Upload Facebook Photo And Auto Log User Out (Kiosk App) - ios

Question

I have an iPad app designed for use in a kiosk environment.
The user flow should be
Take Photo
Choose photo from iPad Album view
Share to Facebook and / or Twitter
Automatically log user out after image has been posted
I have the auto-logout of Twitter working properly, my issue is with the Facebook portion.
I have implemented the Graph API for internal testing, and would love to be able to post a complete story this way, but I don't think there is a way to log out from the Facebook app once the authorization and post is complete.
For a fallback, I can use the Feed Dialog and auto-logout from there, but as far as I can tell, there is no way to upload a local image for sharing to Facebook from there.
My Facebook Sharing code is as follows:
- (IBAction)facebookShare:(id)sender {
/// Package the image inside a dictionary
NSArray* image = #[#{#"url": self.mergeImages, #"user_generated": #"true"}];
// Create an object
id<FBGraphObject> object =
[FBGraphObject openGraphObjectForPostWithType:#"me/feed:photo"
title:#"a photo"
image:self.mergeImages
url:nil
description:nil];
// Create an action
id<FBOpenGraphAction> action = (id<FBOpenGraphAction>)[FBGraphObject graphObject];
// Set image on the action
[action setObject:image forKey:#"image"];
// Link the object to the action
[action setObject:object forKey:#"photo"];
// Hardcode the location based on Facebook Place ID
id<FBGraphPlace> place = (id<FBGraphPlace>)[FBGraphObject graphObject];
[place setId:#"279163865580772"]; // Singley + Mackie
[action setPlace:place];
// Check if the Facebook app is installed and we can present the share dialog
FBOpenGraphActionShareDialogParams *params = [[FBOpenGraphActionShareDialogParams alloc] init];
params.action = action;
params.actionType = #"me/feed:share";
// If the Facebook app is installed and we can present the share dialog
if([FBDialogs canPresentShareDialogWithOpenGraphActionParams:params]) {
// Show the share dialog
[FBDialogs presentShareDialogWithOpenGraphAction:action
actionType:#"photo_overlay:share"
previewPropertyName:#"photo"
handler:^(FBAppCall *call, NSDictionary *results, NSError *error) {
if(error) {
// An error occurred, we need to handle the error
// See: https://developers.facebook.com/docs/ios/errors
// NSLog([NSString stringWithFormat:#"Error publishing story: %#", error.description]);
} else {
// Success
NSLog(#"result %#", results);
}
}];
// If the Facebook app is NOT installed and we can't present the share dialog
} else {
// Put together the Feed dialog parameters
NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
#"name",
#"caption",
#"description",
#"link",
#"picture",
nil];
// Show the feed dialog
[FBWebDialogs presentFeedDialogModallyWithSession:nil
parameters:params
handler:^(FBWebDialogResult result, NSURL *resultURL, NSError *error) {
if (error) {
// An error occurred, we need to handle the error
// See: https://developers.facebook.com/docs/ios/errors
// NSLog([NSString stringWithFormat:#"Error publishing story: %#", error.description]);
} else {
if (result == FBWebDialogResultDialogNotCompleted) {
// User cancelled.
NSLog(#"User cancelled.");
} else {
// Handle the publish feed callback
NSDictionary *urlParams = [self parseURLParams:[resultURL query]];
if (![urlParams valueForKey:#"post_id"]) {
// User cancelled.
NSLog(#"User cancelled.");
} else {
// User clicked the Share button
NSString *result = [NSString stringWithFormat: #"Posted story, id: %#", [urlParams valueForKey:#"post_id"]];
NSLog(#"result %#", result);
}
}
}
// Auto log the user out
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSLog(#"defaults fbDidLogout ........%#",defaults);
if ([defaults objectForKey:#"FBAccessTokenKey"])
{
[defaults removeObjectForKey:#"FBAccessTokenKey"];
[defaults removeObjectForKey:#"FBExpirationDateKey"];
[defaults synchronize];
}
NSHTTPCookie *cookie;
NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
for (cookie in [storage cookies])
{
NSString* domainName = [cookie domain];
NSRange domainRange = [domainName rangeOfString:#"facebook"];
if(domainRange.length > 0)
{
[storage deleteCookie:cookie];
}
}
[FBSession.activeSession closeAndClearTokenInformation];
}];
}
}
// A function for parsing URL parameters.
- (NSDictionary*)parseURLParams:(NSString *)query {
NSArray *pairs = [query componentsSeparatedByString:#"&"];
NSMutableDictionary *params = [[NSMutableDictionary alloc] init];
for (NSString *pair in pairs) {
NSArray *kv = [pair componentsSeparatedByString:#"="];
NSString *val =
[kv[1] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
params[kv[0]] = val;
}
return params;
}
I have searched Stack Overflow far and wide for an answer to this, but have found no solutions.

