How to load text file into a String variable in Flutter

Question

I've been trying to load a text file into a variable, so that I can check if the user's input is valid. However, I've been having difficulty trying to store the output of the rootBundle.loadString function into a useable String variable, and I'm not sure how to do it.

My code:

Future<String> getFileData(String path) async {
  return rootBundle.loadString(path);
}

String text = getFileData("assets/textfile.txt");

How would I store the contents of a text file in a variable as a string type?

Does this answer your question? [What is a Future and how do I use it?](https://stackoverflow.com/questions/63017280/what-is-a-future-and-how-do-i-use-it) — jamesdlin, Jan 22 '21 at 08:42

Vinoth Vino · Answer 1 · 2021-01-22T03:18:06.817

2

You need to await the loadString method, it's return type is Future<String>.

Future<String> getFileData(String path) async {
  return await rootBundle.loadString(path);
}

String text = await getFileData("assets/textfile.txt");

edited Jan 22 '21 at 03:18

answered Jan 22 '21 at 02:15

Vinoth Vino

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When assigning to a String, it says: `A value of type 'Future' can't be assigned to a variable of type 'String'.`. How would I use the output of this function? – 12 rhombi in grid w no corners Jan 22 '21 at 12:11
Please check this official dart documentation for async programming. @12rhombiingridwnocorners https://dart.dev/codelabs/async-await#working-with-futures-async-and-await – Vinoth Vino Jan 22 '21 at 12:49
sorry if my questions are stupid, but how would you store the Future value as a string instead of printing it? – 12 rhombi in grid w no corners Jan 22 '21 at 13:20
See that link and check ```Example: asynchronous functions```, there ```var order = await fetchUserOrder();```. Here fetchUserOrder() is Future method. Just read that whole article, surely you'll get to know about it. – Vinoth Vino Jan 22 '21 at 13:31
Ohh, I think I see what my problem was. I need to parse through the contents of the file in an async function, right? – 12 rhombi in grid w no corners Jan 22 '21 at 14:10

How to load text file into a String variable in Flutter

1 Answers1