Question
I'm developing for Tizen 3.0 Smart TV and trying to cache some images and JavaScript files using HTML5 Application Cache. My test setup includes:
- demo.appcache file:
CACHE MANIFEST
#VERSION 1.0.0
CACHE:
cache_test.js
- index.html:
<!DOCTYPE html>
<html manifest="demo.appcache">
<head>
<title>APPCACHE TEST</title>
</head>
<body>
<script src="cache_test.js"></script>
</body>
</html>
However, when I run this, the manifest file doesn't seem to be linked properly. When I try to execute applicationCache.update() from the console, I get the error "there is no application cache to update."
Could you provide guidance on implementing application cache correctly in Tizen Smart TV applications?
Answer
Problem Understanding
The issue occurs when the application cache manifest isn't being properly recognized by the Tizen browser. This could be due to:
- Incorrect file paths in the manifest
- Missing MIME type configuration
- Browser-specific implementation differences
Solution Methods
-
Path Correction:
- Update the manifest file to use explicit paths:
CACHE MANIFEST #VERSION 1.0.0 CACHE: ./cache_test.js
- Update the manifest file to use explicit paths:
-
Cache Status Verification:
- Check the current cache status using this JavaScript code:
var appCache = window.applicationCache; switch (appCache.status) { case appCache.UNCACHED: // 0 console.log('UNCACHED'); break; case appCache.IDLE: // 1 console.log('IDLE'); break; case appCache.CHECKING: // 2 console.log('CHECKING'); break; case appCache.DOWNLOADING: // 3 console.log('DOWNLOADING'); break; case appCache.UPDATEREADY: // 4 console.log('UPDATEREADY'); break; case appCache.OBSOLETE: // 5 console.log('OBSOLETE'); break; default: console.log('UNKNOWN CACHE STATUS'); }
- Check the current cache status using this JavaScript code:
Additional Tips
- Ensure your web server serves the .appcache file with the correct MIME type:
text/cache-manifest - Remember that
applicationCache.update()is used to re-download cached data, not for initial cache setup - Consider using Service Workers as a more modern alternative to Application Cache, as it's being phased out in favor of Service Workers
