---
url: /api/symbols/workbox-swkit/precaching/precachecontroller.md
---

# PrecacheController

Class @vite-pwa/workbox-swkit/precaching

Performs efficient precaching of assets.

## Constructor

```ts
new PrecacheController(options?: PrecacheControllerOptions)
```

Create a new PrecacheController.

## Methods

### activate()

```ts
activate(event: ExtendableEvent): Promise<CleanupResult>
```

Deletes assets that are no longer present in the current precache manifest.
Call this method from the service worker activate event.

Note: this method calls `event.waitUntil()` for you, so you do not need
to call it yourself in your event handlers.

**Returns:**

### addToCacheList()

```ts
addToCacheList(entries: string | PrecacheEntry[]): void
```

This method will add items to the precache list, removing duplicates
and ensuring the information is valid.

**Parameters**

* `entries` – Array of entries to precache.

### createHandlerBoundToURL()

```ts
createHandlerBoundToURL(url: string): RouteHandlerCallback
```

Returns a function that looks up `url` in the precache (taking into
account revision information), and returns the corresponding `Response`.

**Parameters**

* `url` – The precached URL which will be used to lookup the
  `Response`.

**Returns:**

### getCachedURLs()

```ts
getCachedURLs(): string[]
```

Returns a list of all the URLs that have been precached by the current
service worker.

**Returns:** The precached URLs.

### getCacheKeyForURL()

```ts
getCacheKeyForURL(url: string): string | undefined
```

Returns the cache key used for storing a given URL. If that URL is
unversioned, like \`/index.html', then the cache key will be the original
URL with a search parameter appended to it.

**Parameters**

* `url` – A URL whose cache key you want to look up.

**Returns:** The versioned URL that corresponds to a cache key
for the original URL, or undefined if that URL isn't precached.

### getIntegrityForCacheKey()

```ts
getIntegrityForCacheKey(cacheKey: string): string | undefined
```

**Parameters**

* `cacheKey` – A cache key whose SRI you want to look up.

**Returns:** The subresource integrity associated with the cache key,
or undefined if it's not set.

### getURLsToCacheKeys()

```ts
getURLsToCacheKeys(): Map<string, string>
```

Returns a mapping of a precached URL to the corresponding cache key, taking
into account the revision information for the URL.

**Returns:** A URL to cache key mapping.

### install()

```ts
install(event: ExtendableEvent): Promise<InstallResult>
```

Precaches new and updated assets. Call this method from the service worker
install event.

Note: this method calls `event.waitUntil()` for you, so you do not need
to call it yourself in your event handlers.

**Returns:**

### matchPrecache()

```ts
matchPrecache(request: string | Request): Promise<Response | undefined>
```

This acts as a drop-in replacement for
[`cache.match()`](https://developer.mozilla.org/en-US/docs/Web/API/Cache/match)
with the following differences:

* It knows what the name of the precache is, and only checks in that cache.
* It allows you to pass in an "original" URL without versioning parameters,
  and it will automatically look up the correct cache key for the currently
  active revision of that URL.

E.g., `matchPrecache('index.html')` will find the correct precached
response for the currently active service worker, even if the actual cache
key is `'/index.html?__WB_REVISION__=1234abcd'`.

**Parameters**

* `request` – The key (without revisioning parameters)
  to look up in the precache.

**Returns:**

### precache()

```ts
precache(entries?: string | PrecacheEntry[]): void
```

Adds items to the precache list, removing any duplicates and
stores the files in the
workbox-core.cacheNames|"precache cache" when the service
worker installs.

This method can be called multiple times.

**Parameters**

* `entries` – Array of entries to precache.