Custom Cache Strategies

The bundle provides a comprehensive set of cache strategies through configuration. However, for advanced use cases requiring specific behaviors not covered by the YAML configuration, you can create custom cache strategies programmatically.

When to Use Custom Strategies

Use custom cache strategies when you need:

• Dynamic behavior: Cache strategies that change based on runtime conditions

• Complex matching logic: URL patterns too complex for regex or simple callbacks

• Custom plugins: Workbox plugins with specific configuration

• Conditional caching: Different strategies based on user state, headers, or other factors

• Business logic integration: Caching tied to your application's domain logic

For most use cases, the YAML configuration and resource caching are sufficient.

Quick Start: Using WorkboxCacheStrategy

The easiest way to create custom cache strategies is using the WorkboxCacheStrategy helper class:

src/Service/MyCustomCacheStrategies.php

<?php

declare(strict_types=1);

namespace App\Service;

use SpomkyLabs\PwaBundle\CachingStrategy\CacheStrategyInterface;
use SpomkyLabs\PwaBundle\CachingStrategy\HasCacheStrategiesInterface;
use SpomkyLabs\PwaBundle\CachingStrategy\WorkboxCacheStrategy;
use SpomkyLabs\PwaBundle\WorkboxPlugin\ExpirationPlugin;

final readonly class MyCustomCacheStrategies implements HasCacheStrategiesInterface
{
    /**
     * @return array<CacheStrategyInterface>
     */
    public function getCacheStrategies(): array
    {
        return [
            // CacheFirst strategy for API data
            WorkboxCacheStrategy::create(
                enabled: true,
                requireWorkbox: true,
                strategy: CacheStrategyInterface::STRATEGY_CACHE_FIRST,
                matchCallback: '({url}) => url.pathname.startsWith("/api/static/")',
            )
                ->withName('api-static-data')
                ->withPlugin(
                    ExpirationPlugin::create(
                        maxEntries: 50,
                        maxAgeSeconds: 86400, // 1 day
                    )
                ),
        ];
    }
}

With service autoconfiguration enabled (default in Symfony), the tag spomky_labs_pwa.cache_strategy is added automatically. Otherwise, you need to tag your service manually.

Complete Example: Multiple Strategies

A comprehensive example showing various cache strategies with different configurations:

src/Service/AdvancedCacheStrategies.php

<?php

declare(strict_types=1);

namespace App\Service;

use SpomkyLabs\PwaBundle\CachingStrategy\CacheStrategyInterface;
use SpomkyLabs\PwaBundle\CachingStrategy\HasCacheStrategiesInterface;
use SpomkyLabs\PwaBundle\CachingStrategy\WorkboxCacheStrategy;
use SpomkyLabs\PwaBundle\WorkboxPlugin\ExpirationPlugin;
use SpomkyLabs\PwaBundle\WorkboxPlugin\CacheableResponsePlugin;
use SpomkyLabs\PwaBundle\WorkboxPlugin\BroadcastUpdatePlugin;

final readonly class AdvancedCacheStrategies implements HasCacheStrategiesInterface
{
    /**
     * @return array<CacheStrategyInterface>
     */
    public function getCacheStrategies(): array
    {
        return [
            // 1. Admin API - NetworkFirst with short cache
            $this->createAdminApiStrategy(),

            // 2. User-generated content - StaleWhileRevalidate with broadcast
            $this->createUserContentStrategy(),

            // 3. External CDN resources - CacheFirst with long expiration
            $this->createCdnStrategy(),

            // 4. Search results - NetworkFirst with tight cache
            $this->createSearchStrategy(),
        ];
    }

    private function createAdminApiStrategy(): CacheStrategyInterface
    {
        return WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_NETWORK_FIRST,
            matchCallback: '({url}) => url.pathname.startsWith("/admin/api/")',
        )
            ->withName('admin-api')
            ->withMethod('POST')  // Only intercept POST requests
            ->withOptions(['networkTimeoutSeconds' => 2])
            ->withPlugin(
                // Only cache successful responses
                CacheableResponsePlugin::create(statuses: [200]),
                // Short cache duration
                ExpirationPlugin::create(
                    maxEntries: 20,
                    maxAgeSeconds: 300, // 5 minutes
                )
            );
    }

