As you see on app like facebook, twitter, etc you have list of content in home page. if you close the app then open it again, you still have those content without load again from server.
currently i use this code to save all value in my app
SPref.setPref(getActivity(), Config.USER_ID, lb.userId);
SPref.setPref(getActivity(), Config.USER_NAME, lb.name);
SPref.setPref(getActivity(), Config.USER_EMAIL, lb.email);
its just save a string or a an int value not a list. i used saving data at local device with sqlite and a file for my other project. in this case in my new project, i want to make sure which way is better for saving list value.
by the way, i use SharedPreferences because someone told me its faster.
shared preference
is only to store KEY , VALUE pair, So you can store here small amount of data like username , some flags etc.
To store your normal contents like here you want to store list.
Use SQLite for this is the list will not frequently going to changed, or it will going to modify then use Cache.
Please follow this links for better understanding
https://developer.android.com/guide/topics/data/data-storage.html
https://developer.android.com/reference/android/util/LruCache.html
Shared Preferences certainly are very fast, but those aren't meant to be stored with a huge data set, As the name suggest those are meant to store the preference data of the app in a key value pair for example
setting the sound on/off
setting the logged in status
setting the day/night theme for the app.
In the above example whenever user changes a setting you can just store it in SP, and use it next time to make any decisions
For Larger data set, you have to use SQL lite
https://developer.android.com/training/basics/data-storage/databases.html
Or Realm DB(Third party library)
https://realm.io/
Related
I have multiple views that user-entered data can be stored in. I also have views that don't do anything except for decoration, like spaces and dividers.
How can I save everything on screen so that when the app closes and I go back in everything is as I left it?
There are many ways to persist data on Android-
File Storage (Internal / External) : Ideal for storing big files(Photo / video etc)
Shared Preferences : Ideal for storing text values(Configuration values)
Database : Ideal for storing structured data (List of items etc)
For your use case, check out shared preferences.
Learn more about it from the official android guide
If you want users data to be persisted use below:
1. Shared preference if data is less
2. Room database to store large data set
I am new to Android. I am building a test application where I need to store a variable's value say, strength of the user. I want to increase or decrease this strength's value whenever user uses the app. And after user closes the app and reopens it on next day, he should find the same value of strength.
One way I can think of is to store a local db in phone and read/write each time into that, since there are hardly 3 to 4 such variables. So db is not a good option I guess.
Other one I thought was to use android.app.Application class but I am not able to get what I want from that. Can we actually do it using android.app.Application? Or then any other method for 3 to 4 variables.
You can use SharedPreferences to store your variable inside shared preferences. For example, set it like:
SharedPreferences sharedPreferences = context.getSharedPreferences("DATA",Context.MODE_PRIVATE);
sharedPreferences.edit().putString("STRENGTH",yourVar).apply();
Then get it out using:
SharedPreferences sharedPreferences = context.getSharedPreferences("DATA",Context.MODE_PRIVATE);
strength = sharedPreferences.getString("STRENGTH",null);
Use SharedPreferences. SharedPreference provides an easy mechanism to persist a value across the life of an app.
Write an XML file in the application directory that the application can read on startup.
Use application class when our app is open read last state and store your data in shared preference, and you are right db is not good choice.
Like you suggested, you can use an SQLite database to store a table regarding the users. Although, you might only have one variable, strength, associated with each user now but if there's potential for more associated values that you want to store regarding the user, I'll recommend using an SQLite database.
Another option you can use is SharedPreferences, it allows you to store key value pairs. So in your case, each strength value can correspond to a username.
If you haven't learned the different storage options for Android, I'll recommend you taking a look at this.
Hope this helps!
Can I use a column in table to check if user has logged in.
When user logs in I set value to 1. When he logs out I set to 0.I dont want to use SharedPreferences. Is using it like this inefficient.
I used sharedpreferences first. I set username in the sharedpreference along with other preferences and display username in the nav drawer. When I install the app in another device, I think even the sharedpreference file will be installed and I saw that in the new device the username is displayed in the from the sharedpreference file though that user doesn't exist in the table in that device's database
When user logs in I set value to 1. When he logs out I set to 0
Here, what will happen is when you set values to 0 or 1 you have to open and close database everytime and will be a hastle to maintain. you have to check it each time what flag is. while in SharedPreferences it will be globally accesible and easy to set flag.
