Let’s face it AppCache is annoying and has problems [ 1 2 3 ] One big limitation is the fact that it’s impossible to dynamically cache assets on demand Essentially this makes it an all or nothing thing when it comes to taking an app offline Either everything in the manifest is cached up front or nothing is cached

The HTML5 FileSystem API becomes an attractive solution for AppCache’s shortcomings One can programmatically store files and folder hierarchies in the local (sandboxed) filesystem and subsequently add/update/remove individual resources as necessary My colleague…..

Creating a nice CSS layout starts with assigning sizes for all the things being placed in a web application One highly requested feature has always been the ability to specify sizes using a mixture of sizing units For example it’d be nice to be able to reserve 50% of an area plus a fixed amount of space say 10px Well you can do that right now using the calc() property You can use this feature anywhere a length or number is used so you can use it for positioning things or in rgb() color values…..

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JavaScript is relatively fast but it can always go faster Read more about how to optimize your JavaScript for performance

How to write low garbage real-time JavaScript from Scirra the HTML5 game making tool

Optimizing for V8 – Introduction is written by Florian Loitsch engineer on Dart’s JavaScript generation

Optimizing for V8 – Inling Deoptimizations is part 2 in Florian’s series

From Console to Chrome – HTML5 and JavaScript for game developers from Lilli Thompson Chrome Games engineer …..

Chromium recently implemented a new feature from HTML5: scoped stylesheets aka <style scoped> A web author can limit style rules to only apply to a part of a page by setting the ‘scoped’ attribute on a <style> element that is the direct child of the root element of the subtree you want the styles to be applied to This limits the styles to affect just the element that is the parent of the <style> element and all of its descendants

Example

Here’s a simple document that uses standard styling:

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Chromium recently implemented a new feature from HTML5: scoped stylesheets aka <style scoped> A web author can limit style rules to only apply to a part of a page by setting the ‘scoped’ attribute on a <style> element that is the direct child of the root element of the subtree you want the styles to be applied to This limits the styles to affect just the element that is the parent of the <style> element and all of its descendants

Example

Here’s a simple document that uses standard styling:

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