I'm trying to iterate the key in my real-time database, I saw some answers from the past with similar question but it doesn't work on mine. So I need your help once more. I used .push and I tried arraylist but arraylist is a bad idea to be a dynamic output in realtime database.
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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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Closed 6 years ago.
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 creating an iOS trivia game that will have between 1,000 - 10,000 questions in it. Each question will have only two possible answers, so the amount of data per question will be very small.
I'm wondering if I should use Core Data to store the questions or if I can use a large dictionary that I populate when the app loads up?
Would either of those choices work or is there a better solution I haven't considered?
The 'best' way to store these questions depends heavily on your internal data structures, memory usage and source data structures.
How do you receive the questions? If they are an XML then you might like to preserve that structure and implement an XML parser. If Excel format, export to CSV and read from that. JSON: load into an NSDictionary.
If you want to add these into Core Data or sqlite and the source questions are in a different format, you will have to write a parser and importer. Then, if you update questions you will have to create a merge policy etc.
Personally, if you can keep the original format of the data without complicating code/exceeding memory I would keep it simple and go for that - that way, you can replace the source file and it will just work.
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Closed 10 years ago.
Possible Duplicate:
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.
Hello Oracles of StackOverflow,
First time I managed to ask a question on stack overflow, so feel free to throw your cabbages at me. (or correct the way I should be asking my question)
I have this problem. I'm using HDF5 to store massive quantities of cookie information.
My Data is structured in the following way:
CookieID -> Event -> Key_value Pair
There are multiple events for each cookieID. But only one key_value pair per event.
I'd like to know what the best way I should store this in a HDF5.
Currently, I'm storing each cookie as a seperate table within a group in the HDF5, using the cookieID as the name of the table. Unfortunately for me, with 10,000,000 cookies, HDF5 (or specifically PyTables) doesn't approve of this type of storage.
Specifically throwing this error:
/CookieData`` is exceeding the recommended maximum number of children (16384)
I'm wondering if you could recommend the best way of storing this information.
Should I create a flat table? Should I keep this method? Is there something else I can do?
Help is appreciated. Thanks for reading.
Several hours of research later, I've discovered that what I was attempting to do was categorically impossible.
The following link gives details as to the impossibility of using HDF5 with variable-length nested children.
I've decided to go with a flat file for the time being and hope that this is more efficient than a database store. The problem with a flat file in the end is that I have to replicate values in the file, which otherwise should not exist.
If anyone else has any better ideas it would be appreciated.