Is it possible to detect deleted Address Book entries (for example from the iOS phonebook itself) from within an application?
I have an application which needs to synchronize a local copy of the iOS Address Book database with the Address book from the phone. The application supports background mode on iOSes which support it.
Testing the application in a background capable iOS environment my problem is the following: The application does not detect an entry which has been deleted in the system address book until the application is closed completely (iOS 4 killing it with the red X in springboard). If the application is simply sent to the background, a contact is deleted from the system address book, and then the app brought to the foreground again the function ABRecordRef() for the deleted entry id does not return NULL as would be expected for an entry which no longer exists, it returns the entry as if it had never been removed from the system address book database.
As above - if the application is completely terminated and restarted then ABRecordRef() for the deleted id works as expected - it returns NULL. Is there any way to detect this deleted entry without waiting for the app to be killed and restarted?
Yes. Register for changes to the address book with ABAddressBookRegisterExternalChangeCallback, e.g.
// Your method called when the user has granted access to their address book data.
- (void)accessGrantedForAddressBook
{
ABAddressBookRegisterExternalChangeCallback(sharedAddressBook, MyAddressBookExternalChangeCallback, (__bridge void *)(self));
}
Where MyAddressBookExternalChangeCallback is your callback function.
I belive that you need to create a new ABAddressBook every time you refresh data from the address book. The reason is this:
You might have added, updated and removed records in your copy of the address book but not yet called Save or Revert. Hence, if the system (e.g. iOS build in contact book app) changes things in the address book, you cannot get them automatically.
Try either running Revert or to recreate the addressbook and it should work.
Related
Can I extend the server-side Java Code in Worklight?
For example, there is a class called JavaScriptIntegrationLibraryImplementation under com.worklight.integration.js. Inside this class, there is a method broadcastNotification and I would like to override this method. Is it possible to do so?
EDIT
The reason is that:
When I make the subscription in client side with option field (e.g. add customType: A), I would like to retrieve a list of devices which have been subscribed to this event source. Base on the option field in deviceSubscrpition, I would like to have some business logic to determine who to send the notification message. For example, I will only submit the message to the user which 'customType=A'.
However, there is no API in Worklight which can retrieve a list of devices which make me to retrieve the list first. Then do the logic in JavaScript and called WL.Server.notifyDevice..
Therefore, I would like to check whether there is any method to retrieve a list of devices (through API / Adapter which connects to DB) which have subscribed to an event source.
Thanks.
This part of Worklight is not extendable. You can try and override this method as you say, but do note this is not supported and we cannot help in this case.
Edit
Now that it is clear what you're trying to achieve... what you are looking for currently not available. I will open a feature request for it and it will get evaluated at some point (if you are a customer of IBM, I suggest to get in touch with your contact...).
My suggestion (somewhat hackish in form): you could perhaps use multiple Event Sources, where each event source represents an iOS version. On the client-side, upon app initialization, you can retrieve the iOS version and use it to register to the correct event source (this would be very generic code to allow re-use). In case a new iOS version is released (you will likely know of this in advance), you simply add this event source to the adapter code and re-deploy the adapter. Users of the new iOS version could still register for notification, because you get the iOS version upon init, and use this information to register to the correct event source...
To reiterate:
The adapter contains: ES_iOS5 ES_iOS6
The client:
fetches iOS version, stores it in some variable.
registers to event source, where event source name is ES_${iOSVersion}
if a new iOS version is released, simply create a new event source and re-deploy
the adapter; the client is already equipped to handle this.
#Red23jordon,
i had similar case, i created a custom table where at the time of subscription, I was saving
user ID and event type in custom table. and when user unsubscribe then i also remove details from custom table.
For sending push to users subscribed to a particular "even type" i look into custom table to get list of user IDs subscribed to particular event type, and then i went into Notification user/device tables and fetching corresponding devices and sending Push.
Hope it may help you.
thanks
I am new to WinRT and was playing around with session state. I am navigating to a page to collect data and then want to return to the main page. Just before navigation I am using:
SuspensionManager.SessionState["CurrentState"] = someObject;
The object contains lists of other mildly complex objects, etc... All seems to be working but is this the correct way to use the Suspension Manager?
I have looked at other posts on the topic and some people report that it is necessary to use [DataContract] and [DataMember] attributes to all the classes that are serialized. I omitted them and it still works, (getting the data across pages). So what is the recommended approach?
