In my iOS app, I am using the Parse.com framework. When the app is launched for the first time or the user isn't signed in, the PFLogInViewController and the PFSignUpViewController will show up on the view. When the user creates his/her account, the application will automatically create the user, like always, but it will also create another variable under the user which is called isPrivate, which calls for a boolean. My question is how do I use the PFQuery to get the value of isPrivate for the currentUser?
Querying helps you find many objects matching a criteria. This doesn't really apply when you already know the object you want (the current user). You can decide whether the currentUser is private with
[PFUser.currentUser[#"isPrivate"] boolValue];
Though in this particular case, you don't actually need to keep a separate field to determine whether the user is an anonymous user (the type created by automatic users). Try:
[PFAnonymousUtils isLinkedWithUser:PFUser.currentUser];
This works for all authentication utils (PFFacebookUtils, PFTwitterUtils, and PFAnonymousUtils). isLinkedWithUser determines whether those auth systems have credentials for a particular user.
After playing around with PFObject, PFUser, and PFQuery, I found the answer to my question.
You have to create a PFQuery the queries the PFUser class, then you have to narrow the query down to only the currentUser username, then you request the value of isPrivate.
PFQuery *query= [PFUser query];
[query whereKey:#"username" equalTo:[[PFUser currentUser]username]];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error){
BOOL isPrivate = [[object objectForKey:#"isPrivate"]boolValue];
}];
Related
I was successfully able to save data (integer) to parse using swift.
var gameScore = PFObject(className:"GameScore")
gameScore["score"] = highscore
I have successfully stored in data in an objectId named "EN34LdmbSB" I found this objectId by logging into parse.com and looking it up. I have later unsuccessfully tried to use same objectId to retrieve data and it did not work. I have to 2 questions:
1) How to I retrieve this data from parse.
2) If this app is downloaded, say for example by 1000 users, then 1000 unique objectIds will be created when users save their score. How do I then look up their score using their unique objectIds?
I am new to database and Parse so please pardon my naivety. I am currently using NSUserDefaults to store my game score. I am trying to get a more secure way of storing the score data, hence using parse. Tried using KeyChain but did not get very far.
Thank you
You can easily retrieve the data using one of their method in iOS SDK:
PFQuery *query = [PFQuery queryWithClassName:#"GameScore"];
[query whereKey:#"playerName" equalTo: highscore];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// The find succeeded.
NSLog(#"Successfully retrieved %d scores.", objects.count);
// Do something with the found objects
for (PFObject *object in objects) {
NSLog(#"%#", object.objectId);
}
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
You can look it up in the tutorial they provided and it's really helpful and saving time:https://parse.com/docs/ios_guide#queries/iOS
For you second question, I don't quite get what you want to ask. Parse built the backend for you so that you don't have to create database to manage your data. I suggested you to go check what Parse truly does or you can modify it so that I can understand better.
I've scoured and still haven't found anything that quite works. Either the question/answer is too old or it simply hasn't worked for me. This is my first attempt at "my own" app. As it seems a right of passage, I'm making a checklist app. Here's what I'm looking for:
My Data Store contains 4 attributes: name, category, isChecked, isActive (more will surely follow as I expand)
When my View Controller initially loads, the NSFetchedResultsController has an NSPredicate that only retrieves the records whose attribute isActive is YES (or [NSNumber numberWithBool:YES). It then takes those records and displays them into the appropriate cells for the user. When a user clicks on a cell, the Data Store updates and changes the isChecked attribute accordingly. Everything works good to this point.
What I need to do now is to be able to remove the items (1 or more) from the list. Specifically, I need it to update the Data Store attributes isChecked and isActive to NO only if it's current isChecked attribute is YES. (I'm not looking to delete the record from the data store as they will be used to build up the database for the users future use.)
I've used, among other things:
[[[self fetchedResultsController] fetchedObjects]
setValue:[NSNumber numberWithBool:NO]
forKey:#"isChecked"];
This does actually work, it removes the checkmark(s) and updates the store accordingly. Problem is, not only am I making another request to the data store for the isActive items, it also searches the entire "Active List" that was fetched and sets each of their isChecked attributes to NO. This may not be too big of an issue for small lists, but as the list(s) expand this can be an issue.
The other problem is, if I add:
[[[self fetchedResultsController] fetchedObjects]
setValue:[NSNumber numberWithBool:NO]
forKey:#"isActive"];
It sets ALL of my list items to NO (as well as a second data store request within the same method.)
So my question is: How can I get through the list, find only the items that are checked and update only those records (set both the isChecked && isActive attributes = NO) whose isChecked attribute is YES rather than working through the entire list?
I've tried creating a separate fetchedResultsController specifically for this buttons action, and it did work (that is to say, it didn't crash) but the debugger popped out a rather large 'Serious Application Error'. I won't post the error message as it's long and most likely irrelevant to any solution.
Any assistance would be greatly appreciated. Thanks in advance and please be gentle :-].
EDIT
I have tried using a for loop, for (NSString *item in fetchedResultsController) but I get the error ...may not respond to 'countByEnumeratingWithState:objects:count'
It seems a loop of sorts is what's needed here, but again, nothing I can find is relevant or it's outdated. Again, thanks for any assistance.
