Blog

What to Expect in Ext JS 4.1

August 11, 2011 | Aditya Bansod

We’ve been hard at work on Ext JS; both working on bug fixes and improvements in 4.0.x as well as in 4.1. The first beta of 4.1 is around the corner so wanted to share the details of what to expect in Ext JS 4.1.

In talking with the community, we heard loud and clear the two areas we needed to spend the most time: performance and documentation. Indeed that has been our focus for 4.1. Let’s look at each of them individually.

Performance

Many of you rely on Ext JS for your mission critical projects, which are often highly complex apps with hundreds of layouts, views and configurations. We’ve found that for certain classes of applications, Ext JS 4.0.x could be a lot faster in how it deals with the DOM. Specifically, for applications that have complex layouts, Ext JS 4.0.x reads and writes to the DOM frequently causing latency in the layout process. In Ext JS 4.1 we’ve changed this to be far less ‘chatty’. Instead of re-reading and re-writing the DOM during the entire layout process, 4.1 will now buffer and batch reads and writes.

We’ve also made further changes in the component rendering: instead of each component rendering itself directly to the DOM, its writes are now batched up into a single DOM insert per top-level container, which means that any app using a Viewport will have all of its components rendered in a single DOM write. This should significantly increase the performance of both simple and complex layouts across browsers.

In addition to the new DOM management strategy, Ext JS 4.1 also speeds up component rendering. In 4.0.x, when a component was rendered we used CSS selectors to find elements. We’ve updated that to use IDs, which are faster when performing a component layout. We have also updated the Grid component to use browser-native scrollbars and have moved away from virtualized scrolling. This offers two significant benefits. First, the grid scrolls faster and offers a more ‘browser-native’ scrolling feel. Second, for Mac OS X Lion users, the scrolling behavior is now Lion-compatible.

Not specifically performance related, we’ve also fixed bugs across the board that have been reported in our forums, through our support channels, as well as through customer conversations. We’ve fixed bugs in the data package (making sure esoteric combinations of proxies, readers and writers work as expected), the charting package (performance and edge case improvements). We’re also hoping to reintroduce the Calendar component with 4.1.

You’ll also notice in the Ext JS Forums, bugs that have been linked to our internal bug reporting system now show the issue number so we can better track and respond to community issues.

Many of these fixes are already available to support subscribers and we’ll be happy to make them publicly available when Ext JS 4.1 ships.

Documentation

The documentation tool that was released with Ext JS 4.0 provided a fresh new look at all the documentation that Ext JS had to offer. While documentation is never done, we’ve spent a good amount of improving two areas of the docs: the actual docs, as well as the doc tool. In 4.1 we’ll be including new content as well as refreshes to the existing content for clarity and consistency. The upgrades we’ll be making to the docs tool will make it easier to navigate and explore the content and allow it to become a better reference guide for working on Ext JS. We’ll be sharing more details about documentation in a blog post next week.

When to Expect Ext JS 4.1

We’re looking to deliver the first beta of Ext JS 4.1 in mid to late September. While that may feel like some time from now, the overhaul of the layout mechanics have required a significant amount of engineering and testing and we want to ensure that we work through as many of the ‘gotchas’ as possible so our community doesn’t have to.

Ext JS 4.0 introduced a huge number of new features, but also turned out to have some performance and documentation holes and we hope that Ext JS 4.1 solves as many issues and concerns that you’ve had. Also, we originally had RTL and ARIA support scheduled for 4.1, but with the emphasis on performance improvements for 4.1, we’ve had to push these features out to a 4.2 release. We can never thank you enough for all the help and attention you give to Ext JS, whether it’s through reports on the forums, conversations on Twitter, finding us at conferences, or wherever. We’re committed to making Ext JS hands-down the best choice for desktop web application projects!