Add -[NSDictionary safeObjectForKey:]

LarryLee · Oct 16, 2012 · 6ff11e7 · 6ff11e7
1 parent f811900
commit 6ff11e7
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Showing 2 changed files with 25 additions and 0 deletions.
diff --git a/SSToolkit/NSDictionary+SSToolkitAdditions.h b/SSToolkit/NSDictionary+SSToolkitAdditions.h
@@ -37,6 +37,7 @@
  */
 - (NSString *)stringWithFormEncodedComponents;
 
+
 ///--------------------------
 /// @name Deriving New Arrays
 ///--------------------------
@@ -52,6 +53,7 @@
  */
 - (NSMutableDictionary *)deepMutableCopy NS_RETURNS_RETAINED;
 
+
 ///--------------
 /// @name Hashing
 ///--------------
@@ -76,4 +78,18 @@
  */
 - (NSString *)SHA1Sum;
 
+
+///------------------------
+/// @name Accessing Objects
+///------------------------
+
+/**
+ Returns the object for the specified key or `nil` if the value is `[NSNull null]`.
+ 
+ @param key The key used to look up the object in the receiver.
+ 
+ @return The object for the specified key or `nil` if the value is `[NSNull null]`.
+ */
+- (id)safeObjectForKey:(id)key;
+
 @end
diff --git a/SSToolkit/NSDictionary+SSToolkitAdditions.m b/SSToolkit/NSDictionary+SSToolkitAdditions.m
@@ -77,6 +77,15 @@ - (NSString *)SHA1Sum {
 	return [[self _prehashData] SHA1Sum];
 }
 
+
+- (id)safeObjectForKey:(id)key {
+	id value = [self valueForKey:key];
+	if (value == [NSNull null]) {
+		return nil;
+	}
+	return value;
+}
+
 @end