I am making meeting app and I need to store users data. I am not need to use sql for now because it hard to setting it, so I need place to store data, I not want store users in RAM, so where can I do it? It not necessary to cache images for now, by if I can add it in this place in future it will be great.
Here is what I believe you are asking:
I am developing a meeting app and I need to store some user data.
I dont want to use sql for because its complex to do, so I need
a place to store my data. I not want use up unnecessary RAM,
so where can I store the data? I currently dont have any need
for cacheing images but perhaps in the future.
Not using CoreData/SQL because its hard to understand is not really a good reason. It was the native built in way of data access within iOS and it is the recommended way.
This is a very broad question since we dont know what your data looks like and if there are relationships between them, how large your dataset is, etc.
If its a small enough data list maybe you can look into using a PLIST. It will be a list of values with a key to each one. If its really small you can use NSUserDefaults If its static data, perhaps storing them in a NSArray or NSDictionary
Related
In my iOS app, I need to keep track of which sequence numbers have already been received from the server and which sequence numbers need to be retrieved. I want to be able to store this in case the app terminates or crashes.
I am trying to decide which storage method I should use: core data, plist etc.
The list of sequence numbers is dynamic and can change a lot. Any pointers on how to decide on storage will be greatly appreciated.
Without more exact details in your question it is hard to give you an accurate answer. However, what can be provided is some insights on the benefits / downfalls of using the storage systems listed above.
I would stay away from using a plist since your data is dynamic and can change a lot. Every time you save to a plist you will need to overwrite the entire file. This means to change a single value you must retrieve all values, make a single change, and save all values back to the plist. This isn't a modular way of doing such saves and can become problematic if you have a lot of information that is changing and needs to be saved all the time. On the up side - setting up a plist save / read write structure is very easy and fast.
NSUserDefaults should be used for just that. Saving user settings and preferences. It is really easy to use NSUserDefaults, but may become very problematic in the long run if you data is very large. Values returned from NSUserDefaults are immutable too. This may or may not be a problem for your needs.
CoreData may be overkill for what you're doing, unless your sequence numbers are very large. Personally, I would go with CoreData knowing how it can handle dynamic values and how fast it is to save objects compared to the plist and NSUserDefaults. The down side is CoreData is a bit of a learning curve. Unless you have used it before, it is easy to go down the wrong path using it.
As far as pointers on which storage option to use, do some research. Make a list of pros and cons of each storage option. Ask yourself how big your data may get, and what is the best solution. You already know the data is dynamic and may change a lot. Look at the performance of each storage solution.
Here are some helpful reading material links straight from Apple:
Plist
NSUserDefaults
CoreData
Background:
I have an app that retrieves a list of restaurants from a database, each have an individual array of basic information about them (hours, name, address, etc). I would like to retrieve that information from the server on the apps first load, but then have it stored within the app itself, with either NSUserDefaults or Core Data, since the information is unlikely to change. The max number of restaurants I would be storing is about 25, is that a small enough data collection to use NSUserDefaults?
I have looked at similar questions with storing data with over 1,000 records, but I am only storing a small array.
Question:
NSUserDefaults is much easier to use than Core Data, so if possible I would like to avoid using Core Data. In my case, will there be a performance problem if I am storing my list of restaurants in NSUserDefaults instead of Core Data?
Depends on the
size
structure of data
requirements re integrity of the data
Just an Array of 10 or 20 "restaruants" I would certainly store in NSUserDefaults. But only when I am sure that this will never become more complex. Because when you later extend your model but started off with NSUserData then you may remain with NSUserDefaults just because you avoid migrating it to Core Data during the upgrade of an installed app.
So for more complex structures including references and when you have further plans with your app towards more functionality that may require more entities, then you should go for Core Data from start.
BTW, it is not that complicated as you may think.
However, instead of abusing NSUserDefaults, you could simply write an NSArray to file using -writeToFile:atomically: and -initWithContentsOfFile: to read them in.
NSUserDefaults is not intended for data, it's for storing simple key-value pairs like user settings and flags. Core Data is a bit hard to learn at first, but definitely worth it, even for simple applications.
If it really is a small, simple data set that won't change very often, you can also store some data in a local plist (i.e. save NSArray or NSDictionary to plist using writeToFile method). This isn't very different from using NSUserDefaults in terms of performance, although I think it's cleaner and easier to manage. If it never changes you can also include the plist with your app resources in XCode by creating a plist file and filling it in with your data.
