getString Outside of a Context or Activity

Question

I\'ve found the R.string pretty awesome for keeping hardcoded strings out of my code, and I\'d like to keep using it in a utility class that works with models i

Answer 1

In MyApplication, which extends Application:

public static Resources resources;

In MyApplication's onCreate:

resources = getResources();

Now you can use this field from anywhere in your application.

Answer 2

It's better to use something like this without context and activity:

Resources.getSystem().getString(R.string.my_text)

Answer 3

BTW, one of the reason of symbol not found error may be that your IDE imported android.R; class instead of yours one. Just change import android.R; to import your.namespace.R;

So 2 basic things to get string visible in the different class:

//make sure you are importing the right R class
import your.namespace.R;

//don't forget about the context
public void some_method(Context context) {
   context.getString(R.string.YOUR_STRING);
}

Answer 4

If you have a class that you use in an activity and you want to have access the ressource in that class, I recommend you to define a context as a private variable in class and initial it in constructor:

public class MyClass (){
    private Context context;

    public MyClass(Context context){
       this.context=context;
    }

    public testResource(){
       String s=context.getString(R.string.testString).toString();
    }
}

Making an instant of class in your activity:

MyClass m=new MyClass(this);

Answer 5

Unfortunately, the only way you can access any of the string resources is with a Context (i.e. an Activity or Service). What I've usually done in this case, is to simply require the caller to pass in the context.

Answer 6

Somehow didn't like the hacky solutions of storing static values so came up with a bit longer but a clean version which can be tested as well.

Found 2 possible ways to do it-

1. Pass context.resources as a parameter to your class where you want the string resource. Fairly simple. If passing as param is not possible, use the setter.

e.g.

data class MyModel(val resources: Resources) {
    fun getNameString(): String {
        resources.getString(R.string.someString)
    }
}

2. Use the data-binding (requires fragment/activity though)

Before you read: This version uses Data binding

XML-

<?xml version="1.0" encoding="utf-8"?>

<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">

<data>
    <variable
        name="someStringFetchedFromRes"
        type="String" />
</data>

<TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@{someStringFetchedFromRes}" />
</layout>

Activity/Fragment-

val binding = NameOfYourBinding.inflate(inflater)
binding.someStringFetchedFromRes = resources.getString(R.string.someStringFetchedFromRes)

Sometimes, you need to change the text based on a field in a model. So you would data-bind that model as well and since your activity/fragment knows about the model, you can very well fetch the value and then data-bind the string based on that.