Get text from ".txt" file and save it in String variable dart

Question

I have a ".txt" file called "bio.txt" inside the Document folder of my application. I want to read its content and store it inside a String variable. My problem is that the "reading action" is a "Future" function and I have some troubles to save its value in a "String".

I read the file with :

Future<String> get _localPath async {
  final directory = await getApplicationDocumentsDirectory();
  return directory.path;
}

Future<File> _localFile(String name) async {
  final path = await _localPath;
  return File('$path/$name');
}

Future<String> _read(String filename) async {
  try {
    final file = await _localFile(filename);

    // Read the file.
    return await file.readAsString();
  } catch (e) {
    // If encountering an error, return 0.
    return "Can't read";
  }
}

And I would like to save it with :

String _bio = _read("bio.txt").then((value) => String);

Do you know why this solution isn't working? Any suggestion?

Answer 1

Because the then of Futures won't return a value, it should be like this,

var _bio;

_read("bio.txt").then((value) {
  _bio = value;
});

or by making the context _bio is in to an asynchronous one,

var _bio = await _read("bio.txt");

Answer 2

You can either use a then block or use the async/await

_read ('file.txt').then((value){
bio = value;
 });

Or:

bio = await _read ('file.txt');

Answer 3

This is my solution :

String _myRead( String filename){
 var _bio;

 _read("bio.txt").then((String) {
   _bio = String;
 });
 return _bio;
}
String _bio=_myRead("bio.txt");