I may be reading too much into one aspect your question, but the role of SuspensionManager and SessionState is to store just enough information to bring your application back to the place the user left it if the application is actually terminated while it's suspended.
In the Windows 8 application lifecycle, your app gets 'suspended' if another app comes to the foreground. While your app is suspended all of its state is retained in memory, and if reactivated (you flip back to it) everything* is restored "for free".
A suspended app could, however, also be terminated by the OS (b/c of memory pressure, for instance) and there is no opportunity to react to that scenario in your app, so what you are really doing with SessionState is storing what's necessary to 'recreate' the last place the user was at IF the application had actually terminated. It's essentially an insurance policy: if the application is merely suspended, SessionState isn't really needed.
The 'what's necessary' is the grey area, I could store all of the information about say a user profile that was in progress OR I could save just the userid that indexes into my persistent storage of all the user profile data. I generally have more of a minimalist view and will retain as little as possible in SessionState - I make the analogy that I don't need to remember everything, I only need to remember how/where to get/find everything.
There's an implication as well in your question that you're using SessionState to pass information between pages in your app, and that's not really the intent. Each page of your app is typically connected with a view model, and when you interact with a page of that app, you'd update the view model and drive additional screens and experiences from the changes already in the view model. Leaving one screen of your app and returning the main one would also imply to me that you've persisted what ever information you collected - certainly to the view model, but also to something persistent like a data base or local storage. When you revisit that page, you'd then pull the data back out of your view model (or that persistent storage); the main page doesn't need that information so why hold on to it?
Lastly, since you mentioned being new to WinRT, you may want to check out App Builder, which pulls together a number of resources in consumable chunks to lead you through building an app over a period of 30-days (though all material is available, so you can consume at any pace you want :)) The discussion of lifecycle management that's germane to your question comes in on Day 17 of that sequence.
*"everything is restored for free" doesn't necessarily mean you don't have any work to do when an app comes out of the suspended state. There may be stale data that requires refreshing, and connections or other transient or short-lived entities may need to be refreshed/recreated.
I am using the latest version of the libspotify API (12.1.51). And I am coding using C# and libspotify.NET (a simple interop wrapper library for libspotify). I have built a program that creates playlists using the libspotify API. I am using the latest native Spotify client for Windows for checking my created playlists.
I have built a program that waits for a playlist name and a list of track URIs or one album URI and creates the corresponding playlist. If an album URI is supplied then all the tracks from the album will be added to the new playlist otherwise the supplied list of track URIs will be used to create the new playlist. The program waits until the callback
playlist_update_in_progress
is called and the done parameter equals true before accepting new playlists to create.
It works well except that sometimes the playlists are created with no names but do have all the tracks. I can just tell the program to create the exact same playlist that got no name and it might work the second time. It happens randomly but I have noticed that if I create about 200 playlists then maybe 5-10 playlists get no names. I can see the playlists being added in your Spotify client as the program is running and creating the playlists and randomly seeing playlists with no names. The playlists appear almost at the same time the callback is called and done equals true (not always of course, there might be a delay). I tried manually renaming the playlists in the Spotify client for Windows with no problems (the playlist name length was 0 or an empty string if you will). The native Spotify client does not even allow empty playlist names.
I use:
sp_playlistcontainer_add_new_playlist
to add a new playlist and I have tried using IntPtr and a C# string to pass to it. Tried both:
[DllImport("libspotify")]
public static extern IntPtr sp_playlistcontainer_add_new_playlist(IntPtr playlistContainerPtr, string name);
[DllImport("libspotify")]
public static extern IntPtr sp_playlistcontainer_add_new_playlist(IntPtr playlistContainerPtr, IntPtr namePtr);
And I have also tried
sp_playlist_rename
to rename the playlist several times (as some sort of fix) with no success. I do not know exactly what happens at the server when the playlists are created. Is this a bug or what is going on?
I have really tried a lot of hacks to make this work, but to no avail.
More info about the program:
First it connects to Spotify and then waits for some console input.