Edit 2
Here is the original error I got when I ran a second separate fetchRequestController for this button/method:
An exception was caught from the delegate of NSFetchedResultsController during a call to -controllerDidChangeContent:. Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (4) must be equal to the number of rows contained in that section before the update (4), plus or minus the number of rows inserted or deleted from that section (0 inserted, 3 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out). with userInfo (null)
You can just loop over the fetchedObjects collection and change the managed objects. After changing them you'll need to reload your list (I guess you use a tableview).
I don't know what your classes are named, but in general you can just loop over the collection of managed objects and change them. Remember that you need to save your managed object context if you want to keep these changes for when the app closes.
NSArray* myCollection = [[self fetchedResultsController] fetchedObjects];
for(ActiveListData *managedObject in myCollection)
{
if(managedObject != nil && managedObject.isChecked)
{
managedObject.isChecked = NO;
managedObject.isActive = NO;
}
}
If you want to do the check on all object in the database you'll need a new method in your NSFetchedResultsController that has a predicate checking on isChecked and then loops over and edits the result collection.
You might want to post your error code as we could be able to point out what you did wrong.
Edit: If you're not familiar with using Core Data the apple documentation provides a lot of information: http://developer.apple.com/library/mac/#documentation/cocoa/Conceptual/CoreData/Articles/cdBasics.html
Thanks to #ggfela for his answer. The processes of his answer were spot on. Here is the actual code I put into my button/method, in hopes of it helping someone else in the future:
NSArray *moc = [[self fetchedResultsController] fetchedObjects];
for (ActiveListData *item in moc) {
if (item != nil && item.isChecked.boolValue == 1) {
item.isChecked = [NSNumber numberWithBool:NO];
item.isActive = [NSNumber numberWithBool:NO];
}
}
// Call to Data Store to update the list
NSError *error;
if (![self.managedObjectContext save:&error]) {
FATAL_CORE_DATA_ERROR(error);
return;
Explanation:
Load the contents of the result from calling the fetchedResultsController method into a temporary variable named moc
Use a for loop to cycle through the array of moc. ActiveListData is the NSManagedObject subclass that I created for my Core Data and is the proper place to insert the separated values/attributes from the data store. From there, it's pretty simple, I ensure that item is not nil AND that the item's attribute is the value I need.
NOTE
Core Data does not store the bool values YES and NO but rather 1 and 0, respectively but when you call or compare the values, you simply can not compare the value of item.isChecked because it is being passed back to you as a bool not as an integer. You can not simply compare item.isChecked == YES either since the #property of isChecked is an NSNumber. So, in the case of the if I put item.isChecked.boolValue as this will give me the representing integer for it's bool value, in this case I have it check for a 1 (YES). (Sorry if my explanation is wrong and/or confusing, but this is how I understand it and is the only way this code works.)
Then, setting the new values of these attributes is like you would expect when setting any other variable. The only "tricky" difference with this is that the NSManagedObject subclass sets the #property of the isChecked and isActive to an NSNumber (as mentioned earlier) so in order to send the proper values back to Core Data you use the method numberWithBool of the NSNumber class.
And just in case anyone gets confused by my FATAL_CORE_DATA_ERROR(error) call this is simply a macro that was defined inside the Prefix.pch file to handle my errors from the managedObjectContext. You can use any (or none) error handling you choose.
Thanks again #ggfela for your help!! If anyone else has any other suggestions on how this code should be applied, then please let me know!
You can use NSBatchUpdateRequest to update multiple records
Examples:
https://www.bignerdranch.com/blog/new-in-core-data-and-ios-8-batch-updating/
http://code.tutsplus.com/tutorials/ios-8-core-data-and-batch-updates--cms-22164
Currently, I have an application where a user clicks on a map and adds annotation points with certain subtitles. However, when the phone is power-cycled, all their added points are gone. I'm interested in making these annotations persistent. I've been trying to figure out how to do this with Core-Data, but after reading this tutorial here: http://www.raywenderlich.com/934/core-data-tutorial-getting-started, I'm a bit lost on where to start.
Any help would be appreciated, thanks.
If you have a core data application set up, you will only need to create an entity in the xcdatamodel file. Add attributes for whatever you may want to store.
latitude - double
longitude - double
title - NSString
etc. until you have what you want.
When you want to add an annotation, you should create a new core data object for your entity. It will look something like this
Location *newLocation = (Location *)[NSEntityDescription insertNewObjectForEntityForName:#"Location" inManagedObjectContext:self.managedObjectContext];
Location.latitude = ....
// and so on to store the information you want in its attributes;
You can set the attributes at different point if you change the values at a later point. You just need to be able to access the right object to go with the annotation. You should be able to do this by using NSFetchRequest in your managedObjectContext. You can use NSPredicate to filter the objects to the one you want. Then when you are ready to exit the app, save your context using
NSError *error = nil;
if ([managedObjectContext save:&error]) {
// handle the error;
}
which will store all the objects you've added to be used next time you open the app. You will then be able to create your annotations based on the objects in your managedObjectContext. I hope this is what you were looking for, or at least gives you an idea how to approach what you'd like to do.
