Implementing data synchronization between IndexedDB and local storage

01 Oct 2023

Data synchronization is a critical aspect of modern web applications to ensure seamless use across multiple devices and maintain data consistency. In this blog post, we will explore how to implement data synchronization between IndexedDB and local storage, two popular client-side storage mechanisms.

Understanding IndexedDB and Local Storage

IndexedDB and local storage are both client-side storage options available in modern web browsers. They allow developers to store data persistently on the user’s device. However, there are a few key differences between the two:

IndexedDB: IndexedDB is a more advanced option that provides a powerful database-like interface. It offers features like indexing, querying, and advanced transaction management. IndexedDB is ideal for applications that require complex data operations or deal with large amounts of data.
Local Storage: Local storage is a simpler key-value based storage mechanism. It allows developers to store small amounts of data (typically in string form) on the user’s device. Local storage is suitable for lightweight applications that don’t require complex data operations or large storage capacity.

Implementing Data Synchronization

To implement data synchronization between IndexedDB and local storage, we can follow these steps:

Establish an initial connection to both IndexedDB and local storage.

// Connect to IndexedDB
const indexedDBConnection = indexedDB.open('myDatabase', 1);

// Connect to local storage
const localStorageConnection = window.localStorage;

Retrieve the data from the source storage (IndexedDB in this example).

indexedDBConnection.onsuccess = function(event) {
  const db = event.target.result;
  const transaction = db.transaction('myStore', 'readonly');
  const objectStore = transaction.objectStore('myStore');
  const request = objectStore.getAll();

  request.onsuccess = function(event) {
    const data = event.target.result;
    // Handle retrieved data
  };
};

Write the retrieved data to the target storage (local storage).

indexedDBConnection.onsuccess = function(event) {
  const db = event.target.result;
  const transaction = db.transaction('myStore', 'readonly');
  const objectStore = transaction.objectStore('myStore');
  const request = objectStore.getAll();

  request.onsuccess = function(event) {
    const data = event.target.result;
    localStorageConnection.setItem('myData', JSON.stringify(data));
  };
};

Whenever changes occur in the source storage (e.g., new data is added or existing data is updated), update the target storage accordingly.

indexedDBConnection.onsuccess = function(event) {
  const db = event.target.result;
  const transaction = db.transaction('myStore', 'readwrite');
  const objectStore = transaction.objectStore('myStore');
  const request = objectStore.put({ id: 1, name: 'John Doe', age: 30 });

  request.onsuccess = function(event) {
    const updatedData = event.target.result;
    localStorageConnection.setItem('myData', JSON.stringify(updatedData));
  };
};

Conclusion

Implementing data synchronization between IndexedDB and local storage enables seamless data management in web applications across multiple devices. By following the steps outlined in this blog post, you can ensure data consistency and provide a better user experience. Remember to handle conflicts and implement error handling to account for potential synchronization issues.

#webdevelopment #datastorage