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Boomerang Howto #9: Collect performance data from the Navigation Timing API

The W3C Navigation Timing API is an interface implemented by modern browsers that provides broad and deep data related to the performance of page loads. At the time of this writing, it is supported by the following browsers:

Chrome 6+
Internet Explorer 9+
Firefox 7+ (note that a bug in Firefox 7 and 8 reports the incorrect time for navigationStart. Use unloadEventStart or fetchStart for a close proximation.)

The navtiming.js plugin doesn't require any configuration options as it simply reads data out of the browser (if available) and adds it to the beacon query string.

You will have to build your own version of boomerang.js since it isn't one of the default plugins. To do this, run make in the boomerang directory with the following option:

make PLUGINS=navtiming.js

Then you can include the new boomerang file (don't forget to run it through your favorite Javascript minifier first) as you normally would.

The new query parameters and the browser attributes they map to are shown below. More information about the definition of each attribute can be found in the W3C Navigation Timing specification.

Boomerang beacon parameter	Navigation Timing attribute
`nt_red_cnt`	`window.performance.navigation.redirectCount`
`nt_nav_type`	`window.performance.navigation.type`
`nt_nav_st`	`window.performance.timing.navigationStart`
`nt_red_st`	`window.performance.timing.redirectStart`
`nt_red_end`	`window.performance.timing.redirectEnd`
`nt_fet_st`	`window.performance.timing.fetchStart`
`nt_dns_st`	`window.performance.timing.domainLookupStart`
`nt_dns_end`	`window.performance.timing.domainLookupEnd`
`nt_con_st`	`window.performance.timing.connectStart`
`nt_con_end`	`window.performance.timing.connectEnd`
`nt_req_st`	`window.performance.timing.requestStart`
`nt_res_st`	`window.performance.timing.responseStart`
`nt_res_end`	`window.performance.timing.responseEnd`
`nt_domloading`	`window.performance.timing.domLoading`
`nt_domint`	`window.performance.timing.domInteractive`
`nt_domcontloaded_st`	`window.performance.timing.domContentLoadedStart`
`nt_domcontloaded_end`	`window.performance.timing.domContentLoadedEnd`
`nt_domcomp`	`window.performance.timing.domComplete`
`nt_load_st`	`window.performance.timing.loadEventStart`
`nt_load_end`	`window.performance.timing.loadEventEnd`
`nt_unload_st`	`window.performance.timing.unloadEventStart`
`nt_unload_end`	`window.performance.timing.unloadEventEnd`

The latest code and docs is available on github.com/lognormal/boomerang