    private function createUserContentStrategy(): CacheStrategyInterface
    {
        return WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_STALE_WHILE_REVALIDATE,
            matchCallback: 'regex: /\\/user\\/[0-9]+\\/profile/',
        )
            ->withName('user-profiles')
            ->withPlugin(
                // Notify clients when cache updates
                BroadcastUpdatePlugin::create([
                    'Content-Type',
                    'ETag',
                    'Last-Modified',
                ]),
                // Cache valid responses
                CacheableResponsePlugin::create(statuses: [0, 200]),
                // Reasonable expiration
                ExpirationPlugin::create(
                    maxEntries: 100,
                    maxAgeSeconds: 3600, // 1 hour
                )
            );
    }

    private function createCdnStrategy(): CacheStrategyInterface
    {
        return WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_CACHE_FIRST,
            matchCallback: 'origin: https://cdn.example.com',
        )
            ->withName('external-cdn')
            ->withPlugin(
                CacheableResponsePlugin::create(statuses: [0, 200]),
                ExpirationPlugin::create(
                    maxEntries: 200,
                    maxAgeSeconds: 2592000, // 30 days
                )
            );
    }

    private function createSearchStrategy(): CacheStrategyInterface
    {
        return WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_NETWORK_FIRST,
            matchCallback: '({url}) => url.pathname === "/search" && url.searchParams.has("q")',
        )
            ->withName('search-results')
            ->withOptions(['networkTimeoutSeconds' => 3])
            ->withPlugin(
                CacheableResponsePlugin::create(statuses: [200]),
                ExpirationPlugin::create(
                    maxEntries: 30,
                    maxAgeSeconds: 600, // 10 minutes
                )
            );
    }
}

WorkboxCacheStrategy API

The WorkboxCacheStrategy class provides a fluent interface for building cache strategies:

create()

Create a new strategy instance:

WorkboxCacheStrategy::create(
    enabled: true,              // Enable/disable this strategy
    requireWorkbox: true,       // Whether Workbox is required
    strategy: string,           // One of the 5 Workbox strategies
    matchCallback: string,      // URL matching pattern or callback
)

Available strategies:

• CacheStrategyInterface::STRATEGY_CACHE_FIRST - Cache first, fallback to network

• CacheStrategyInterface::STRATEGY_NETWORK_FIRST - Network first, fallback to cache

• CacheStrategyInterface::STRATEGY_STALE_WHILE_REVALIDATE - Cache immediately, update in background

• CacheStrategyInterface::STRATEGY_CACHE_ONLY - Cache only, never network

• CacheStrategyInterface::STRATEGY_NETWORK_ONLY - Network only, never cache

withName()

Set a custom cache name:

->withName('my-custom-cache')

withMethod()

Specify HTTP method to intercept (default: all methods):

->withMethod('POST')  // Only POST requests
->withMethod('GET')   // Only GET requests

withPlugin()

Add Workbox plugins to customize behavior:

->withPlugin(
    ExpirationPlugin::create(maxEntries: 50, maxAgeSeconds: 3600),
    CacheableResponsePlugin::create(statuses: [200])
)

withPreloadUrl()

Precache specific URLs when service worker installs:

->withPreloadUrl('/critical-page', '/important-data.json')

withOptions()

Set additional Workbox options:

->withOptions([
    'networkTimeoutSeconds' => 3,  // For NetworkFirst/NetworkOnly
])

Available Workbox Plugins

ExpirationPlugin

Automatically remove old cache entries:

use SpomkyLabs\PwaBundle\WorkboxPlugin\ExpirationPlugin;

ExpirationPlugin::create(
    maxEntries: 50,        // Max number of entries
    maxAgeSeconds: 86400,  // Max age (1 day)
)

CacheableResponsePlugin

Control which responses get cached:

use SpomkyLabs\PwaBundle\WorkboxPlugin\CacheableResponsePlugin;

// Cache only successful responses
CacheableResponsePlugin::create(statuses: [200])

// Cache successful and opaque responses
CacheableResponsePlugin::create(statuses: [0, 200])

// Cache based on headers
CacheableResponsePlugin::create(
    statuses: [200],
    headers: ['X-Is-Cacheable' => 'true']
)

BroadcastUpdatePlugin

Notify clients when cached data updates:

use SpomkyLabs\PwaBundle\WorkboxPlugin\BroadcastUpdatePlugin;

// Default headers
BroadcastUpdatePlugin::create()

// Custom headers to check
BroadcastUpdatePlugin::create([
    'Content-Type',
    'ETag',
    'Last-Modified',
    'X-Custom-Version',
])

Listen for updates in your application:

// In your frontend code
const channel = new BroadcastChannel('workbox');
channel.addEventListener('message', (event) => {
    if (event.data.type === 'CACHE_UPDATED') {
        console.log('Cache updated:', event.data);
        // Reload data or notify user
    }
});

