Implementing data backup and restore in IndexedDB

01 Oct 2023

In web applications, it is crucial to have a reliable mechanism for backing up and restoring data. IndexedDB, a powerful browser-based database, provides the ability to store and manipulate large amounts of structured data. In this blog post, we will guide you through the process of implementing data backup and restore functionality in IndexedDB using JavaScript.

Setting up IndexedDB

To get started, we need to set up an IndexedDB instance. Let’s assume that we have already created an object store called “records” to store our data.

// Open or create IndexedDB database
const request = indexedDB.open('myDatabase', 1);

// On database upgrade, create object store
request.onupgradeneeded = function(event) {
  const db = event.target.result;
  const objectStore = db.createObjectStore('records', { keyPath: 'id' });
  // Modify this block to add any other indexes or properties needed for your data
};

// On successful database opening
request.onsuccess = function(event) {
  const db = event.target.result;
  // Use the db variable to interact with the IndexedDB
  // For simplicity, we will be focusing on backup and restore operations in this blog
};

Backing Up Data

To back up the data from our IndexedDB store, we can use the IndexedDB Databases API. This API allows us to export the contents of an IndexedDB database as a backup file.

const request = indexedDB.databases();

request.onsuccess = function(event) {
  const databases = event.target.result;
  
  for (let i = 0; i < databases.length; i++) {
    const db = databases[i];

    // Export the IndexedDB database as backup file
    const backupRequest = indexedDB.backup(db.name);

    backupRequest.onsuccess = function(backupEvent) {
      const backupData = backupEvent.target.result;
      
      // Process the backupData as needed (e.g., store it on a remote server, save to local file)
    };
  }
};

Restoring Data

To restore the data from a backup file, we can use the IndexedDB Databases API and import the backup file into an IndexedDB database.

const fileInput = document.getElementById('backupFile');

fileInput.addEventListener('change', function(event) {
  const file = event.target.files[0];
  
  const reader = new FileReader();

  reader.onload = function(fileEvent) {
    const backupData = fileEvent.target.result;

    // Import the backup data into an IndexedDB database
    const restoreRequest = indexedDB.restore();

    restoreRequest.onsuccess = function(restoreEvent) {
      const db = restoreEvent.target.result;
      
      // Use the db variable to interact with the restored IndexedDB data
    };

    restoreRequest.onerror = function(restoreEvent) {
      console.error('Failed to restore IndexedDB data:', restoreEvent.target.error);
    };

    // Provide the backup data to the restore request
    restoreRequest.result = backupData;
  };

  reader.readAsArrayBuffer(file);
});

Conclusion

By implementing data backup and restore functionality in IndexedDB, you can ensure the reliability and integrity of your web application’s data. Whether it is to back up data periodically or to restore data in case of a failure, IndexedDB provides the necessary tools to handle these scenarios.

Remember to regularly backup your data and test the restore process to ensure the backups are working as expected. With these measures in place, you can have peace of mind knowing that your data is safe and recoverable.

#webdevelopment #indexeddb