Considering the amount of the data, user default or a specific plist/json file are all good. CoreData is definitely overkilling.
I need to store data that the user can add, they can add an unlimited amount. They can either be NSStrings or UIImages. I have looked into NSUserDefaults but it seems that it is used for small amounts of data such as settings or preferences.
What would be the best/most secure way to store the users information so that when they close the app it is still in the app. The data populates a UITableView and is a NSMutableArray.
Whats the best way to do this?
There must be a dozen ways to store user data in iOS. Here are several:
Property lists: An easy way to store a graph of common data storage objects and containers. This is a good place to start if you're just learning the iOS ropes.
NSKeyedArchiver and NSKeyedUnarchiver: Provides an easy way to serialize and deserialize your objects to/from a chunk of data, which you can then write/read using NSData's methods.
NSFileHandle: Read and write data in whatever format you like using a nice Objective-C API. More generally, you should read up on the iOS file system.
UIDocument: A full-featured starting point for managing user data, including syncing with iCloud.
Keychain: Not a general purpose data storage mechanism, but if you're storing sensitive items like passwords, credit card numbers, etc., you should use the keychain API.
POSIX file API: Good old C file handles with the read and write functions you learned in college, if you went to college before Java was a thing.
SQLite: According to the web site: "SQLite is the most widely deployed SQL database engine in the world."
Core Data: A powerful (but also somewhat complex object graph manager. This is a good choice if you have many different pieces of related data to store.
What would be the best/most secure way to store the users information
so that when they close the app it is still in the app. The data
populates a UITableView and is a NSMutableArray.
Best is subjective -- you'll need to consider your needs and look at the various options. For many people, though, best means least painful or easiest to learn. As mentioned above, property lists may be the way to go in that case. If your array contains simple data (strings, data, dates, numbers) in standard containers (arrays or dictionaries), your file I/O can be as simple as something like this:
// writing
[myArray writeToFile:somePath atomically:YES];
// reading
myArray = [[NSArray arrayWithContentsOfFile:somePath] mutableCopy];
You should use Core Data. There is a very good, free beginners course online avaibable called cs193p, see here http://www.stanford.edu/class/cs193p/cgi-bin/drupal/node/287, it is also available through iTunes U. It's really worth the time to watch and easy understandable.
If you have only some array you can check plist. is verry simple and powerful.
https://developer.apple.com/library/iOs/documentation/General/Reference/InfoPlistKeyReference/Articles/AboutInformationPropertyListFiles.html
This is a great resources: Should I use NSUserDefaults or a plist to store data?
The app that I am working on allows users to favorite podcast channels. I have been told that the best way to keep track of this is through core data. My initial thought was that it was the best way, but after giving it more thought, it seems overkill for this one feature. The way I understand Core Data is that it is Apple's recommended way of implementing the app's model layer, but we are not using it. What would you recommend to accomplish this feature? Also, we are not storing all of our data locally. The only data we are storing is the mp3 files that the user downloads, which are saved into the documents directory.
If you are persisting data (such as podcast urls, episode information, etc.) then you should store all of it in one place. Core Data can do that easily.
How much data are you storing? I would guess from your app description that you have more data than just what is a favorite.
Update
If you are storing a favorite flag you need something to associate it with. A URL perhaps.
If you are storing the URL, you might as well cache the podcast name with it.
If you are storing the name, might as well cache the episodes.
See where I am going? :)
Keep a local cache of what you are getting from the web and the user gets a better experience because they see data on launch, they don't need to wait for the internet which is random.
If you are caching data, then yes! use Core Data. Otherwise, NSUserDefaults is probably sufficient.
I want to store earned xp and gold, so that my game loads the data whenever the game starts. I am using cocos2d on the iPhone, what would be a safe (doesn't need to be toooo safe) to store such data?
I don't want the user to be able to modify the xp-points too easily. Is that possible with .plists? Or do I have to use a Database like SQL lite? It would be very nice if the user couldn't just change the values of the .plist that easily.
It may be easiest to use NSUserPreferences.
How about storing the information in a dictionary, archiving it, then encrypting the data with one of the many available encryption categories like the one shared by Aquatic?
Nothing you can do would stop a determined and experienced hacker but this would make it difficult / effectively impossible for the average user.