What is @aws-amplify/datastore?
@aws-amplify/datastore is a library that provides a programming model for leveraging shared and distributed data without writing additional code for offline and online scenarios. It is part of the AWS Amplify framework and is designed to work seamlessly with AWS AppSync for real-time and offline-first data access.
What are @aws-amplify/datastore's main functionalities?
Model Definition
Defines the data model schema for the application. This is the first step in setting up DataStore, where you define the structure of your data.
const { initSchema } = require('@aws-amplify/datastore');
const { schema } = require('./schema');
const { Post } = initSchema(schema);
CRUD Operations
Provides basic CRUD (Create, Read, Update, Delete) operations for interacting with the data models. This allows developers to easily manage their data.
const { DataStore } = require('@aws-amplify/datastore');
// Create
await DataStore.save(new Post({ title: 'New Post', content: 'This is a new post' }));
// Read
const posts = await DataStore.query(Post);
// Update
const original = await DataStore.query(Post, '123');
await DataStore.save(Post.copyOf(original, updated => {
updated.title = 'Updated Title';
}));
// Delete
await DataStore.delete(Post, '123');
Real-time and Offline Sync
Enables real-time data synchronization and offline capabilities. DataStore automatically syncs data between the local store and the cloud, ensuring data consistency.
const { DataStore } = require('@aws-amplify/datastore');
DataStore.observe(Post).subscribe(msg => {
console.log(msg.model, msg.opType, msg.element);
});
Conflict Resolution
Handles conflict resolution when data changes occur both locally and in the cloud. Developers can define custom conflict resolution strategies.
const { DataStore, syncExpression } = require('@aws-amplify/datastore');
DataStore.configure({
syncExpressions: [
syncExpression(Post, () => {
return post => post.status('eq', 'published');
})
]
});
Other packages similar to @aws-amplify/datastore
redux-persist
redux-persist is a library that allows you to save the Redux store in persistent storage, such as local storage. It provides offline capabilities but lacks the real-time synchronization and conflict resolution features of @aws-amplify/datastore.
dexie
Dexie is a wrapper for IndexedDB, providing a more straightforward API for managing local databases. While it offers offline storage, it does not provide built-in real-time synchronization or integration with cloud services like @aws-amplify/datastore.
pouchdb
PouchDB is an open-source JavaScript database that syncs with CouchDB. It offers offline-first capabilities and real-time synchronization, similar to @aws-amplify/datastore, but requires a CouchDB server for cloud synchronization.