Answer 1

I was finally able to figure this out! Posting the answer here to hopefully benefit others who are in the same situation.
First, add the following to your AppDelegate.m:
-(BOOL) application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation {
return [FBAppCall handleOpenURL:url sourceApplication:sourceApplication fallbackHandler:^(FBAppCall *call) {
// Facebook SDK * App Linking *
// For simplicity, this sample will ignore the link if the session is already
// open but a more advanced app could support features like user switching.
if (call.accessTokenData) {
if ([FBSession activeSession].isOpen) {
NSLog(#"INFO: Ignoring app link because current session is open.");
}
else {
[self handleAppLink:call.accessTokenData];
}
}
}];
}
// Helper method to wrap logic for handling app links.
- (void)handleAppLink:(FBAccessTokenData *)appLinkToken {
// Initialize a new blank session instance...
FBSession *appLinkSession = [[FBSession alloc] initWithAppID:nil
permissions:nil
defaultAudience:FBSessionDefaultAudienceNone
urlSchemeSuffix:nil
tokenCacheStrategy:[FBSessionTokenCachingStrategy nullCacheInstance] ];
[FBSession setActiveSession:appLinkSession];
// ... and open it from the App Link's Token.
[appLinkSession openFromAccessTokenData:appLinkToken
completionHandler:^(FBSession *session, FBSessionState status, NSError *error) {
// Forward any errors to the FBLoginView delegate.
if (error) {
//[self.loginViewController loginView:nil handleError:error];
}
}];
}
Wherever you are calling the posting action in your app, add this line to your header file:
#property (strong, nonatomic) FBRequestConnection *requestConnection;
And the following to your implementation file:
#synthesize requestConnection;
- (IBAction)facebookShare:(id)sender {
NSArray *permissions = [[NSArray alloc] initWithObjects:
#"publish_actions", #"publish_checkins", nil];
UIImage *img = self.facebookImage;
[FBSession openActiveSessionWithPublishPermissions:permissions
defaultAudience:FBSessionDefaultAudienceEveryone allowLoginUI:YES
completionHandler:^(FBSession *session,FBSessionState s, NSError *error) {
[FBSession setActiveSession:session];
if (!error) {
// Now have the permission
[self processPostingImage:img WithMessage:#"Enter_your_message_here"];
} else {
// Facebook SDK * error handling *
// if the operation is not user cancelled
if (error.fberrorCategory != FBErrorCategoryUserCancelled) {
[self presentAlertForError:error];
}
}
}];
}
-(void)logout {
[FBSession.activeSession closeAndClearTokenInformation];
[FBSession.activeSession close];
[FBSession setActiveSession:nil];
}
- (void)processPostingImage:(UIImage *) img WithMessage:(NSString *)message {
FBRequestConnection *newConnection = [[FBRequestConnection alloc] init];
FBRequestHandler handler =
^(FBRequestConnection *connection, id result, NSError *error) {
// output the results of the request
[self requestCompleted:connection forFbID:#"me" result:result error:error];
};
FBRequest *request=[[FBRequest alloc] initWithSession:FBSession.activeSession graphPath:#"me/photos" parameters:[NSDictionary dictionaryWithObjectsAndKeys:UIImageJPEGRepresentation(img, 0.7),#"source",message,#"message",#"{'value':'EVERYONE'}",#"privacy", nil] HTTPMethod:#"POST"];
[newConnection addRequest:request completionHandler:handler];
[self.requestConnection cancel];
self.requestConnection = newConnection;
[newConnection start];
}
// FBSample logic
// Report any results. Invoked once for each request we make.
- (void)requestCompleted:(FBRequestConnection *)connection
forFbID:fbID
result:(id)result
error:(NSError *)error
{
// not the completion we were looking for...
if (self.requestConnection &&
connection != self.requestConnection)
{
return;
}
// clean this up, for posterity
self.requestConnection = nil;
if (error)
{
}
else
{
[self logout];
};
}
- (void) presentAlertForError:(NSError *)error {
// Facebook SDK * error handling *
// Error handling is an important part of providing a good user experience.
// When fberrorShouldNotifyUser is YES, a fberrorUserMessage can be
// presented as a user-ready message
if (error.fberrorShouldNotifyUser) {
// The SDK has a message for the user, surface it.
[[[UIAlertView alloc] initWithTitle:#"Something Went Wrong"
message:error.fberrorUserMessage
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil] show];
} else {
}
}
Note:
To make this work with auto-logout, you also have to disable Safari on the device. This can be done by going to Settings > General > Restrictions > Allow Safari > Off. Once that is turned off, the Facebook IBAction will popup a UIWebView inside the app itself. When tapped, the current user can enter their Facebook credentials, then the app will post the image, and log the user out so the next user can use the app without having access to the previous user's Facebook details.