I would suggest you to use SharedPreferences because
SharedPreferences is a key/value store where you can save a data under certain key. To read the data from the store you have to know the key of the data. This makes reading the data very easy. But as easy as it is to store a small amount of data as difficult it is to store and read large structured data as you need to define key for every single data, furthermore you cannot really search within the data except you have a certain concept for naming the keys.
To give an example, SharedPreferences are useful for storing user preferences, where there are just a handful of variables that need storing. SQLite on the other hand would be better for storing data where there is a large set of items, such as song titles in a music library which need to be searched through
Check SharedPreferences and SQLite.
Better to use Shared Preferences instead of using Database for such a small thing.
Refer this : http://www.androidhive.info/2012/08/android-session-management-using-shared-preferences/
I know this topic has been discussed before on Stack Overflow. But there are still some things that are not clear when I read previous posts about it. So here they are:
I know that we use shared preference for small datasets and sqlite for large data manipulation, so if we just want to save a username and password should we use shared preferences?
Won't shared preferences be lost when user uninstalls the app? For example I download an app called abc and save my username and password. Then I uninstall this app from one phone and try to access it from other phone using the same username and password. Will this be saved using shared preferences or the data be lost?
What are the main reason we use one over the other beside large and small datasets?
You can think of the difference between shared preferences and an SQLite database in terms of data size but that isn't entirely accurate. A better way to think of it is in terms of the structure of the data you want to store.
Shared preferences can only store key-value pairings whilst an SQLite database is much more flexible. So shared preferences are particularly useful for storing user preferences, e.g. should the app display notifications etc. Whilst an SQLite database is useful for just about anything.
Both data sources are local but something you should be aware of is the ability to backup your application data to cloud storage that is linked to the user's Google account. This makes it much easier for your users to change devices and for their applications to easily transfer to the new device. For more info take a look here.
In the situation you described about you will lose the user name and password in both situations. The data is stored on the phone, when you uninstall the application, the data that some with it will also be lost. The user will have to re-enter this information.
You can save the user name and pass in either the shared Preferences or a DB, that is personal preference. Just make sure you lock either down, i.e. don't share the DB or Shared Preferences that you keep this information in.
As for the difference... shared Preferences should hold well... shared Preferences... here is an example:
If I create an option to change the background color, I will store all available options in a DB that can be loaded into a adapter view for the user to choose from. But I will store the color that they have selected in the Shared Preferences. This way when the application load I can get the Shared Preference value of the background color that should be used.
SharedPreferences is used for just that, storing user preferences shared application-wide. You can use it, for example, to store a user's username, or perhaps some options he or she has configured in your app in which you want to remember.
SQLite is a relational database. It's used to store your application's data, not preferences or configuration information.
Both are stored locally on the device.
1.SharedPreferences stores only Boolean, int, float, long, String five kinds of simple data types, such as can not be conditional query. So, whether SharedPreferences data storage operation is how simple it can only be a supplement of storage, but can not completely replace other data such as the SQLite database is stored.
2.SharedPreferences based on the XML file to store key-value key used to store configuration information(mainly user preference for your application).
3.Sharedprefrece just like cookies in web which store some basic information at client side.
both store their data locally, so uninstalling the app will delete both. other than that, SharedPreferences is easier to program, and you're right about the data amounts.
In general, shared preferences should be used if you want to allow your user to directly manipulate certain data fields. Shared preferences are basically user preferences; if you would like the user to reconfigure the app to behave in different ways, you should expose that functionality as a shared preference. On the other hand, the SQLite database should be used if you want to limit the visibility of the data to just the application, if you want a stronger guarantee that the data be persistent, and if you want the application to behave independently of what is stored in the database. Of course, you can use both in one application.
Shared preferences and the database are part of local data that the application stores. If you uninstall the application, both of the data stores will be removed.
For my newest app it it one that will save multiple EditTexts where the user can enter stuff.Like say if it was a note app,how would i get them to save?
There are multiple ways to store data on Android. Read about data storage.
In your case you might have multiple text records with some metadata (time when created, etc..), so I'd recommend the database.
Check out how to store preferences with android's "SharedPreferences":
http://www.javacodegeeks.com/2011/01/android-quick-preferences-tutorial.html
This way you can indefinitely store whatever you're working with as a string, object, etc. Also, you can check out how to work with android's SQLite Database, which might be harder to figure out when you start working with it, but it gets easier over time.