HTML5 ApplicationCache

API Summary

window.applicationCache

Supported Platform(s)

Description

Returns the ApplicationCache object that applies to the active document of that Window.

Code Example(s)

<script type="text/javascript">
  var appCache = window.applicationCache;
</script>

worker.applicationCache

Supported Platform(s)

Description

Returns the ApplicationCache object that applies to the current shared applicationCache.

Code Example(s)

<script type="text/javascript">
  var worker = new Worker('doWork.js');
</script>

doWork.js (the worker):

  var appCache = self.applicationCache()

swapCache

Supported Platform(s)

Description

Switches to the most recent application cache, if there is a newer one.
This does not cause previously-loaded resources to be reloaded; for example, images do not suddenly get reloaded and style sheets and scripts do not get reparsed or reevaluated. The only change is that subsequent requests for cached resources will obtain the newer copies.

Code Example(s)

var appCache = window.applicationCache;
appCache.update(); // Attempt to update the user's cache.
...
if (appCache.status == window.applicationCache.UPDATEREADY) {
    appCache.swapCache();  // The fetch was successful, swap in the new cache.
}

update

Supported Platform(s)

Description

Invokes the application cache download process.
Throws an INVALID_STATE_ERR exception if there is no application cache to update.

Code Example(s)

var appCache = window.applicationCache;
appCache.update(); // Attempt to update the user's cache.
...
if (appCache.status == window.applicationCache.UPDATEREADY) {
    appCache.swapCache();  // The fetch was successful, swap in the new cache.
}

cached

Supported Platform(s)

Description

Sent when the resources listed in the manifest have been downloaded, and the application is now cached.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// Fired after the first cache of the manifest.
appCache.addEventListener('cached', handleCacheEvent, false);

checking

Supported Platform(s)

Description

Sent when the cache update process begins.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// Checking for an update. Always the first event fired in the sequence.
appCache.addEventListener('checking', handleCacheEvent, false);

downloading

Supported Platform(s)

Description

Sent when the update process begins downloading resources in the manifest file.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// An update was found. The browser is fetching resources.
appCache.addEventListener('downloading', handleCacheEvent, false);

error

Supported Platform(s)

Description

Sent when an error occurs.

Code Example(s)

function handleCacheErro(e) {
    alert('Error: Cache failed to update!');
};
// The manifest returns 404 or 410, the download failed,
// or the manifest changed while the download was in progress.
appCache.addEventListener('error', handleCacheError, false);

noupdate

Supported Platform(s)

Description

Sent when the update process finishes but the manifest file does not change.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// Fired after the first download of the manifest.
appCache.addEventListener('noupdate', handleCacheEvent, false);

obsolete

Supported Platform(s)

Description

Sent when the manifest was found to have become a 404 or 410 page, so the application cache is being deleted.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// Fired if the manifest file returns a 404 or 410.
// This results in the application cache being deleted
appCache.addEventListener('obsolete', handleCacheEvent, false);

progress

Supported Platform(s)

Description

Sent when each resource in the manifest file begins to download.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// Fired for each resource listed in the manifest as it is being fetched.
appCache.addEventListener('progress', handleCacheEvent, false);

updateready

Supported Platform(s)

Description

Sent when there is an existing application cache, the update process finishes, and there is a new application cache ready for use.

Code Example(s)

function handleCacheEvent(e) {
    //...
}
// Fired when the manifest resources have been newly redownloaded.
appCache.addEventListener('updateready', handleCacheEvent, false);

Properties:

Code Example(s)

var appCache = window.applicationCache;
switch (appCache.status) {
case appCache.UNCACHED:    // UNCACHED == 0
	return 'UNCACHED';
	break;
case appCache.IDLE: 		  // IDLE == 1
	return 'IDLE'; 
	break;
case appCache.CHECKING:    // CHECKING == 2
	return 'CHECKING';
	break;
case appCache.DOWNLOADING: // DOWNLOADING == 3
	return 'DOWNLOADING';
	break;
case appCache.UPDATEREADY: // UPDATEREADY == 5
	return 'UPDATEREADY';
	break;
case appCache.OBSOLETE:    // OBSOLETE == 5
	return 'OBSOLETE';
	break;
default:
	return 'UKNOWN CACHE STATUS';
	break;
};

Constants: