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I am newish to Swift/SwiftUI and have been reading a ton of resources. Using what I am learning along with another example app similar to what I am trying to create, I am making an app that downloads a JSON file from an external API service. That JSON data contains the main part of my code (items from a video game), and my app displays that data in various views. My question though is this: I want a user to be able to track a few things about each object, such as whether they have collected it. I have spent 2-3 weeks researching and trying various options of how to do this, but I am wondering what the most efficient/most popular way of doing something like this is in real-world apps?
Here are some things I have been considering:
Download the API JSON initially and then create both it and my collection data as one object. From there, I would persist that data either be encoding back to a JSON file to be stored in the app's documents directory or in Core Data (or even Realm). The views would actually pull from my own personal data. My first concern with this method is that the API JSON may have changes at some point and I would like the app to always have the most up-to-date version of that info (and I don't know how to compare for updated info yet). My second concern is why keep all of that extra info locally in my app when someone else is already hosting it (or should I do that anyway so the app can be used offline)? If that is the case, is there a tutorial or something around that shows how to manage downloaded JSON data without completely overwriting current data?
Download the API JSON as I currently am (every time a view needs it), and store the collection info as its own data. This is the method I think makes more sense, but my question is how do I combine it with the API JSON? Is it easiest to use JSON or Core Data to combine these files? Do I use the Combine framework? Are there other frameworks/methods that would be better suited for that?
To sum up:
My app downloads JSON files from an API containing items from a game that can be collected. I want the user to be able to track whether they have collected said items from that game. I don't know the best way to do this or what framework/classes I should be researching to do this. Any help would be greatly appreciated.
Warning: Most tutorials for CoreData and SwiftUI, FYI, both ignore MVVM (e.g., using #FetchRequest so your view directly reads your model) and the benefits of abstracting your persistence choice with a DataManager object and protocol. Doing the latter lets you choose CoreData now and switch to Google Firebase later (i.e., launching a collaborative Android version), without changing any View code or really any ViewModel code. You can follow the same principles with JSON decoding as just a different DataManger for initializing data for your ViewModel to apportion to views. Ok, done with soap box.
If your dataset is really big and you plan to query it sideways, CoreData may be nice. Or just a skill to learn. It's not that bad.
But if the use case is something simple like
Character 1
-- isStarredAsAwesome
-- copiesCollected
-- maxLevelofCopyCollected
-- dateCollected
Then just save JSON to the Bundle.
The benefit of CoreData is you could query relationships, such as get a brag sheet of which of my video game characters are in my friends library, but at a higher level and played for fewer hours but collected far in the past. In a large dataset, CoreData will be faster than looping over arrays yourself. But for a smaller dataset like yours may be, again, it may not matter really at all.
I'm building a note-taking app with lots of cross-ways uses of entered text. In this case, CoreData was easier than managing all those relationships in JSON, which makes the extra function calls to manage CoreData CRUD calls worth it.
Also, you may want to ship the JSON with your app and then call an updater on launch. This way, in case the API changes, your app isn't immediately broken until you get around to updating it.
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How to make offline database for my app?
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I'm currently working on an application in Xcode 8/Swift 3 which runs through APIs. Essentially, I'm parsing information using SwiftyJSON from my MySQL database which keeps the content current and easily updated.
To keep it so the content is also available offline, I'd like to introduce a facility where the data is downloaded and stored on the phone so it is available in "offline mode".
I know it's a completely open question but can anyone point me in the correct direction of how I could make this JSON information available offline? I've tried searching the net with no success.
I know it's not Swift, but the absolute master of this has recently open sauced his master piece: Dash for iOS.
Reviewing what he's done to get rapid scrolling and searches might give some deep insight into how to best do this as done by someone with (arguably) more experience in this area than anyone other than Apple:
https://github.com/Kapeli/Dash-iOS
I will prefer here 2 option either I will go with 1.SQLite DB or 2. NSURLCache
For SQLite DB you can use FMDB wrapper-https://github.com/ccgus/fmdb
For NSURLCache check this link Best way to Cache JSON from API in SWIFT?
If you just want to save json then go with NSURLCache for offline mode.
Achieving offline for iOS is having two best paths they are CoreData and SQLITE. As per the definition of CoreData suggests it is a Model layer of the project. It comes with less efforts on developer side. Bit contrast SQLITE having the same way but little efforts on it.
In my project we are using the CoreData for offline maintenance. Really we have few concerns on the Relational data fetching, Although there is a Predicates representing CoreData for the same still it is limited to some part. These type of situations SQLITE is really a life saver. We can easily fetch the records with simple JOIN commands.
Conclusion:
If you have more complex data relations it's really better to go with the SQLITE, Apart from CoreData is best choice.
I'm working on a simple ResearchKit app that has 20 survey questions, or ORKSteps. How do I get the answers from a participant who submits the survey into a database?
My research has found ORKESerializer and SQLite as potential parts of the solution. I'm missing a big picture view of how these things can be integrated into a working solution.
Starting without knowledge of databases or data transfer from Swift, so any basic information would be very helpful.
How do I extract data from ORKResult using Swift?
Where do I extract the data to? Or, what's the standard type of database for a small survey?
ResearchKit doesn't have any out-of-the-box solution for storing your results. Generally, it's the task of the developer to go through the ORKResult hierarchy and either persist the processed results for later access or send them to a remote server.
You have several options here:
Use NSCoding to store the vanilla ORKTaskResult (with their ORKResult children). This way you can recreate the whole ORKTaskResult hierarchy at later time to inspect or process it.
Use ORKESerializer (as you guessed) to serialize ORKResults into the JSON format. ORKESerializer is currently included as part of ORKTest's unit tests, and it's not documented very well. It's possible that it will be moved to ResearchKit proper in the future, but it's completely usable right now. The JSON format is particularly useful if you want to send your results to any remote server of your own.
You can manually iterate through ORKResults and convert them into objects that are suitable for storing, or into database records. As you said, you could persist them using SQLite; or other database of your choice; or Core Data.
To sum up, there's no recommended or standard method for persisting results, it depends on your needs.
You can also have a look at the official open sourced RK apps. I think they make use of the AppCore library (which sits on top of the ResearchKit) to store the task results (and also use the Sage Bridge to send the results to Sage's servers). But that may be overboard if your needs are simpler.
I suggest that you run the sample ORKCatalog app and then inspect the ORKTaskResult hierarchy (you can do that within the app itself). You'll get an idea of how the result hierarchy looks.
I do not have experience with the Research Kit but as a database you could use sqlite. stephencelis has made a great wrapper for swift which you can use.
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i would like to know or maybe if someone can guide me what to do. for now im putting my mind on creating an app that gets the featured products on my website, using storyboard. where i click on products on my list in the tables view the it'll send me to next view to choose the product and when i click on the product and it'll go to another view where its details are written. i would know that it'll be done with parsing, or am i wrong.
its like, products --> products name list from web --> details
the interface and the tableview are already set, coding is just missing i just need to know where to begin.
Just a heads up, this question is far too broad for StackOverflow. You need to break this up and ask several smaller questions.
User Loads app, and it makes a request to your webserver asking for product list
(NSURLConnection)
Webserver receives request and sends encoded data back down. XML? JSON? Up to you.
(What software is running on your webserver? PHP? MySQL? Gather data and encode)
App Receives product data. Parse the encoding wrapper to get your object data.
(JSON or XML to NSDictionary, some good libraries available)
Populate data source with this data
Display data
If you have hundreds of products you'll probably need to reproduce this over and over, but that's up to you. If you only have a dozen or so it's probably easier to just send the whole chunk over on app startup.
Ace, if understand you correctly, the products itself should be fetched from the server. Then you can pick one or display the details. So, I would use a framework to connect and get the results from the server. There are things to consider: XML/JSON data parsing and mapping, Storing and caching the products, so you would be able to display them when there is no connections and updating with the latest changes. I am currently using RestKit which handles pretty much all of these things but for JSON. If you consider CoreData (database storage in iOS) you may need some additional help with retrieving the objects - MagicalRecord framework (on top of RestKit). It will handle things like findAll, findByAttribute:name: so you can get the objects you need. These frameworks are somewhat advanced, but on the other hand, they provide a sound ground for the UI stuff.
When you set up the backend integration and get your objects/collection of objects into the client, you can start populating the TableViews and displaying details.
One more thing to consider for a new project - CocoaPods. It is a very nice way to manage third-party libraries and frameworks. You just specify the libs you need and their versions (the good practice is to always specify the version, so the libs stay in sync) and it will fetch them and create a XCode workspace with them, so you don't have to worry about integrating them into the project. Both of the frameworks are there, just use
pods search <your_framework>
Good luck
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I have an app that showcases paintings, the number of paintings is about 600 ( so thats 600 png's ). The client wants me to include those images in the app build, so that they are always available to view even if the user if not online. Of course with every image comes some fields like description, painter, and price estimate, so this app will not stream anything and will have all of its data locally.
