Custom Cache Strategy

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 [
            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

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\BroadcastUpdatePlugin;
use SpomkyLabs\PwaBundle\WorkboxPlugin\CacheableResponsePlugin;
use SpomkyLabs\PwaBundle\WorkboxPlugin\ExpirationPlugin;

final readonly class AdvancedCacheStrategies implements HasCacheStrategiesInterface
{
    /**
     * @return array<CacheStrategyInterface>
     */
    public function getCacheStrategies(): array
    {
        return [
            $this->createAdminApiStrategy(),
            $this->createUserContentStrategy(),
            $this->createCdnStrategy(),
        ];
    }

    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')
            ->withOptions(['networkTimeoutSeconds' => 2])
            ->withPlugin(
                CacheableResponsePlugin::create(statuses: [200]),
                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(
                BroadcastUpdatePlugin::create([
                    'Content-Type',
                    'ETag',
                    'Last-Modified',
                ]),
                CacheableResponsePlugin::create(statuses: [0, 200]),
                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
                ),
            );
    }
}

WorkboxCacheStrategy API

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

Fluent Methods

Method	Description
withName(string)	Set a custom cache name
withMethod(string)	Specify HTTP method to intercept (e.g., 'POST', 'GET')
withPlugin(CachePluginInterface, ...)	Add one or more Workbox plugins
withPreloadUrl(string, ...)	Precache specific URLs on service worker install
withOptions(array)	Set additional Workbox options (e.g., networkTimeoutSeconds)

Available Workbox Plugins

ExpirationPlugin

Automatically remove old cache entries:

use SpomkyLabs\PwaBundle\WorkboxPlugin\ExpirationPlugin;

ExpirationPlugin::create(
    maxEntries: 50,
    maxAgeSeconds: 86400, // 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])

BroadcastUpdatePlugin

Notify clients when cached data updates:

use SpomkyLabs\PwaBundle\WorkboxPlugin\BroadcastUpdatePlugin;

BroadcastUpdatePlugin::create([
    'Content-Type',
    'ETag',
    'Last-Modified',
])

Listen for updates in your application:

const channel = new BroadcastChannel('workbox');
channel.addEventListener('message', (event) => {
    if (event.data.type === 'CACHE_UPDATED') {
        console.log('Cache updated:', event.data);
    }
});

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',
)

RangeRequestsPlugin

Support HTTP range requests for large files:

use SpomkyLabs\PwaBundle\WorkboxPlugin\RangeRequestsPlugin;

RangeRequestsPlugin::create()

Match Callback Patterns

The matchCallback parameter supports several formats:

Path Prefix

matchCallback: 'startsWith: /api/'

Regular Expression

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

Origin Match

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

Custom JavaScript Callback

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

Navigation Requests

matchCallback: 'navigate'

Conditional Strategies

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,
    ) {
    }

    public function getCacheStrategies(): array
    {
        if ($this->environment === 'prod') {
            return [
                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)
                    ),
            ];
        }

        return [
            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)
                ),
        ];
    }
}

Implementing CacheStrategyInterface Directly

For complete control, implement CacheStrategyInterface directly to generate raw JavaScript:

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 <<<'JS'
self.addEventListener('fetch', (event) => {
    if (event.request.url.includes('/custom/')) {
        event.respondWith(
            caches.match(event.request).then((cachedResponse) => {
                if (cachedResponse) {
                    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' }

Listing Cache Strategies

Use the console command to list all registered cache strategies:

php bin/console pwa:cache:list

This displays all strategies (from YAML config and custom services) with their configuration details.

Debugging

Check Generated Service Worker

View the compiled service worker to see the generated JavaScript:

php bin/console pwa:compile
# Then inspect the generated sw.js file

When debug is enabled, the generated code includes comments explaining each strategy.

Chrome DevTools

1. Open DevTools (F12) → Application → Service Workers
2. Click "Update" to reload service worker
3. Check Application → Cache Storage to see your custom caches
4. 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. Document complex logic: Add comments explaining why custom strategies exist

Related Documentation

• Service Worker Configuration - Standard YAML configuration
• Resource Caching - Configure caching via YAML
• Custom Service Worker Rules - Advanced service worker customization