fix KVOBlocks

shaojiankui · Mar 27, 2018 · f84d28e · f84d28e
1 parent ed8de9d
commit f84d28e
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Showing 2 changed files with 52 additions and 4 deletions.
diff --git a/JKCategories/Foundation/NSObject/NSObject+JKKVOBlocks.h b/JKCategories/Foundation/NSObject/NSObject+JKKVOBlocks.h
@@ -24,25 +24,71 @@
 
 // This class is based on NSObject+KVOBlocks (MIT licensed) by Stephan Leroux.
 // See here: https://github.com/sleroux/KVO-Blocks
+
+
+/*
+UIViewController *observer = self;
+if (self.observersOn) {
+    // This is where the magic happens
+    [self.user jk_addObserver:observer forKeyPath:@"email" options:0 context:nil withBlock:^(NSDictionary *change, void *context) {
+        NSLog(@"Changed email");
+    }];
+    
+    [self.user jk_addObserver:observer forKeyPath:@"username" options:0 context:nil withBlock:^(NSDictionary *change, void *context) {
+        NSLog(@"Changed username");
+    }];
+} else {
+    [self.user jk_removeBlockObserver:observer forKeyPath:@"username"];
+    [self.user jk_removeBlockObserver:observer forKeyPath:@"email"];
+}
+ */
+
+
 #import <Foundation/Foundation.h>
 typedef void (^JKKVOBlock)(NSDictionary *change, void *context);
 
 @interface NSObject (JKKVOBlocks)
-
+/**
+ 添加观察者与监听属性
+ 
+ @param observer 观察者,一般为其他对象(谁想监听)
+ @param keyPath 监听的属性
+ @param options 监听模式
+ @param context context
+ @param block  监听回调
+ */
 - (void)jk_addObserver:(NSObject *)observer
          forKeyPath:(NSString *)keyPath
             options:(NSKeyValueObservingOptions)options
             context:(void *)context
           withBlock:(JKKVOBlock)block;
+/**
+ 移除观察者对属性的监听
 
+ @param observer 观察者,一般为其他对象(谁想监听)
+ @param keyPath 监听的属性
+ */
 -(void)jk_removeBlockObserver:(NSObject *)observer
                 forKeyPath:(NSString *)keyPath;
 
+/**
+ 对象本身作为观察者
+
+ @param keyPath 监听的属性
+ @param options 监听模式
+ @param context context
+ @param block 监听回调
+ */
 -(void)jk_addObserverForKeyPath:(NSString *)keyPath
                      options:(NSKeyValueObservingOptions)options
                      context:(void *)context
                    withBlock:(JKKVOBlock)block;
 
+/**
+ 移除观察者对属性的监听
+
+ @param keyPath 监听的属性
+ */
 -(void)jk_removeBlockObserverForKeyPath:(NSString *)keyPath;
 
 @end
diff --git a/JKCategories/Foundation/NSObject/NSObject+JKKVOBlocks.m b/JKCategories/Foundation/NSObject/NSObject+JKKVOBlocks.m
@@ -46,13 +46,15 @@ -(void)jk_removeBlockObserver:(NSObject *)observer
     [self removeObserver:observer forKeyPath:keyPath];
 }
 
--(void)jk_observeValueForKeyPath:(NSString *)keyPath
+-(void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context {
 
     JKKVOBlock block = objc_getAssociatedObject(self, (__bridge const void *)(keyPath));
-    block(change, context);
+    if (block) {
+        block(change, context);
+    }
 }
 
 -(void)jk_addObserverForKeyPath:(NSString *)keyPath
@@ -67,4 +69,4 @@ -(void)jk_removeBlockObserverForKeyPath:(NSString *)keyPath {
     [self jk_removeBlockObserver:self forKeyPath:keyPath];
 }
 
-@end
+@end