DPrefs is an Android library which takes care of all your key value shared preferences needs. This library handles everything for you and also encrypts your saved preferences thereby ensuring that your preferences data are securely saved and prevents information theft.
You can save all kinds of values such as:

• String
• Int
• Float
• Boolean
• Long
• Double and
• Custom object

• Import the Library

Import the library to your project by adding the library into your app level build.gradle file as shown below:

dependencies {
  implementation "com.github.D-Soft-Tech:DPrefs:$version"
}

Because the library is hosted on jitpack, You also need to add jitpack to your project if you haven't added it before:

allprojects {
  repositories {
    maven { url 'https://jitpack.io' }
  }
}

• Initialize the library

Initialize the library in the application class, this will make the library have an application wide scope and make the preferences you saved with it to be available throughout the application. This is the recommended way

- Kotlin:

class MyApplicationClass : Application() {
    override fun onCreate() {
        super.onCreate()
        DPrefs.initializeDPrefs(applicationContext)
    }
}

- Java:

public class MyApplicationClass extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        DPrefs.INSTANCE.initializeDPrefs(getApplicationContext());
    }
}

If for any reason you want the preferences to only have an activity scope, then instead initialize the library in the onCreate() callback function of the activity as shown below:

- Kotlin:

class MyActivity : AppCompatActivity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    DPrefs.initializeDPrefs(this)
  }
}

- Java:

public class MyActivity extends AppCompatActivity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    DPrefs.INSTANCE.initializeDPrefs(this);
  }
}

That is all you need to do in other to set up the library

• To save a value
  To save any value of any type you have to call DPrefs which is the instance of the library exposed to you by the library itself and call the method put\<DataTypeOfValue\>(key, value) where key is a string and value is what you want to save and is of type 'DataTypeOfValue'

** Hence the Nomenclature the library follows is like so: **

DPrefs::put(key, value)
Note: The key must always be a String

For example:

1. to save a string of value 'String value to save' using the key 'STRING_VALUE_KEY'

- Kotlin:

  val key = "STRING_VALUE_KEY"
  val value = "String value to save"
  DPrefs.putString(key, value)

- Java:

  String key = "STRING_VALUE_KEY";
  String value = "String value to save";
  DPrefs.INSTANCE.putString(key, value);

2. to save an int value 12345 using the key 'INT_VALUE_KEY'

- Kotlin:

  val key = "INT_VALUE_KEY"
  val value = 12345
  DPrefs.putInt(key, value)

- Java:

  String key = "INT_VALUE_KEY";
  int value = 12345;
  DPrefs.INSTANCE.putInt(key, value);

The above two examples show the convention that saving a preference using the DPrefs library follows. The only exception to this is putting an object and this is as shown below:

3. to save an object of type UserInfo shown in the json payload below:

{
 "firstName": "Adebayo",
 "lastName": "Oloyede",
 "age": 31,
 "address": "Oyo state, Nigeria",
 "latitude": 3.3456987,
 "longitude": 7.432765,
 "isLoggedIn": true
}

The UserInfo data class can be modelled from the above json payload. like so:

The UserInfo data class can be modelled from the above json payload. like so:

// UserInfo Model
data class UserInfo(
val firstName: String,
val lastName: String,
val age: Int,
val address: String,
val latitude: Double,
val longitude: Double,
val isLoggedIn: Boolean
)

• Sample Usage Kotlin

// Instantiate an object of UserInfo
val userA = UserInfo("Adebayo", "Oloyede", 31, "Oyo state, Nigeria", 3.3456987, 7.432765, true)

// save userA as preference
val objectKey = "OBJECT_VALUE_KEY"

DPrefs.putObject(objectKey, userA)

• Sample Usage Java

 // Instantiate an object of UserInfo
 UserInfo userA = new UserInfo("Adebayo", "Oloyede", 31, "Oyo state, Nigeria", 3.3456987, 7.432765, true);

 // save userA as preference
 String objectKey = "OBJECT_VALUE_KEY";
 DPrefs.INSTANCE.putObject(objectKey, userA);

• Fetching a preference value To get a particular preference value from the library, you only need to supply the key with which you saved the preference value and a default value. This will return the saved value or the default value provided. In the event that the no value exists for the key provided and no default value is supplied, a default value provided by the library is returned.

