Site Manifest Cache

Deprecated Feature: As of version 1.4, the cache_manifest configuration option is deprecated and no longer has any effect. The manifest caching strategy was removed to simplify the Workbox configuration. This page is maintained for reference purposes only.

Background

The Site Manifest file (manifest.json) is automatically served by your application and is typically very small (a few kilobytes). Previously, the bundle provided an option to cache the manifest file using Workbox.

/config/packages/pwa.yaml

pwa:
    serviceworker:
        workbox:
            cache_manifest: true  # DEPRECATED - No longer functional

Why Was It Removed?

The manifest caching feature was removed in version 1.4 for several reasons:

1. Minimal benefit: The manifest file is small and loads quickly even without caching

2. Browser caching: Browsers already cache the manifest file using standard HTTP caching

3. Rare access: The manifest is only accessed during PWA installation and updates

4. Console warnings: The main purpose was to avoid console warnings, which are now handled differently

5. Simplification: Removing unnecessary features makes the bundle easier to maintain

What It Used To Do

When enabled, this option would:

• Create a Workbox caching strategy for the manifest URL

• Use the StaleWhileRevalidate strategy

• Cache the manifest file in the service worker cache

• Serve cached manifest on subsequent loads

Alternatives

If you need to cache your manifest file, you have several options:

1. Standard HTTP Caching (Recommended)

Configure your web server to cache the manifest file using HTTP headers:

Nginx:

location /manifest.json {
    add_header Cache-Control "public, max-age=3600";
}

Apache (.htaccess):

<Files "manifest.json">
    Header set Cache-Control "public, max-age=3600"
</Files>

2. Custom Resource Cache

Add the manifest to a custom resource cache strategy:

/config/packages/pwa.yaml

pwa:
    serviceworker:
        workbox:
            resource_caches:
                - match_callback: '({url}) => url.pathname === "/manifest.json"'
                  strategy: 'StaleWhileRevalidate'
                  cache_name: 'manifest'
                  max_age: 1 hour

3. Browser Default Behavior

Simply rely on browser caching - modern browsers efficiently cache small JSON files like manifests without requiring service worker intervention.

Migration Guide

If your configuration includes cache_manifest, you can:

1. Remove the option - It has no effect, but removing it keeps your configuration clean:

   pwa:
       serviceworker:
           workbox:
               # cache_manifest: true  ← Remove this line

2. Keep the option - It won't cause errors, but it won't do anything either

3. Use HTTP caching - Configure your web server for better performance (recommended)

No Action Required: Removing this option from your configuration has no impact on your PWA functionality. The manifest will continue to work exactly as before.

Related Documentation

• Resource Caching - Custom caching strategies for any resource

• Cache Management - Managing service worker caches

• Configuration - Complete service worker configuration reference