What I'm trying is this:
1) Create a new manged object
2) Get it's temporary id with [myMO objectID];
3) Convert that ID to an NSURL, so I can save it for future reference:
NSManagedObjectID *moID = [myMO objectID];
NSURL *url = [moID URIRepresentation];
4) Save the managed object context
5) Some time later, fetch that object using the NSURL as ID
NSManagedObjectID *moID = [[context persistentStoreCoordinator] managedObjectIDForURIRepresentation:url];
And guess what: It does not work. I get an empty-stupid object back from
NSManagedObject *myOldMo = [context existingObjectWithID: moID error:&error];
But...as I said...the ID is temporary when creating an managed object. So it does make sense why this doesn't work at all. I must first save the context, and then I get a persistet ID. The real one. Right?
So is that the way to go?
1) Create the managed object
2) Save the context
3) Get the ID as NSURL
4) any time later, for example on your next birthday, access the managed object with the NSURL ;-)
I try to dream of NSManagedObjectID like a DB id which I can write on some yellow postIt sheet and glue on the middle of my monitor, so I refer back to it after lunch. You know... at least like in the old days where we used databases over telnet and executed SQL commands manually to query order information and stuff like that. The ID was the most important and significant thing, all the time.
But Core Data has this somewhat strange NSManagedObjectID thing.
What are your secret strategies? Do you actually recognize many use cases where you would need that NSManagedObjectID? Or is that something I could easily forget with no pain afterwards?
I'm not sure that it's such a big secret. The documentation describes the way to get permanent IDs for managed objects from the NSManagedObjectContext:
- (BOOL)obtainPermanentIDsForObjects:(NSArray *)objects error:(NSError **)error
http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/CoreDataFramework/Classes/NSManagedObjectContext_Class/NSManagedObjectContext.html#//apple_ref/occ/instm/NSManagedObjectContext/obtainPermanentIDsForObjects:error:
So I'm stumped on this one.
In Mac OS X there is an easy way to get the "Me" card (the owner of the Mac/account) from the built-in address book API.
Has anyone found a way to find out which contact (if it exists) belongs to the owner of the iPhone?
You could use the undocumented user default:
[[NSUserDefaults standardUserDefaults] objectForKey:#"SBFormattedPhoneNumber"];
and then search the address book for the card with that phone number.
Keep in mind that since the User Default is undocumented, Apple could change at any time and you may have trouble getting into the App Store.
Another approach you could take, although it is much more fragile, is to look at the device name. If the user hasn't changed it from the default "User Name's iPhone" AND they are using their real name as an iPhone, you could grab the user name from that. Again, not the best solution by any means, but it does give you something else to try.
The generally accepted answer to this question is to file a Radar with Apple for this feature and to prompt users to choose their card.
Contacts container have a me identifier property on iOS that can be accessed using container.value(forKey: "meIdentifier")
if let containers = try? CNContactStore().containers(matching: nil) {
containers.forEach { container in
if let meIdentifier = container.value(forKey: "meIdentifier") as? String {
print("Contacts:", "meIdentifier", meIdentifier)
}
}
The identifier is a legacy identifier used in the old AddressBook framework. You can still access it in CNContact:
let iOSLegacyIdentifier = contact.value(forKey: "iOSLegacyIdentifier")
There is no such API in the iPhone SDK 2.2.1 and earlier. Please file a request for it at: http://bugreport.apple.com
Edit: [Obsolete answer]
There's no API for getting the "me" card because there is no "me" card. The iPhone's contacts app has no way of marking a card as being "me", and the API reflects this.
I came up with a partial solution to this
you can get the device name as follows
NSString *ownerName = [[UIDevice currentDevice] name];
in English a device is originally called, for example, 'Joe Blogg's iPhone'
the break out the name
NSRange t = [ownerName rangeOfString:#"’s"];
if (t.location != NSNotFound) {
ownerName = [ownerName substringToIndex:t.location];
}
you can then take that name and search the contacts
CNContactStore *contactStore = [CNContactStore new];
NSPredicate *usersNamePredicate = [CNContact predicateForContactsMatchingName:usersName];
NSArray * keysToFetch = #[[CNContactFormatter descriptorForRequiredKeysForStyle:CNContactFormatterStyleFullName],CNContactPhoneNumbersKey,CNContactEmailAddressesKey,CNContactSocialProfilesKey, ];
NSArray * matchingContacts = [contactStore unifiedContactsMatchingPredicate:usersNamePredicate keysToFetch:keysToFetch error:nil];
Of course other languages differ in the device name string e.g. 'iPhone Von Johann Schmidt' so more parsing needs to be done for other languages and it only works if the user hasn't changed the name of the device in iTunes to something like "Joes phone' but it gives you a starting point
well... it gives you an array of matching items :) So if there is more than one contact with that array you just have to use pot luck and go with the first one or work thru multiple cards and take what you need from each.
I did say its a partial solution and even though it won't work for all user cases you might find it works for many of your users and reduces a little friction