BackgroundSyncPlugin

Queue failed requests for retry when online:

use SpomkyLabs\PwaBundle\WorkboxPlugin\BackgroundSyncPlugin;

BackgroundSyncPlugin::create(
    queueName: 'api-queue',
    maxRetentionTime: 2880,      // 2 days in minutes
    forceSyncFallback: false,
    broadcastChannel: 'sync-updates',
)

Match Callback Patterns

The matchCallback parameter supports several formats:

1. Path Prefix

matchCallback: 'startsWith: /api/'

2. Regular Expression

matchCallback: 'regex: /\\/product\\/[0-9]+/'

3. Origin Match

matchCallback: 'origin: https://api.example.com'

4. Custom JavaScript Callback

matchCallback: '({url, request}) => url.pathname.endsWith(".json") && request.method === "GET"'

5. Special Keywords

matchCallback: 'navigate'  // Navigation requests (page loads)

Advanced Example: Conditional Strategy

Create strategies that adapt based on conditions:

src/Service/ConditionalCacheStrategy.php

<?php

declare(strict_types=1);

namespace App\Service;

use SpomkyLabs\PwaBundle\CachingStrategy\CacheStrategyInterface;
use SpomkyLabs\PwaBundle\CachingStrategy\HasCacheStrategiesInterface;
use SpomkyLabs\PwaBundle\CachingStrategy\WorkboxCacheStrategy;
use SpomkyLabs\PwaBundle\WorkboxPlugin\ExpirationPlugin;
use Symfony\Component\DependencyInjection\Attribute\Autowire;

final readonly class ConditionalCacheStrategy implements HasCacheStrategiesInterface
{
    public function __construct(
        #[Autowire(param: 'kernel.environment')]
        private string $environment,
        #[Autowire(param: 'kernel.debug')]
        private bool $debug,
    ) {
    }

    public function getCacheStrategies(): array
    {
        $strategies = [];

        // Different strategies for production vs development
        if ($this->environment === 'prod') {
            // Aggressive caching in production
            $strategies[] = WorkboxCacheStrategy::create(
                enabled: true,
                requireWorkbox: true,
                strategy: CacheStrategyInterface::STRATEGY_CACHE_FIRST,
                matchCallback: '({url}) => url.pathname.startsWith("/static/")',
            )
                ->withName('static-production')
                ->withPlugin(
                    ExpirationPlugin::create(
                        maxEntries: 200,
                        maxAgeSeconds: 2592000, // 30 days
                    )
                );
        } else {
            // Minimal caching in development
            $strategies[] = WorkboxCacheStrategy::create(
                enabled: true,
                requireWorkbox: true,
                strategy: CacheStrategyInterface::STRATEGY_NETWORK_FIRST,
                matchCallback: '({url}) => url.pathname.startsWith("/static/")',
            )
                ->withName('static-development')
                ->withOptions(['networkTimeoutSeconds' => 1])
                ->withPlugin(
                    ExpirationPlugin::create(
                        maxEntries: 10,
                        maxAgeSeconds: 60, // 1 minute
                    )
                );
        }

        return $strategies;
    }
}

Real-World Use Cases

Use Case 1: Multi-tenant Application

Different caching for each tenant:

public function getCacheStrategies(): array
{
    // Assuming tenant ID is in URL like /tenant/123/...
    return [
        WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_NETWORK_FIRST,
            matchCallback: '({url}) => /\/tenant\/[0-9]+\/data/.test(url.pathname)',
        )
            ->withName('tenant-data')
            ->withPlugin(
                ExpirationPlugin::create(
                    maxEntries: 100,
                    maxAgeSeconds: 1800, // 30 minutes
                )
            ),
    ];
}

Use Case 2: Authenticated API with Token Refresh

Cache API calls but refresh when needed:

public function getCacheStrategies(): array
{
    return [
        WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_NETWORK_FIRST,
            matchCallback: <<<'JS'
({url, request}) => {
    return url.pathname.startsWith('/api/') &&
           request.headers.has('Authorization');
}
JS,
        )
            ->withName('authenticated-api')
            ->withMethod('GET')
            ->withOptions(['networkTimeoutSeconds' => 2])
            ->withPlugin(
                // Only cache successful responses
                CacheableResponsePlugin::create(statuses: [200]),
                // Notify on updates for real-time sync
                BroadcastUpdatePlugin::create(),
                // Short cache duration
                ExpirationPlugin::create(
                    maxEntries: 50,
                    maxAgeSeconds: 300,
                )
            ),
    ];
}

