Advanced Usage

caution

You are reading documentation for an outdated version. Here’s the latest one!

Documentation for latest release

The documentation listed here is for Version 2 of the JavaScript Tracker. Version 3 is now available and upgrading is recommended.

- Documentation for Version 3

- v2 to v3 Migration Guide

This section covers the more advanced elements of the JavaScript Tracker.

📄️ Optional timestamp argument

Since 2.7.0 each track...() method supports an optional timestamp as its final argument; this allows you to manually override the timestamp attached to this event. The timestamp should be in milliseconds since the Unix epoch.

📄️ Tracker Callbacks

If you call snowplow with a function as the argument, the function will be executed when sp.js loads:

📄️ Getting the most out of performance timing

The domComplete, loadEventStart, and loadEventEnd metrics in the NavigationTiming API are set to 0 until after every script on the page has finished executing, including sp.js. This means that the corresponding fields in the PerformanceTiming reported by the tracker will be 0. To get around this limitation, you can wrap all Snowplow code in a setTimeout call: