[ios-sdk] Update NSDate serialization to support new "Events Timezone…

…" platform migration.

Summary:
{VFU} The "Events Timezone" platform migration changes the date/time formats accepted and returned
by the Graph API. We can no longer serialize them as Unix timestamps, and must put them in ISO-8601
format instead. Older apps that are not in this migration can work around this change by explicitly
serializing dates as timestamps themselves, and sending them as strings.

Test Plan:
- Migrated unit test app into "Events Timezone" migration
- Ran unit tests

Revert Plan:

Reviewers: jacl, mmarucheck, gregschechte, ayden

Reviewed By: mmarucheck

CC: msdkexp@, platform-diffs@lists

Differential Revision: https://phabricator.fb.com/D543336

src/FBRequestConnection.m

@@ -865,8 +865,15 @@ + (void)processGraphObjectPropertyKey:(NSString*)key
         // Just serialize these.
         action(key, value);
     } else if ([value isKindOfClass:[NSDate class]]) {
-        // We have two options for serializing dates. This is the easy one.
-        value = [NSString stringWithFormat:@"%.0f", [value timeIntervalSince1970]];
+        // The "Events Timezone" platform migration affects what date/time formats Facebook accepts and returns.
+        // Apps created after 8/1/12 (or apps that have explicitly enabled the migration) should send/receive
+        // dates in ISO-8601 format. Pre-migration apps can send as Unix timestamps. Since the future is ISO-8601,
+        // that is what we support here. Apps that need pre-migration behavior can explicitly send these as
+        // integer timestamps rather than NSDates.
+        NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
+        [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZ"];
+
+        value = [dateFormatter stringFromDate:value];
         action(key, value);
     } else if ([value isKindOfClass:[NSArray class]]) {
         // Arrays are serialized as multiple elements with keys of the

src/tests/FBGraphObjectTests.m

@@ -298,14 +298,14 @@ - (void)testCommentRoundTrip
     [comment setObject:commentMessage forKey:@"message"];
 
     id comment1 = [self postComment:comment toStatusID:statusID];
+    NSString *comment1ID = [[[comment1 objectForKey:@"id"] retain] autorelease];
+    NSString *comment1Message = [[[comment1 objectForKey:@"message"] retain] autorelease];
 
     // Try posting the same comment to the same status update. We need to clear its ID first.
     [comment1 removeObjectForKey:@"id"];
     id comment2 = [self postComment:comment1 toStatusID:statusID];
 
-    NSString *comment1ID = [comment1 objectForKey:@"id"];
     NSString *comment2ID = [comment2 objectForKey:@"id"];
-    NSString *comment1Message = [comment1 objectForKey:@"message"];
     NSString *comment2Message = [comment2 objectForKey:@"message"];
 
     STAssertFalse([comment1ID isEqualToString:comment2ID], @"ended up with the same comment");
@@ -315,16 +315,15 @@ - (void)testCommentRoundTrip
 - (id)postEvent
 {
     id<FBGraphObject> event = [FBGraphObject graphObject];
-    [event setObject:[NSString stringWithFormat:@"My event on %@", [NSDate date]]
+    NSDate *startTime = [NSDate dateWithTimeIntervalSinceNow:24 * 3600];
+    [event setObject:[NSString stringWithFormat:@"My event on %@", startTime]
               forKey:@"name"];
     [event setObject:@"This is a great event. You should all come."
               forKey:@"description"];
-    NSDate *startTime = [NSDate dateWithTimeIntervalSinceNow:24 * 3600];
     NSDate *endTime = [NSDate dateWithTimeInterval:3600 sinceDate:startTime];
     [event setObject:startTime forKey:@"start_time"];
     [event setObject:endTime forKey:@"end_time"];
     [event setObject:@"My house" forKey:@"location"];
-    [event setObject:@"CLOSED" forKey:@"privacy"];
 
     return [self batchedPostAndGetWithSession:self.defaultTestSession
                                     graphPath:@"me/events"

src/tests/FBTests.m

@@ -250,15 +250,9 @@ - (id)batchedPostAndGetWithSession:(FBSession*)session
      }
             batchEntryName:@"postRequest"];
 
-    // Get the thing. We know this is being used mostly for round-tripping objects, including
-    // things with timestamps, so request Unix timestamp format so we don't need to worry about
-    // date parsing just to test other functionality..
-    NSDictionary *parameters = [NSDictionary dictionaryWithObjectsAndKeys:
-                                @"U", @"date_format", 
-                                nil];
     FBRequest *getRequest = [[FBRequest alloc] initWithSession:session 
                                                      graphPath:@"{result=postRequest:$.id}"
-                                                     parameters:parameters
+                                                     parameters:nil
                                                      HTTPMethod:nil];
     __block id createdObject = nil;
     __block FBTestBlocker *blocker = [[FBTestBlocker alloc] init];