dropdownbottomsheet

Description:

dropdownbottomsheet

Drop down sheet plugin viewy #


Wraps platform-specific persistent storage for simple data
(NSUserDefaults on iOS and macOS, SharedPreferences on Android, etc.).
Data may be persisted to disk asynchronously,
and there is no guarantee that writes will be persisted to disk after
returning, so this plugin must not be used for storing critical data.
Supported data types are int, double, bool, String and List<String>.




Android
iOS
Linux
macOS
Web
Windows




Support
SDK 16+
12.0+
Any
10.14+
Any
Any



Usage #
To use this plugin, add DropDownSheet as a dependency in your pubspec.yaml file.
Examples #
Here are small examples that show you how to use the API.
Write data

// Obtain shared preferences.
final SharedPreferences prefs = await SharedPreferences.getInstance();

// Save an integer value to 'counter' key.
await prefs.setInt('counter', 10);
// Save an boolean value to 'repeat' key.
await prefs.setBool('repeat', true);
// Save an double value to 'decimal' key.
await prefs.setDouble('decimal', 1.5);
// Save an String value to 'action' key.
await prefs.setString('action', 'Start');
// Save an list of strings to 'items' key.
await prefs.setStringList('items', <String>['Earth', 'Moon', 'Sun']);
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Read data

// Try reading data from the 'counter' key. If it doesn't exist, returns null.
final int? counter = prefs.getInt('counter');
// Try reading data from the 'repeat' key. If it doesn't exist, returns null.
final bool? repeat = prefs.getBool('repeat');
// Try reading data from the 'decimal' key. If it doesn't exist, returns null.
final double? decimal = prefs.getDouble('decimal');
// Try reading data from the 'action' key. If it doesn't exist, returns null.
final String? action = prefs.getString('action');
// Try reading data from the 'items' key. If it doesn't exist, returns null.
final List<String>? items = prefs.getStringList('items');
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Remove an entry

// Remove data for the 'counter' key.
await prefs.remove('counter');
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Multiple instances #
In order to make preference lookup via the get* methods synchronous,
shared_preferences uses a cache on the Dart side, which is normally only
updated by the set* methods. Usually this is an implementation detail that
does not affect callers, but it can cause issues in a few cases:

If you are using shared_preferences from multiple isolates, since each
isolate has its own SharedPreferences singleton and cache.
If you are using shared_preferences in multiple engine instances (including
those created by plugins that create background contexts on mobile devices,
such as firebase_messaging).
If you are modifying the underlying system preference store through something
other than the shared_preferences plugin, such as native code.

If you need to read a preference value that may have been changed by anything
other than the SharedPreferences instance you are reading it from, you should
call reload() on the instance before reading from it to update its cache with
any external changes.
If this is problematic for your use case, you can thumbs up
this issue to express
interest in APIs that provide direct (asynchronous) access to the underlying
preference store, and/or subscribe to it for updates.
Migration and Prefixes #
By default, the SharedPreferences plugin will only read (and write) preferences
that begin with the prefix flutter.. This is all handled internally by the plugin
and does not require manually adding this prefix.
Alternatively, SharedPreferences can be configured to use any prefix by adding
a call to setPrefix before any instances of SharedPreferences are instantiated.
Calling setPrefix after an instance of SharedPreferences is created will fail.
Setting the prefix to an empty string '' will allow access to all preferences created
by any non-flutter versions of the app (for migrating from a native app to flutter).
If the prefix is set to a value such as '' that causes it to read values that were
not originally stored by the SharedPreferences, initializing SharedPreferences
may fail if any of the values are of types that are not supported by SharedPreferences.
In this case, you can set an allowList that contains only preferences of supported types.
If you decide to remove the prefix entirely, you can still access previously created
preferences by manually adding the previous prefix flutter. to the beginning of
the preference key.
If you have been using SharedPreferences with the default prefix but wish to change
to a new prefix, you will need to transform your current preferences manually to add
the new prefix otherwise the old preferences will be inaccessible.
Testing #
In tests, you can replace the standard SharedPreferences implementation with
a mock implementation with initial values. This implementation is in-memory
only, and will not persist values to the usual preference store.

final Map<String, Object> values = <String, Object>{'counter': 1};
SharedPreferences.setMockInitialValues(values);
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Storage location by platform #



Platform
Location




Android
SharedPreferences


iOS
NSUserDefaults


Linux
In the XDG_DATA_HOME directory


macOS
NSUserDefaults


Web
LocalStorage


Windows
In the roaming AppData directory