Support limited "custom logging" from the iOS SDK

Summary: Add support for very specific event logging in the iOS SDK.  Single events, now from FriendPicker launch and PlacePicker launch, get sent to the server.  Underlying support for apps that are not FB auth'd as well.

Test Plan: Tested via HelloFacebook

Reviewers: jacl, clang

Reviewed By: jacl

CC: msdkexp@

Differential Revision: https://phabricator.fb.com/D583180

src/FBFriendPickerViewController.m

@@ -230,6 +230,8 @@ - (void)viewDidLoad
     self.tableView.delegate = self.selectionManager;
     [self.dataSource bindTableView:self.tableView];
     self.loader.tableView = self.tableView;
+
+    [FBUtility logInsightsEvent:@"_friendPickerLaunch" session:_session];
 }
 
 - (void)viewDidUnload {

src/FBPlacePickerViewController.m

@@ -298,6 +298,8 @@ - (void)viewDidLoad
     self.tableView.delegate = self.selectionManager;
     [self.dataSource bindTableView:self.tableView];
     self.loader.tableView = self.tableView;
+
+    [FBUtility logInsightsEvent:@"_placePickerLaunch" session:_session];
 }
 
 - (void)viewDidUnload

src/FBUtility.h

@@ -17,6 +17,8 @@
 #import <Foundation/Foundation.h>
 #import <UIKit/UIKit.h>
 
+@class FBSession;
+
 @protocol FBGraphObject;
 
 @interface FBUtility : NSObject
@@ -38,6 +40,9 @@
                         withDefault:(NSString *)value
                            inBundle:(NSBundle *)bundle;
 
++ (void)logInsightsEvent:(NSString *)eventName
+                 session:(FBSession *)session;
+
 @end
 
 #define FBConditionalLog(condition, desc, ...) \

src/FBUtility.m

@@ -15,12 +15,22 @@
  */
 
 #import "FBUtility.h"
+#import "FBGraphObject.h"
+#import "FBRequest.h"
+#import "FBSBJSON.h"
 #import "FBSession.h"
 #include <sys/time.h>
-#import "FBGraphObject.h"
 
 @implementation FBUtility
 
+typedef enum {
+    AttributionIDSendNotChecked,
+    AttributionIDSendAllowed,
+    AttributionIDSendDisallowed
+} AttributionIDSendStatus;
+
+static AttributionIDSendStatus g_attributionIDSendStatus = AttributionIDSendNotChecked;
+
 // finishes the parsing job that NSURL starts
 + (NSDictionary*)dictionaryByParsingURLQueryPart:(NSString *)encodedString {
 
@@ -143,4 +153,98 @@ + (NSString *)localizedStringForKey:(NSString *)key
     return result;
 }
 
++ (void)logInsightsEvent:(NSString *)eventName
+                 session:(FBSession *)session {
+
+    NSString *appID = [FBSession defaultAppID];
+    if (!appID) {
+        return;
+    }
+
+    // Need to check whether attribution send is needed or allowed.
+    if (session || g_attributionIDSendStatus != AttributionIDSendNotChecked) {
+
+        // Have the information we need, send immediately.
+        [self sendInsightsEvent:eventName session:session];
+
+    } else {
+
+
+        NSString *pingPath = [NSString stringWithFormat:@"%@?fields=supports_attribution", appID, nil];
+        FBRequest *pingRequest = [[[FBRequest alloc] initWithSession:nil graphPath:pingPath] autorelease];
+
+        [pingRequest startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
+
+            @try {
+
+                if (!error &&
+                    [result respondsToSelector:@selector(objectForKey:)] &&
+                    [[result objectForKey:@"supports_attribution"] boolValue]) {
+
+                    g_attributionIDSendStatus = AttributionIDSendAllowed;
+
+                } else {
+
+                    // Any error or malformed response winds up here.
+                    g_attributionIDSendStatus = AttributionIDSendDisallowed;
+
+                }
+
+                [self sendInsightsEvent:eventName session:session];
+
+            } @catch (NSException *blockException) {
+
+                NSLog(@"Failure during logInsightsEvent ping callback: '%@'", blockException.reason);
+
+            }
+         }
+        ];
+    }
+}
+
++ (void)sendInsightsEvent:(NSString *)eventName
+                  session:(FBSession *)session {
+
+    @try {
+
+        NSString *graphPath = [NSString stringWithFormat:@"%@/activities", [FBSession defaultAppID]];
+
+        NSString *attributionID = @"";
+        if (g_attributionIDSendStatus == AttributionIDSendAllowed) {
+            attributionID = [[UIPasteboard pasteboardWithName:@"fb_app_attribution" create:NO] string] ?: @"";
+        }
+
+        NSArray *customEvents = @[
+          @{ @"_eventName" : eventName }
+        ];
+
+        NSError *myError = nil;
+        FBSBJSON *writer = [[FBSBJSON alloc] init];
+        NSString *customEventsJSON = [writer stringWithFragment:customEvents error:&myError];
+        FBConditionalLog(!myError, @"Shouldn't get a JSON encoding error");
+        [writer release];
+
+        NSDictionary *postParameters =
+            @{
+               @"event" : @"CUSTOM_APP_EVENTS",
+               @"attribution": attributionID,
+               @"custom_events" : customEventsJSON,
+             };
+
+        FBRequest *request = [[[FBRequest alloc] initWithSession:session
+                                                       graphPath:graphPath
+                                                      parameters:postParameters
+                                                      HTTPMethod:@"POST"] autorelease];
+
+        // Fire and forget
+        [request startWithCompletionHandler:nil];
+
+    } @catch (NSException *exception) {
+
+        NSLog(@"Failure during sendInsightsEvent: '%@'", exception.reason);
+
+    }
+}
+
+
 @end