It checks the input for the following strings:
To create a playlist using a name and a list of tracks:
createplaylistfromtracks "Tracks playlist" spotify:track:36MuLw248uzLPtrJ6073ZR spotify:track:5WPkvx0MARhlWhXp1sJg4k spotify:track:1VrdbSFVU9wJkuDM2sWYVe spotify:track:66RG0BBwpQqHxZs06UUyeo spotify:track:0zp3uPuhnARR1XYsgg5JLV
and to create a playlist using a name and a list of tracks from an album URI:
createplaylistfromalbum "Album playlist" spotify:album:5rVwDKRKa1FjDlLofDZyRb
And then the program parses the input and creates the playlist and settings a flag Busy = true so that the console will not read any input until Busy = false, which occurs when the playlist_update_in_progress callback is called and done is true. Then it reads input again...
Any help would be highly appreciated.
We have many applications running libspotify both internally and externally and we've had no problems like this with the library, which would suggest this isn't a bug in libspotify.
A few pointers that might cause this to happen:
Make sure you're managing threads properly. When you get a notify_main_thread() call (which arrives on some background thread), you must asynchronously call sp_sesion_process_events() from the main thread, so you need to make sure you're marshalling this over to the main thread properly. If this process isn't working properly, stuff will start acting weird.
Since you're doing many operations, make sure libspotify has time to synchronise all of your changes with the service. The playlist_update_in_progress is designed to notify you when multiple mutations are happening to the playlist, and is typically useful when changes are coming in from elsewhere. Instead, playlist_state_changed is what you need for listening to changes like that (typically, after a rename, I believe the playlists goes into a "loading" state while the change is applied, then back out (that is, sp_playlist_is_loading returns false again) once it's done.
Also, when you're exiting your application, make sure you perform a sp_session_logout() call and wait until the logged_out callback is fired before exiting. If you don't, some changes might not be synchronised with the service.
I am developing a Cocoa Mac app which dynamically generates and registers itself for URL schemes. However, when the application registers itself to handle a newly generated URL scheme (e.g. myscheme1423://), I would like to prevent the application from responding to any previously registered URL schemes.
I am using LSSetDefaultHandlerForURLScheme() for the purpose of registering a URL scheme; in conjunction, the application automatically overwrites it's Info.plist to contain the new scheme. As you may know, the LSSetDefaultHandlerForURLScheme() function adds the given bundleID/scheme to a Launch Services database. However, I couldn't find an equivalent Launch Services function to remove the same bundleID/scheme pair from the database.
I know that I could simply ignore any external events which originated from a URL scheme other than the one for which the app is actively registered, but it feels to me that there should be a simple way to completely wipe out the system's knowledge of the previous scheme. If my application goes through the process of registering for a new scheme more than a few hundred times, a point will come where a significant amount of space (for a Plist, at least) is being taken up on disk by a plethora of pointless pieces of data (i.e. the old Launch Services entries).
I just fired up a playground and began playing. This is utterly undocumented but it appears to work.
Try passing ("None" as CFString) for the second parameter of
LSSetDefaultHandlerForURLScheme()
I'm working on a web application that enables users to login, only at specific locations. I'm using CLLocationManager and I initialized and called startUpdatingLocation at AppDelegate -didFinishLaunchingWithOptions. My UIWebView is supposed to pull the location at initialization to determine whether user's within the specified locations. However, at the launch of my application, [locationManager location] is always null and updates after my UIWebView is initialized and displayed therefore already sending an error message to the user.
How do I make my locationManager update its location at initialization?
Sounds like you've coded the location stuff correctly. What you are missing (but have seen) is that the update most certainly does not happen instantaneously. You need to "gate" the rest of your UI's presentation (i.e. your webview) on the location information becoming available. There are a lot of ways to do this. A common tactic is to present a full-screen "HUD" or veil with some indicator to the user that the app is initializing or locating them (with an activity indicator, too, is always a nice touch.) Behind that (out of sight to the user) you can be waiting for the location result and then kickoff the appropriate UI update, and then drop the veil.
Any of that make sense or give you some ideas? I've done this plenty of times. Synchronizing async activities (like location updates) with real-time UI updates that make sense can be challenging, but isn't impossible. :-)
You will need to account for an initial nil value in your applications UI and wait for the first location update.
-location
Discussion
The value of this property is nil if no location data has
ever been retrieved.
It is a good idea to check the timestamp of the location that is
returned. If the receiver is currently gathering location data, but
the minimum distance filter is large, the returned location might be
relatively old. If it is, you can stop the receiver and start it again
to force an update
Also you should check out Region Monitoring since you would like for you users to only be able to login at specific locations.