At Velocity, we showed Internet Explorer 9 as the first browser to support the W3C Navigation Timing proposal to provide performance information to developers at runtime. This interface is aimed at helping developers measure and understand the performance of their website. Web developers can use this performance information to make their web sites faster. For IE9 Platform Preview 6, we updated the Navigation Timing interface to reflect the latest work of the Web Performance Working Group. Special thanks to Arvind Jain, Steve Souders, Zhiheng Wang, and Tony Gentilcore from Google, Jonas Sicking from Mozilla and Sigbjørn Vik from Opera for their contributions to this work.
With the Web Performance Group members, we’ve been working together to tackle the challenges of providing performance information about page navigations in a way that is standard and interoperable across browsers. Along with providing performance information to help developers tune and optimize their website, we also are conscious of the security implications of providing this information. Together we are working on a design that is valuable to developers and safe for end-users.
Interoperability and making sure the interface works across all browsers and platforms is very important to developers, so they can consistently rely on the results. The W3C Performance Working group is working to evolve the specification from a Working Draft to Recommendation. As progress on the Navigation Timing specification continues, we are updating IE9 to reflect these changes.
New in PPB6
With interoperability in mind, we’ve updated PPB6 to align with the working draft. Thus we removed the interface window.msPerformance.timingMeasures and updated window.msPerformance.timing and window.msPerformance.navigation.
interface MSPerformanceTiming{ readonly attribute unsigned long long navigationStart; readonly attribute unsigned long long unloadEventStart; readonly attribute unsigned long long unloadEventEnd; readonly attribute unsigned long long redirectStart; readonly attribute unsigned long long redirectEnd; readonly attribute unsigned long long fetchStart; readonly attribute unsigned long long domainLookupStart; readonly attribute unsigned long long domainLookupEnd; readonly attribute unsigned long long connectStart; readonly attribute unsigned long long connectEnd; readonly attribute unsigned long long requestStart; readonly attribute unsigned long long responseStart; readonly attribute unsigned long long responseEnd; readonly attribute unsigned long long domLoading; readonly attribute unsigned long long domInteractive; readonly attribute unsigned long long domContentLoaded; readonly attribute unsigned long long domComplete; readonly attribute unsigned long long loadEventStart; readonly attribute unsigned long long loadEventEnd;}interface MSPerformanceNavigation{ const unsigned short TYPE_NAVIGATE = 0; const unsigned short TYPE_RELOAD = 1; const unsigned short TYPE_BACK_FORWARD = 2; const unsigned short TYPE_RESERVED = 255; readonly attribute unsigned long long type; readonly attribute unsigned long long redirectCount;}Give it a Test Drive!
In Platform Preview 6, you’ll find that the interface aligns closer to the latest Navigation Timing Specification. You can try this out for yourself with the window.msPerformance Test Drive demo.
As the working group stabilizes Navigation Timing specification, we expect fewer changes to the IE implementation. We encourage you to try this interface and we welcome your feedback. Please give the Navigation Timing interface a test drive.
Anderson Quach
Program Manager
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