73 lines
2.5 KiB
Dart
73 lines
2.5 KiB
Dart
import 'model.dart';
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import 'objectbox.g.dart'; // created by `flutter pub run build_runner build`
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/// Provides access to the ObjectBox Store throughout the app.
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///
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/// Create this in the apps main function.
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class ObjectBox {
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/// The Store of this app.
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late final Store store;
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/// A Box of notes.
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late final Box<Note> noteBox;
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ObjectBox._create(this.store) {
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noteBox = Box<Note>(store);
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// Add some demo data if the box is empty.
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if (noteBox.isEmpty()) {
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_putDemoData();
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}
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}
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/// Create an instance of ObjectBox to use throughout the app.
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static Future<ObjectBox> create() async {
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// Future<Store> openStore() {...} is defined in the generated objectbox.g.dart
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final store = await openStore();
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return ObjectBox._create(store);
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}
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void _putDemoData() {
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final demoNotes = [
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Note('Quickly add a note by writing text and pressing Enter'),
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Note('Delete notes by tapping on one'),
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Note('Write a demo app for ObjectBox')
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];
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store.runInTransactionAsync(TxMode.write, _putNotesInTx, demoNotes);
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}
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Stream<List<Note>> getNotes() {
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// Query for all notes, sorted by their date.
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// https://docs.objectbox.io/queries
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final builder = noteBox.query().order(Note_.date, flags: Order.descending);
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// Build and watch the query,
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// set triggerImmediately to emit the query immediately on listen.
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return builder
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.watch(triggerImmediately: true)
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// Map it to a list of notes to be used by a StreamBuilder.
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.map((query) => query.find());
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}
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static void _putNotesInTx(Store store, List<Note> notes) =>
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store.box<Note>().putMany(notes);
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/// Add a note within a transaction.
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///
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/// To avoid frame drops, run ObjectBox operations that take longer than a
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/// few milliseconds, e.g. putting many objects, in an isolate with its
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/// own Store instance.
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/// For this example only a single object is put which would also be fine if
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/// done here directly.
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Future<void> addNote(String text) =>
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store.runInTransactionAsync(TxMode.write, _addNoteInTx, text);
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/// Note: due to [dart-lang/sdk#36983](https://github.com/dart-lang/sdk/issues/36983)
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/// not using a closure as it may capture more objects than expected.
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/// These might not be send-able to an isolate. See Store.runAsync for details.
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static void _addNoteInTx(Store store, String text) {
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// Perform ObjectBox operations that take longer than a few milliseconds
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// here. To keep it simple, this example just puts a single object.
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store.box<Note>().put(Note(text));
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}
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}
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