Caching is an essential technique for improving the performance and user experience of web applications. The JavaScript Cache API provides a straightforward way to store and retrieve resources, such as HTML, CSS, JavaScript files, and images, in the browser’s cache. In some scenarios, you may need to use multiple caches to manage your resources more efficiently.

Table of Contents

• Introduction to the Cache API
• Using multiple caches
• Example: Using multiple caches
• Conclusion

Introduction to the Cache API

The Cache API, introduced in the Service Workers specification, allows you to create, store, and retrieve named caches in the browser’s cache storage. You can add resources to a cache by making a network request and storing the response, or by directly adding resources from your code. The Cache API provides methods like add(), addAll(), match(), and delete() to manipulate the cache.

Using multiple caches

When you want to manage different types of resources separately or have different cache update strategies for different resources, using multiple caches can be beneficial. For example, you might have a cache for static assets like CSS and JavaScript files, another cache for API responses, and a separate cache for images.

Using multiple caches allows you to organize and isolate resources effectively. Each cache can have its own set of resources and expiration policies. It also enables you to control caching behavior more granularly by specifying different rules for each cache.

To use multiple caches, you can create caches with different names using caches.open('cacheName'). Once you have multiple caches, you can use the respective cache name when adding, retrieving, or deleting resources.

Example: Using multiple caches

Here’s an example of using multiple caches with the Cache API in JavaScript:

// Create caches with specific names
caches.open('static-assets')
  .then(cache => {
    // Add CSS and JavaScript files to the static assets cache
    cache.addAll([
      '/css/styles.css',
      '/js/app.js'
    ]);
  });

caches.open('api-responses')
  .then(cache => {
    // Make a network request and store the API response in the api responses cache
    fetch('/api/data')
      .then(response => {
        cache.put('/api/data', response);
      });
  });

// Use the caches

caches.open('static-assets')
  .then(cache => {
    // Retrieve resources from the static assets cache
    cache.match('/css/styles.css')
      .then(response => {
        // Use the response
      });
  });

caches.open('api-responses')
  .then(cache => {
    // Retrieve API response from the api responses cache
    cache.match('/api/data')
      .then(response => {
        // Use the response
      });
  });

In this example, we create two caches, static-assets and api-responses, and add resources to each cache accordingly. We then retrieve resources from the respective caches based on their cache names.

Conclusion

Using multiple caches with the JavaScript Cache API allows you to manage your resources more efficiently and gives you greater control over caching behavior. By organizing resources into separate caches, you can ensure better performance and flexibility when working with cached data. When working with multiple caches, remember to use the appropriate cache name when performing cache operations.