stow_secure #

A storage implementation for Stow using flutter_secure_storage.

A Stow stores one data value, and a SecureStow stores it in secure storage.

Note that the values are stored encrypted and have a small performance penalty compared to stow_plain.

Getting Started #

Run the following in your flutter project:

flutter pub add stow_secure
flutter pub add stow_codecs # (optional)

And define the stows you want somewhere in your code: (Don't worry, this is explained below in the Stow definitions section.)

final stows = Stows();

// Don't worry, this is explained below in the Stow definitions section.
class Stows {
  final username = SecureStow('username', '');
  final secretColor = SecureStow('secret_color', Colors.red,
      codec: ColorCodec());
}

And also make sure to follow flutter_secure_storage's instructions to set up secure storage in your app.

Then you can use the stows like this:

// If needed, wait for it to loaded from disk
await stows.username.waitUntilRead();
// Get the value
print(stows.username.value); // false
// Set the value
stows.username.value = 'johndoe'; // triggers a write to disk
// If needed, wait for it to be written to disk
await stows.username.waitUntilWritten();

And you can listen to changes:

// Manually listen to changes.
stows.username.addListener(_someListenerFunction);
// Always remove the listener in the dispose method or when you're done.
stows.username.removeListener(_someListenerFunction);

// Or use something like Flutter's ValueListenableBuilder
  child: ValueListenableBuilder(
    valueListenable: stows.username,
    builder: (BuildContext context, String username, Widget? child) {
      return Text('Username: $username');
    },
  ),

Stow definitions #

You can define stows in any class/classes you want (they'll be loaded from disk when they're instantiated) but I like to organize them in a single class called Stows.

For each stow, you typically need to provide a key (used by flutter_secure_storage) and a default value to be used when the value is unset.

For the SecureStow to know how to encode your data, you need to use the corresponding constructor or codec:

• For string values, you can just use e.g. SecureStow('key', 'some_default_value').
• For integer values, you can use SecureStow.int('key', 0).
• For other values, find or make a codec that converts your data to a string/integer and use the relevant constructor e.g.:
  • SecureStow('key', 'default', ValueToStringCodec())
  • SecureStow.int('key', 0, ColorCodec())

More information #

Codecs and stow definitions are explained in more detail in the stow_plain package documentation.