Fix: force date parser to use military hours

Lucas Vidal · Lucas Vidal · commit f3df53d68f74 · 2014-07-28T11:52:11.000-03:00
This fixes an issue that occurs when device is set to use am/pm hour format and trying to parse iso 8601 datetimes, on which cases it retrieves nil.
Also dateFormatter is stored in static reference to avoid multiple allocations when parsing, improving performance.
diff --git a/JSONModel/JSONModelTransformations/JSONValueTransformer.m b/JSONModel/JSONModelTransformations/JSONValueTransformer.m
@@ -26,6 +26,8 @@ extern BOOL isNull(id value)
     return NO;
 }
 
+static NSDateFormatter *_dateFormatter;
+
 @implementation JSONValueTransformer
 
 -(id)init
@@ -205,21 +207,26 @@ -(NSString*)JSONObjectFromNSURL:(NSURL*)url
 }
 
 #pragma mark - string <-> date
+- (void) initDateFormatter
+{
+    _dateFormatter = [[NSDateFormatter alloc] init];
+    [_dateFormatter setDateFormat:@"yyyy-MM-dd'T'HHmmssZZZZ"];
+    [_dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_GB"]];    //this will force to parse datetimes in military format
+}
+
 -(NSDate*)__NSDateFromNSString:(NSString*)string
 {
-    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
+    //avoid multiple allocations when parsing dates by using a static reference
+    if (!_dateFormatter) [self initDateFormatter];
     string = [string stringByReplacingOccurrencesOfString:@":" withString:@""]; // this is such an ugly code, is this the only way?
-    [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HHmmssZZZZ"];
-    
-    return [dateFormatter dateFromString: string];
+    return [_dateFormatter dateFromString: string];
 }
 
 -(NSString*)__JSONObjectFromNSDate:(NSDate*)date
 {
-    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
-    [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZ"];
-    
-    return [dateFormatter stringFromDate:date];
+    //avoid multiple allocations when parsing dates by using a static reference
+    if (!_dateFormatter) [self initDateFormatter];
+    return [_dateFormatter stringFromDate:date];
 }
 
 #pragma mark - hidden transform for empty dictionaries