For example:

1. To get a String

   - Kotlin:

   val key = "STRING_VALUE_KEY"
   val defaultValue = "NO_VALUE"
   val savedString = DPrefs.getString(key, defaultValue)

   - Java:

   String key = "STRING_VALUE_KEY";
   String defaultValue = "NO_VALUE";
   String savedString = DPrefs.INSTANCE.getString(key, defaultValue);

2. To get a Int

   - Kotlin:

   val key = "INT_VALUE_KEY"
   val defaultValue = 10
   val savedInt = DPrefs.getInt(key, defaultValue)

   - Java:

   String key = "INT_VALUE_KEY";
   int defaultValue = 10;
   int savedInt = DPrefs.INSTANCE.getInt(key, defaultValue);

The above two examples show the convention for getting a preference using the DPrefs library. The next item shows how to fetch an object:

3. to get an object of type UserInfo saved above

   - Kotlin:

   val key = "OBJECT_VALUE_KEY"
   val savedObject = DPrefs.getObject(key, UserInfo::class)

   - Java:

   String key = "OBJECT_VALUE_KEY";
   UserInfo savedObject = DPrefs.INSTANCE.getObject(key, UserInfo.class);

Kindly check the DPrefsDefaultValue section for the full list of the default value that can be returned by the library.

• Removing a preference value To remove a saved preference value, you only need to pass the key. The example below how to remove a string value that was saved using the key 'STRING_VALUE_KEY'. The same approach can be followed for int, boolean, object etc.

Sample code:

- Kotlin:

val key = "STRING_VALUE_KEY"
DPrefs.removePref(key)

- Java:

String key = "STRING_VALUE_KEY";
DPrefs.INSTANCE.removePref(key);

• To check whether a key already exist Call doesKeyExists and pass it the key. This will return a Boolean that tells whether the key exist or not. See example below:

- Kotlin:

val key = "STRING_VALUE_KEY"
val keyExist = DPrefs.doesKeyExists(key)

if(keyExist) println("True") else println("False")

- Java:

String key = "STRING_VALUE_KEY";
boolean keyExist = DPrefs.INSTANCE.doesKeyExists(key);

if(keyExist) {
   System.out.println("True");
} else {
   System.out.println("False");
}

• Clearing all the Preferences To remove all the preference that has been saved all at once, call clearAllPrefs on the instance of the library as shown in the sample code below:

Sample code for clearing the preferences:

- Kotlin:

DPrefs.clearAllPrefs()

- Java:

DPrefs.INSTANCE.clearAllPrefs();

There are two exceptions that can be thrown by the library which are:

1. DPrefsNotInitializedException

This is thrown when you try to use the library without first initializing it, to resolve this, go to your application class to initialize the library as shown above.

2. DPrefsKeyAlreadyExistsException

This is thrown when you try save a preference value with a key that already exist. To resolve this, just use another set of character strings.

This is an enum which represent the default value that the library returns in the case that no value is found and no defaultValue is set. There are various instances of it as shown in the list below:

1. • DPrefsDefaultValue.DEFAULT_VALUE_STRING

   This is a default String that can be returned by the library and it's value is an empty string ""

2. • DPrefsDefaultValue.DEFAULT_VALUE_INT

   This is a default Int that can be returned by the library and it's value is -1111111

3. • DPrefsDefaultValue.DEFAULT_VALUE_BOOLEAN

   This is a default Boolean that can be returned by the library and it's value is false

4. • DPrefsDefaultValue.DEFAULT_VALUE_FLOAT

   This is a default float that can be returned by the library and it's value is -0.1000001F

5. • DPrefsDefaultValue.DEFAULT_VALUE_LONG

   This is a default Long that can be returned by the library and it's value is -1111111L

6. • DPrefsDefaultValue.DEFAULT_VALUE_DOUBLE

   This is a default Double that can be returned by the library and it's value is -0.1000001