], 
-                            @selector(uppercaseString));
-method_exchangeImplementations(originalMethod, swappedMethod);
+// `resolveInstanceMethod' example
+id autoDictionaryGetter(id self, SEL _cmd);
+void autoDictionarySetter(id self, SEL _cmd, id value);
 
++ (BOOL)resolveInstanceMethod:(SEL)selector {
+    NSString *selectorString = NSStringFromSelector(selector);
+    if (/* selector is from a @dynamic property */) {
+        if ([selectorString hasPrefix:@"set"]) {
+            class_addMethod(self, selector, (IMP)autoDictionarySetter, "v@:@");
+        } else {
+            class_addMethod(self, selector, (IMP)autoDictionaryGetter, "@@:");
+        }
+        return YES;
+    }
+
+    return [super resolveInstanceMethod:selector];
+}
 
-// Using the method exchanging of NSString
-NSString *string = @"ThIs iS tHe StRiNg";
 
-NSString *lowercaseString = [string lowercaseString];
-NSLog(@"lowercaseString = %@", lowercaseString);
-// Output: lowercaseString = THIS IS THE STRING
+// Full "EOCAutoDictionary" example
+#import <Foundation/Foundation.h>
 
-NSString *uppercaseString = [string uppercaseString];
-NSLog(@"uppercaseString = %@", uppercaseString);
-// Output: uppercaseString = this is the string
+@interface EOCAutoDictionary : NSObject
+@property (nonatomic, strong) NSString *string;
+@property (nonatomic, strong) NSNumber *number;
+@property (nonatomic, strong) NSDate *date;
+@property (nonatomic, strong) id opaqueObject;
+@end
 
+#import "EOCAutoDictionary.h"
+#import <objc/runtime.h>
 
-// Using a category and then swizzling methods
-@interface NSString (MyAdditions)
-- (NSString*)myLowercaseString;
+@interface EOCAutoDictionary ()
+@property (nonatomic, strong) NSMutableDictionary *backingStore;
 @end
 
-@implementation NSString (MyAdditions)
-- (NSString*)myLowercaseString {
-    NSString *lowercase = [self myLowercaseString];
-    NSLog(@"Lowercasing string: %@ => %@", self, lowercase);
-    return lowercase;
+@implementation EOCAutoDictionary
+@dynamic string, number, date, opaqueObject;
+
+- (id)init {
+    if ((self = [super init])) {
+        _backingStore = [NSMutableDictionary new];
+    }
+    return self;
+}
+
++ (BOOL)resolveInstanceMethod:(SEL)selector {
+    NSString *selectorString = NSStringFromSelector(selector);
+    if ([selectorString hasPrefix:@"set"]) {
+        class_addMethod(self, selector, (IMP)autoDictionarySetter, "v@:@");
+    } else {
+        class_addMethod(self, selector, (IMP)autoDictionaryGetter, "@@:");
+    }
+    return YES;
 }
+
 @end
 
-Method originalMethod = class_getInstanceMethod([NSString class], @selector(lowercaseString));
-Method swappedMethod = class_getInstanceMethod([NSString class], @selector(myLowercaseString));
-method_exchangeImplementations(originalMethod, swappedMethod);
+id autoDictionaryGetter(id self, SEL _cmd) {
+    // Get the backing store from the object
+    EOCAutoDictionary *typedSelf = (EOCAutoDictionary*)self;
+    NSMutableDictionary *backingStore = typedSelf.backingStore;
+
+    // The key is simply the selector name
+    NSString *key = NSStringFromSelector(_cmd);
+
+    // Return the value
+    return [backingStore objectForKey:key];
+}
+
+void autoDictionarySetter(id self, SEL _cmd, id value) {
+    // Get the backing store from the object
+    EOCAutoDictionary *typedSelf = (EOCAutoDictionary*)self;
+    NSMutableDictionary *backingStore = typedSelf.backingStore;
+
+    /** The selector will be for example, "setOpaqueObject:".
+     *  We need to remove the "set", ":" and lowercase the first
+     *  letter of the remainder.
+     */
+    NSString *selectorString = NSStringFromSelector(_cmd);
+    NSMutableString *key = [selectorString mutableCopy];
+
+    // Remove the `:' at the end
+    [key deleteCharactersInRange:NSMakeRange(key.length - 1, 1)];
+
+    // Remove the `set' prefix
+    [key deleteCharactersInRange:NSMakeRange(0, 3)];
+
+    // Lowercase the first character
+    NSString *lowercaseFirstChar = [[key substringToIndex:1] lowercaseString];
+    [key replaceCharactersInRange:NSMakeRange(0, 1) withString:lowercaseFirstChar];
+
+    if (value) {
+        [backingStore setObject:value forKey:key];
+    } else {
+        [backingStore removeObjectForKey:key];
+    }
+}
+
+// Using EOCAutoDictionary
+EOCAutoDictionary *dict = [EOCAutoDictionary new];
+dict.date = [NSDate dateWithTimeIntervalSince1970:475372800];
+NSLog(@"dict.date = %@", dict.date);
+// Output: dict.date = 1985-01-24 00:00:00 +0000
 
-NSString *string = @"ThIs iS tHe StRiNg";
-NSString *lowercaseString = [string lowercaseString];
-// Output: Lowercasing string: ThIs iS tHe StRiNg => this is the string