Why and how to use the @xml/file_paths resource in Android Studio?

Question

tl;dr: Why do I need a file_paths resource, when I retrieve a file_path dynamically during runtime?

I am currently learning Android Studio by building my own app. What I want to do right now is to take a picture and then get some Text out of it. To take a picture and use it lateron, I followed the Taking Photos Simply guide of the Android Developers. At this point, it is suggested to use a File Provider.

In the manifest, the File Provider is added like this:

<provider
    android:name="android.support.v4.content.FileProvider"
    android:authorities="com.mydomain.fileprovider"
    android:exported="false"
    android:grantUriPermissions="true">
    <meta-data
        android:name="android.support.FILE_PROVIDER_PATHS"
        android:resource="@xml/file_paths" />
</provider>

I am struggling with the meta-data, especially the android:resource=@xml/file_paths"

In the Taking Photos Simply Tutorial, this is the required addition to the XML to make it work:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="my_images" path="Android/data/com.example.package.name/files/Pictures" />
</paths>

So my question is: What is the good practise intended within the developer guide that I should follow, and how do I do that?

Edit: To make things clearer, I am having trouble understanding how to use a resource here at all. This is the method code straigh out of the guide:

private File createImageFile() throws IOException {
        // Create an image file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
        File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        File image = File.createTempFile(
                imageFileName,  /* prefix */
                ".jpg",         /* suffix */
                storageDir      /* directory */
        );

        // Save a file: path for use with ACTION_VIEW intents
        currentPhotoPath = image.getAbsolutePath();
        return image;
    }

So I am dynamically getting the name of the file (and therefore it's file path) during the Runtime of my application. What is that file/paths for, I do not understand its usage.

Answer 1

Create a folder in the res directory and name it xml, create a file file_paths in it and replace everything with this:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-files-path name="my_images" path="Pictures" />
</paths>

if you want to preview the captured image from that tutorial then decode the file from its path to bitmap and then display it onto a ImageView from the onActivityResult()

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
        val bitmap=BitmapFactory.decodeFile(currentPhotoPath)
        imageView?.setImageBitmap(bitmap)
    }
}