how we can fetch images from persistent storage of blackberry?
First of course you have to store the images there. I suggest you review some RIM documentation on the subject. This article is a good place to start. And it is good to know where the knowledge base is. There are also Developer videos which include one on the persistence model.
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I am developing an iOS notes app where a user can add image, text, audio and drawing notes. I want to implement iCloud synchronization between multiple devices. Out of the 3 options (key value, document storage, CloudKit) which one should I choose? I would like to implement the sharing of notes (collaboration) among users as well. I am using core data as my DB currently.
Key-value storage is out of question due do being too limited for your goal, document storage is only recommended when you need to handle and store the document as a whole. Since you are already using CoreData for local storage, it only makes sense to use regular CloudKit with it for cloud storage and sharing.
Synchronisation of CoreData and CloudKit can be tough. I am personally using a combo of RxCoreData and RxCloudKit libraries which provide some relief in synchronisation and some syntax sugar too.
A word in advance about uniqueness constraints: for CoreData, you define them based on key(s) or hash of all values, for CloudKit it is only possible (and also required) for the CKRecord key, to the best of my knowledge. So it is best to take care of it from the very start.
IMHO, CloudKit is the only opinion :)
I have a note app named marknote. And at the beginning I used iCloud document storage. It worked sometime, but not stable. The worst thing is, when and whether your documents can be synced is out of your control, instead it relies on Apple's daemon service. It becomes even worse when your documents are a little big, for instance several mega bytes.
So after fighting for some time, I changed to CloudKit. As #maxim-volgin has already pointed out, the implementation of CloudKit sync is tough, but it is reliable. And all headache just gone after switching to CloudKit.
I am currently trying to build a chat application in swift whilst using Firebase for real-time messaging. My only issue is I want users to send images, I want them to have profiles with images but I know Firebase has limited storage (or at least storage per pay tier is low for the number of connections you get)
So I would like to know how to connect up another database and make calls when needed between the two. So when and image is sent in a message, rather than Firebase storing the image, it stores a URL to the image in the other database.
I am under the impression something like AWS S3 is my best bet. any help is appreciated!
This question has been asked before and there are a number of solutions. It's kind of an 'opinion' type question but here are a few options.
View and store images in Firebase
Firebase has a 10Mb capacity, which is adequate for many images. However, if you need larger, they can be easily encoded as base64 and split into chunks.
If you want to go external:
s3 or Filepicker (Filestack) as well as Google provide some options.
Not sure of the overall requirements but obviously you can dig into CloudKit / CoreData and even Dropbox offers an API.
I have zero experience with Box but it may be an option as well.
Each option has it's own API.
In general, you would store a link in a firebase node to the image/object in question. However, the mechanics of that vary wildly as interfacing with CloudKit/CoreData will be different than say Filepicker.
With CoreData you will have to roll your own reference scheme whereas Filepicker you can have an almost direct reference to the file.
Many of these services provide a free or low cost tryouts and you can whip some code up in a manner of a few minutes to test out the functionality to see if it may meet your requirement.
If you need help encoding/decoding, see the answer to this question
Swift2 retrieving images from Firebase
Once you get rolling, if you have issues post some code in another question.
I've recently submitted my iOS Quiz app to Apple but noticed that the file size for the app is pretty big (about 150 MB). Users would need to be connected to wifi in order to download it per Apple's rules. My quiz app is set up so users are given 4 choices and shown an image and must guess the correct answer from the image shown to them. How would I minimize the file size for my app so that it isn't so large? Is there a way I can host the images on a server without losing the functionality of my app? I heard of something like Backend Services but know nothing about it. If anyone can guide me in the right direction that would be awesome, thanks!
You can check out a free back end service like Parse, it could do the trick for you, especially because you dont have a lot (besides images I guess) that'll be on the server side.
This also helped me start with using it.
Good luck :)
I'm assuming you have all the quiz data (questions and images) within your app bundle?
You can shrink it next to nothing if you move all your questions and images to a backend server and serve the questions and images (links) using simple JSON Structure.
You can build your own backend (Java/PHP/etc..) or look into using Parse.
use JPEG images whenever possible. PNGs costs more space. Do not place jpeg to xcassets, since they will be converted to PNGs. If your pictures should be transparent - it is better to use Webp or JPNG format.
