SharedPreferencesHelpers

Since AndroidAnnotations 2.1

SharedPreferences helpers allow you to use Android SharedPreferences, but in a typesafe manner, instead of using strings.

Defining the preferences

First, you should create an interface annotated with @SharedPref to define the SharedPreferences :

@SharedPref
public interface MyPrefs {

        // The field name will have default value "John"
	@DefaultString("John")
	String name();

        // The field age will have default value 42
	@DefaultInt(42)
	int age();

        // The field lastUpdated will have default value 0
	long lastUpdated();

}

Based on that specification, AndroidAnnotations builds a SharedPreferences Helper that has the same name plus an underscore. You can get an instance of the generated helper in an activity with the @Pref annotation.

@EActivity
public class MyActivity extends Activity {

	@Pref
	MyPrefs_ myPrefs;
	
	// ...

}

You can then start using it:

// Simple edit
myPrefs.name().put("John");

// Batch edit
myPrefs.edit()
  .name()
  .put("John")
  .age()
  .put(42)
  .apply();

// Preference clearing:
myPrefs.clear();

// Check if a value exists:
boolean nameExists = myPrefs.name().exists();

// Reading a value
long lastUpdated = myPrefs.lastUpdated().get();

// Reading a value and providing a fallback default value
long now = System.currentTimeMillis();
long lastUpdated = myPrefs.lastUpdated().getOr(now);

Observe that you can name the shared preference by setting value to one of the following:

• ACTIVITY, for a shared preference named MyActivity_MyPrefs;
• ACTIVITY_DEFAULT, for a shared preference named MyActivity (also available through activity.getPreferences());
• APPLICATION_DEFAULT, for the default SharedPreference or UNIQUE, for a shared preference named MyPrefs.

Therefore, if a single shared preference is needed for the interface defined, in order to all activities of a given application to share the same preferences, the following should be used:

@SharedPref(value=Scope.UNIQUE)
public interface MyPrefs {
...

Please note that shared prefs can only be used in activities, due to some compiler specific hairy bugs. If you really think you'd need to use them in another kind of component, please let us know by raising an issue.

If you need more details, Old Issue 47 should give you enough information to get started.

You could also have a look at the functional tests.