Use Case 3: Versioned API Endpoints

Different strategies for stable vs unstable API versions:

public function getCacheStrategies(): array
{
    return [
        // Stable API (v1) - aggressive caching
        WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_CACHE_FIRST,
            matchCallback: '({url}) => url.pathname.startsWith("/api/v1/")',
        )
            ->withName('api-v1-stable')
            ->withPlugin(
                ExpirationPlugin::create(
                    maxEntries: 100,
                    maxAgeSeconds: 86400, // 1 day
                )
            ),

        // Beta API (v2) - fresh data
        WorkboxCacheStrategy::create(
            enabled: true,
            requireWorkbox: true,
            strategy: CacheStrategyInterface::STRATEGY_NETWORK_FIRST,
            matchCallback: '({url}) => url.pathname.startsWith("/api/v2/")',
        )
            ->withName('api-v2-beta')
            ->withOptions(['networkTimeoutSeconds' => 2])
            ->withPlugin(
                ExpirationPlugin::create(
                    maxEntries: 30,
                    maxAgeSeconds: 300, // 5 minutes
                )
            ),
    ];
}

Implementing Custom Strategy Interface

For complete control, implement CacheStrategyInterface directly:

src/Service/CustomJavaScriptStrategy.php

<?php

declare(strict_types=1);

namespace App\Service;

use SpomkyLabs\PwaBundle\CachingStrategy\CacheStrategyInterface;

final class CustomJavaScriptStrategy implements CacheStrategyInterface
{
    public function getName(): ?string
    {
        return 'my-custom-strategy';
    }

    public function isEnabled(): bool
    {
        return true;
    }

    public function needsWorkbox(): bool
    {
        return false;  // Standalone JavaScript
    }

    public function render(string $cacheObjectName, bool $debug = false): string
    {
        // Return raw JavaScript that will be injected into service worker
        return <<<'JS'
// Custom cache strategy with pure JavaScript
self.addEventListener('fetch', (event) => {
    if (event.request.url.includes('/custom/')) {
        event.respondWith(
            caches.match(event.request).then((cachedResponse) => {
                if (cachedResponse) {
                    // Custom logic: fetch in background if cached
                    fetch(event.request).then((response) => {
                        caches.open('custom-cache').then((cache) => {
                            cache.put(event.request, response);
                        });
                    });
                    return cachedResponse;
                }
                return fetch(event.request);
            })
        );
    }
});
JS;
    }
}

When implementing the full interface, you're responsible for all JavaScript generation. This approach is powerful but requires careful testing.

Service Registration

If service autoconfiguration is disabled, register your service manually:

config/services.yaml

services:
    App\Service\MyCustomCacheStrategies:
        tags:
            - { name: 'spomky_labs_pwa.cache_strategy' }

Debugging Custom Strategies

1. Check Generated Service Worker

View the compiled service worker at /sw.js (or your configured dest) to see the generated JavaScript:

curl https://your-app.com/sw.js

2. Enable Debug Mode

Set kernel.debug: true to get commented JavaScript output:

# config/packages/pwa.yaml
pwa:
    serviceworker:
        workbox:
            enabled: true

When debug is enabled, the generated code includes comments:

/**************************************************** CACHE STRATEGY ****************************************************/
// Strategy: NetworkFirst
// Match: ({url}) => url.pathname.startsWith("/api/")
// Cache Name: admin-api
// ...

3. Chrome DevTools

1. Open DevTools (F12)

2. Go to Application → Service Workers

3. Click "Update" to reload service worker

4. Check Application → Cache Storage to see your custom caches

5. Use Network tab with "Offline" to test cache behavior

Best Practices

1. Start with YAML configuration: Only use custom strategies when necessary

2. Use descriptive names: Make cache names clear (e.g., api-user-data not cache1)

3. Set appropriate limits: Configure maxEntries and maxAgeSeconds to prevent cache bloat

4. Test offline: Verify strategies work correctly without network

5. Monitor cache size: Check DevTools → Storage to ensure caches don't grow too large

6. Use typed callbacks: TypeScript-style types help prevent errors in matchCallback

7. Document complex logic: Add comments explaining why custom strategies exist

Related Documentation

• Configuration Reference - Standard YAML configuration

• Resource Caching - Configure caching via YAML

• Workbox Strategies - Official Workbox docs

• Custom Service Worker Rules - Advanced service worker customization