Anyway I am thinking of the best way to build this app, I thought of core data, and even encoding decoding, but since These images wil never change, I can put them in an images folder and on viewdidload just loop over contents of the folder and build my tableviewcells.
my question is :
1 : Is this a good architecture?
2 : I need to associate those images with the relevant description of them? whats the best way of doing this? If I jump into core data and create models I feel this would be an overkill.
Keep in mind that these images will never change, nor will the data be updated.
Thanks.
A couple of thoughts:
As discussed in your other question, I think that loading all of these images in the app has its disadvantages, given that you say that the app ends up being 300mb. If it is, indeed, going to be larger than 50mb, then I think you might want try to dissuade your customer from insisting that all of the images be included in the app, itself. I understand that you might not be able to convince them, but at least make sure they understand the implication of including all of these images (that it makes it harder to install the app and therefore, they may experience a lower adoption rate of their new app).
Storing the relevant description of the images in Core Data is a good approach. You could also use SQLite (e.g., via the FMDB wrapper), but I'd really encourage you to just use Core Data unless you have some other considerations you haven't shared with us. But a lot of other traditional solutions for simplified persistent data (plists, NSUserDefaults, etc.) might not be appropriate for this many records. Core Data is great and really isn't that complicated. Sure, the first time you use Core Data, it takes a little getting used to, but it seems well suited for this amount of data.
You talk about "encoding and decoding" of the images, and you haven't described anything that would lead us to suggest that sort of process. What encoding/decoding are you contemplating? It's probably easier to just store the images in the local file system (in the bundle if included in the app, elsewhere in the file system if you're downloading the images on the fly).
You mention that you might have "viewDidLoad just loop over contents of the folder and build my tableviewcells". Perhaps I'm reading too much into this (in conjunction with your other question's comments about receiving memory warnings), but given that you are talking about keeping the images descriptions in Core Data, you don't need to be iterating through anything in viewDidLoad. Your UITableViewDataSource methods will simply query the Core Data database and present the appropriate information. I don't see any need to be iterating through anything in viewDidLoad.
I did a similar kind of application some time ago. I used unique code names for the images and created a Core Data DB that would have one column associating the according line of data (description, author, ...) with the "code" name of the image (i.e., 2347.png).
My model was something simple like this:
NSNumber *imageCode // the number that you would use to associate to your images
NSString *name
NSString *author
NSString *description
I'm assuming that you know how to use Core Data.. if you don't, you can refer to this website: Core Data on iOS 5 Tutorial: Getting Started .. it is really helpful!
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Closed 10 years ago.
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Use CoreData or SQLite on iPhone?
I would like to build an App which enables you too find stores (for example stores with your favourite shoe brand) even when you're not connected with WiFi or 3G.
For now the App should have a couple of possibilities:
User selects his favourite brand and gets a list of nearby stores. After that the user must be able to select a store to get the address, contact information and maybe a map;
User selects a certain city, gets a list of the available brands, selects one and gets a list of stores in that city selling the selected brand.
Since I'm new to making this kind of Apps, I have started doing my homework. I know I have to use a database to store all the data and found out there are a lot of ways to do so. One of them, creating a MySQL Database, wouldn't be an option since it can't be used offline. If I'm right two other methods are SQLite or CoreData.
Problem is, I'm getting kinda lost in all the available information which makes it hard for me to start. Are both methods possible for this App and which one is the easiest for this job?
I was hoping someone could point me in the right direction and maybe give me an usefull link or tutorial to continue with my App.
Thanks in advance! :)
Only use SQLite if you already know it, or you know that your use case is one of the rare few that has proven difficult for Core Data.
Thus, I would think your decision is simple. Use Core Data. It's extremely simple, unless you start updating data from multiple threads/contexts at the same time, then it gets pretty hairy relatively quickly.
There are tons of tutorials available online for Core Data, and ou always have Apple's documentation and sample code on their developer web site.
If you've never used MySQL or SQLite, just use CoreData. But if you have used MySQL or SQLite, i would recommend using SQLite as it will be easy for you to understand and thus you will be able to develop your app faster.