You may use CloudKit to host your data in a public database. You won't need any backend knowledge to do that. This tutorial will help you understand the basics. WWDC videos covers some more, i suggest you to look at WWDC 2014, Introducing CloudKit and WWDC 2015, CloudKit Tips and Tricks.
First time asking a question on here, so please go easy if I don't provide enough info. Basically part of my iOS app allows users to take a picture which will be stored in a Core Data store. The attribute is a Transformable type, and I have created an NSManagedObject subclass which I simply use to set its image attribute to the new image provided by the user.
I know storing large files in Core Data is a bad idea, which is why I was excited when I saw the "Store in External Record File" option under the image attribute in the Core Data entity. However, my app performance says otherwise, taking several seconds on an iPhone 5 to load only a few images (which I know doesn't sound like much time, but considering how powerful the iPhone 5 is, older devices would likely take much longer with the same data).
I've looked around, and some people say that the Store in External Record File option is only applicable to the OS X environment, even though it is available in an iOS app. However, I also saw this under Apple's "What's New in iOS 5" doc (it's the next to last item under Core Data, near the end):
Managed objects support two significant new features: ordered relationships, and external storage for attribute values. If you specify that the value of a managed object attribute may be stored as an external record, Core Data heuristically decides on a per-value basis whether it should save the data directly in the database or store a URL to a separate file that it manages for you.
So my question is, who's right? Is it true that Apple made a mistake in giving this option for iOS apps, and that it actually does nothing unless you're on the Mac, or does it actually do something and I'm not configuring it the right way, or is it doing what it's supposed to do and the performance is bad anyway?
I've seen some guides explaining how to store large files (like images) as files, and save the URL to them in the Core Data store instead, but since this is essentially what this new option is doing, or maybe should be doing, I'm not sure if following these guides would even help.
I'm really sorry if this has been asked before. Normally I'd be fine with figuring this out on my own, but Core Data is totally new to me, and I'm still not sure how I managed to squeak by the initial setup. Thank you for any help you can offer!
who's right ?
the iOS docset for the NSAttributeDescription class does mention the allowsExternalBinaryDataStorage and the setAllowsExternalBinaryDataStorage: methods so there is little chance that there is a mistake from Apple.
are you doing something wrong or is slow anyway ?
You said that
The attribute is a Transformable type
But Core Data has a Binary data type. Maybe only this one is linked to the external storage capability.
if that's not it, we don't have enough info here:
How many pictures do you store ?
What are their sizes ?
Do you automatically fetch all the images ?
Also, the Apple doc states that:
Core Data heuristically decides on a per-value basis…
Did you use a migration or are you starting from scratch ?
You could have a look in your app's sandbox to see if your pictures are really saved outside of CoreData.
Hope this helps.
Good question!
Check this post:
Storing blobs in external location using built-in CoreData option
Apparently it should work. You should also try it in the simulator and inspect the application data folder to see if the folders are created as described (~/Library/Application Support/iPhone Simulator/... - you will figure out the rest of the path). Also you could inspect the sqlite file with the sqlite3 command to see if the binary data is in the database.
I haven't personally used this option as I would prefer to go for manually saving the images in a folder and store a reference to them in the database instead. This way it will be easier to create UIImage object from the file to be displayed, would have better control on what goes where and so on and so forth. Will take some extra labour though!
Hope that helps you out.
I'm a new developer. Recently, I'm developing a note app on iPhone with Evernote API. I have read many pdf, such as Document-based application.pdf, evernote-api.pdf and so on. But all these do is teach me how to sync with Evernote and how to design the document class. No one talks about local store mechanism.
I have designed a local store mechanism by myself; here it is:
Store all notebook/tag info in a plist file, such as which note in which notebook, which note has which tag, all of notebook/tag/note is represented by unique guid in plist.
Store each note content in their own file, with the note guid as their file name. That means however many notes the user creates, there will be the same number file on disk.
How about this local store mechanism? Is it good or bad? Any suggestion is welcome.
What's more, should I use Core Data (database) in my project?
And how can I sync with Evernote?
The most popular way to do it is to use CoreData framework. It makes easy way to store different values of your Data Model in sqlite file in local storage of device. Look at this tutorial from apple.
You have a valid approach. I think it's especially good, if you expect big document lengths. If you only expect short notes, you can use any of these: coredata, nsuserdefaults, basic nscoded arrays, textfiles, etc.