I'm planning a new ios app and am not sure of what is the best way to set up a start list for a tableView on first app start. The app uses Core Data (more precisely Magical Record). Should I use some kind of (p)list (dictionary) which gets imported or should I just hard code the default entries like when the user adds something through a formula? Thank you!
There are a load of arguments for and against all different ways of doing this.
Personally I prefer just to hard code all the default entries (if there aren't thousands of them obviously).
Related
I've used archiving, user defaults, and some Core Data in my apps before, but I'm running into a wall re: the best method for my current scenario. I have an app that needs to instantiate some objects from a resource file each time before it's used. An example of one of the objects could be a "MathQuestion" object that has the properties:
questionID (Int) - 2341
questionText (String) — "What is the square root of _?"
questionVariable (Float) – "4"
correctAnswer (a block/closure that returns a Float) – "{return sqrt(value)}".
Ideally, I'd just have something like a spreadsheet with columns for each of these properties and rows for each of the different questions. That way, I would really be able to visualize all the data and make quick changes during development.
My app uses Parse, which is great for visualization and easy editing of values, but for this case, I'd rather the resources remained on the device and not the Parse server. I've been considering Core Data up till this point, but (this could be my inexperience with C.D.), I'm unaware of any way to manually edit the data—and it seems like it may be overkill for what I'm looking for anyways. (I basically just need a way to upload and parse a CSV!) Any advice would be welcome!
I would still recommend Core Data. It is simply the most efficient and scalable mechanism to store and retrieve data.
When I work in your kind of scenario, what I often do is work with a spreadsheet where I can conveniently edit the data. You could edit a CSV version of it that you have included in your target. (If this does not work for you, you could also copy paste into a separate CSV file right into Xcode.)
On every start, you just trash the data store (using NSFileManager when creating the NSPersistentStoreCoordinator). Then you call a method that reads in the CSV and stores it in Core Data.
Once you are done with development, you simply keep the sqlite file (you can include it in the bundle and copy it over, or re-generate it from your CSV the first time the app runs).
I'm building a small social network. I quite far already. But now I need to implement a caching system.
In my app I can like things and follow other peoples. So what I want:
When I like a recipe it automatically counts up the number of likes. In the whole app without to reload a page
When I follow someone the it aitmomatically counts up the number of followers. In the whole app aswell without reloading anything.
Does anybody have an idea how to do this?
I'm working with swift.
Thank you :D
If you need an in-memory cache try the following library:
http://realm.io
If you need some kind of persistent database here are some options:
YapDatabase (key-value SQLite wrapper)
Realm.io (it fits for such purposes too)
Core Data (seems that it is too complicated solution for your issue)
This might help to you in caching, which code has written in swift. Code is here!
I have been tasked with creating an iPhone application for a client.
I have some coding experience but only in C# so it doesn't really help here but other than that I am a complete novice on iPhone coding.
What I am trying to accomplish is to get some form of store locator on a map.
I have successfully added the map, get the user location with it zooming into the user. I have added 2 annotations (Which I believe the the best way to go about showing locations on the map).
I have 2 queries that I need help with, What is the best way to go about listing the stores in some form of database. XML, PList, .sql etc... (this would also need to be read from the web as it would need to be easily edited as new stores would be added a lot). Is it possible to loop through the database and dynamically add the stores onto the map within a location of the user?
I am not asking anyone to write any code for me, I am just asking for some help as I have googled the hell out of this and cant seem to find anything that helps.
Any help would be much appreciated,
Thanks
In terms of your potential formats for saving these locations, you options include:
XML/JSON are good formats for exchanging data with a remote server, but less ideal for a local database (though they theoretically could be used for that purpose). JSON is marginally easier to deal with (using NSJSONSerialization), but XML can be relatively easily parsed, too (using, for example, NSXMLParser). If you're doing network operations, I also heartily recommend looking at AFNetworking, which offers some nice advantages over the standard NSURLConnection. This, of course, presumes that you have written a web service on your server to deliver the necessary JSON or XML feed.
Plist is a fine, simple format if you want to save a short, local list of locations on iOS devices. Saving data to a plist is as simple as calling writeToFile method for your NSDictionary or NSArray and reading data is done via [NSDictionary dictionaryWithContentsOfFile:filename] or [NSArray arrayWithContentsOfFile:filename].
Core Data is a good, iOS-specific format for larger databases. It's probably the preferred iOS mechanism for dealing with persistent objects, but is an order of magnitude more complicated than plists.
SQLite is also a good database format if you're thinking about a structure that lends itself towards larger database, but also which lends itself towards eventual rollout to multiple platforms (e.g. both Android and iOS). If you decide to go SQLite route, consider an Objective-C wrapper (such as FMDB), which will simplify your life greatly.
Implicit in all of the above discussion is that, yes, you certainly can write code that iterates through your database and/or model data structures, extracting the necessary location information, and dynamically add annotations to your map. The Location Awareness Programming Guide should help introduce you to some of the MapKit related features.
"Is it possible to loop through the database and dynamically add the stores onto the map within a location of the user?"
Yes. Just as you have created those first two annotations, you now need to create more annotations in a loop. The only additional info you might need is that once you have added an annotation to the map it will stay there until you remove it. So you don't need to maintain your own list of annotations unless you want to do something else with it. Just fire and forget. So now your question comes down to how to loop through data from your chosen data source in Objective-C and not MapKit specific.
I know this is old but if anyone else comes across this like I did, you can use tmysqlkit by tanmay bakshi to read and write directly to a mysql database on a server.
Best,
Sam
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.
Alrighty,
I am new to Xcode so I apologise if I am missing any key points here.
But, I want to have a large list in a UITableView type display. The list will be an array of strings with maybe 500 ish entries and a search bar to search for what ever entry you like. Once found you can tap the entry and it will load a detailed view of what ever it is. I would prefer to not have to have all of the data entry in Xcode and am wondering what would be the neatest way to store/read/write this?
I am leaning towards some sort of data file... but couldnt quite work out how to implement this into Xcode. I have searched around a bit but couldnt find anything which made sense (probably because i am quite new to Xcode).
This will be an App for iOS.
Any ideas?
I understand that you want to create a UITableView displaying static data and your problem is that you don't want to store the data in your code. Depending on how complicated the structure of your data is you could save it in a sql database, store it with coredata, keep it in a xml file or keep it in a file in a custom encoding. I don't quite now where your Problem lies. You can just load the file/database, parse it in an object structure and display it in the tableview. There are a couple of advantages of using a database to a file:
You can create connections easily and handle them without a lot of effort
You only need to load in the memory what is really needed at the moment.
Core data will be fine for you. However if you don't need all of its extra functions and the list will be static (eg, non changing and will be read into the code at runtime in its entirerty) then you can probably use a plist. Plist data can be read directly into arrays.