#725 adding completition block when removing image from cache, added an extra method so we don't break compatibility with older versions

SDWebImage/SDImageCache.h

@@ -127,6 +127,15 @@ typedef void(^SDWebImageQueryCompletedBlock)(UIImage *image, SDImageCacheType ca
  */
 - (void)removeImageForKey:(NSString *)key;
 
+
+/**
+ * Remove the image from memory and disk cache synchronously
+ *
+ * @param key The unique image cache key
+ * @param completionBlock An block that should be executed after the image has been removed (optional)
+ */
+- (void)removeImageForKey:(NSString *)key withCompletition:(void (^)())completion;
+
 /**
  * Remove the image from memory and optionally disk cache synchronously
  *
@@ -135,6 +144,15 @@ typedef void(^SDWebImageQueryCompletedBlock)(UIImage *image, SDImageCacheType ca
  */
 - (void)removeImageForKey:(NSString *)key fromDisk:(BOOL)fromDisk;
 
+/**
+ * Remove the image from memory and optionally disk cache synchronously
+ *
+ * @param key The unique image cache key
+ * @param fromDisk Also remove cache entry from disk if YES
+ * @param completionBlock An block that should be executed after the image has been removed (optional)
+ */
+- (void)removeImageForKey:(NSString *)key fromDisk:(BOOL)fromDisk withCompletition:(void (^)())completion;
+
 /**
  * Clear all memory cached images
  */

SDWebImage/SDImageCache.m

@@ -303,21 +303,39 @@ BOOL ImageDataHasPNGPreffix(NSData *data) {
 }
 
 - (void)removeImageForKey:(NSString *)key {
-    [self removeImageForKey:key fromDisk:YES];
+    [self removeImageForKey:key withCompletition:nil];
+}
+
+- (void)removeImageForKey:(NSString *)key withCompletition:(void (^)())completion {
+    [self removeImageForKey:key fromDisk:YES withCompletition:completion];
 }
 
 - (void)removeImageForKey:(NSString *)key fromDisk:(BOOL)fromDisk {
+    [self removeImageForKey:key fromDisk:fromDisk withCompletition:nil];
+}
+
+- (void)removeImageForKey:(NSString *)key fromDisk:(BOOL)fromDisk withCompletition:(void (^)())completion {
+    
     if (key == nil) {
         return;
     }
-
+    
     [self.memCache removeObjectForKey:key];
-
+    
     if (fromDisk) {
         dispatch_async(self.ioQueue, ^{
             [_fileManager removeItemAtPath:[self defaultCachePathForKey:key] error:nil];
+            
+            if (completion) {
+                dispatch_async(dispatch_get_main_queue(), ^{
+                    completion();
+                });
+            }
         });
+    } else if (completion){
+        completion();
     }
+    
 }
 
 - (void)setMaxMemoryCost:(NSUInteger)maxMemoryCost {