77.6 Saving to a Storage File

Now that the application is able to create new storage based files, the next step is to add the ability to save any text entered by the user to a file. The user interface is configured to call the saveFile() method when the Save button is selected by the user. This method will be responsible for starting a new intent of type ACTION_OPEN_DOCUMENT which will result in the picker user interface appearing so that the user can choose the file to which the text is to be stored. Since we are only working with plain text files, the intent needs to be configured to restrict the user’s selection options to existing files that match the text/plain MIME type. Having identified the actions to be performed by the saveFile() method, this can now be added to the MainActivity.kt class file as follows:

fun saveFile(view: View) {

    val intent = Intent(Intent.ACTION_OPEN_DOCUMENT)

    intent.addCategory(Intent.CATEGORY_OPENABLE...