Browser (Javascript) SDK

The Browser SDK makes it easy to track events in webpages.

Installation

The Browser SDK can be installed by loading the Javascript via a script tag, or directly bundled via a npm package.

To install using a script tag, add the following snippet to your site, replacing WRITE_KEY with the write key from your Event Source:

<script type="text/javascript">
!function(){var e=window.htevents=window.htevents||[];if(!e.initialize)if(e.invoked)window.console&&console.error&&console.error("Hightouch snippet included twice.");else{e.invoked=!0,e.methods=["trackSubmit","trackClick","trackLink","trackForm","pageview","identify","reset","group","track","ready","alias","debug","page","once","off","on","addSourceMiddleware","addIntegrationMiddleware","setAnonymousId","addDestinationMiddleware"],e.factory=function(t){return function(){var n=Array.prototype.slice.call(arguments);return n.unshift(t),e.push(n),e}};for(var t=0;t<e.methods.length;t++){var n=e.methods[t];e[n]=e.factory(n)}e.load=function(t,n){var o=document.createElement("script");o.type="text/javascript",o.async=!0,o.src="https://cdn.hightouch-events.com/browser/release/v1-latest/events.min.js";var r=document.getElementsByTagName("script")[0];r.parentNode.insertBefore(o,r),e._loadOptions=n,e._writeKey=t},e.SNIPPET_VERSION="0.0.1",
e.load('WRITE_KEY',{apiHost:'us-east-1.hightouch-events.com'}),
e.page()}}();
</script>

To install using npm:

1. Install the SDK by running npm install @ht-sdks/events-sdk-js-browser
2. Import and initialize the SDK with the following:

import { HtEventsBrowser } from "@ht-sdks/events-sdk-js-browser";
export const htevents = HtEventsBrowser.load(
  { writeKey: "WRITE_KEY" },
  { apiHost: "us-east-1.hightouch-events.com" }
);

API

Identify

The identify method is used to send an identify event.

If identify is called multiple times for the same user, the traits are merged together.

Method signature:

htevents.identify(userId, [traits], [context], [callback])

Method parameters:

Track

The track method is used to send a track event.

Method signature:

htevents.track(event, [properties], [context], [callback])

Method parameters:

Page

The page method is used to send a page event.

Method signature:

htevents.page(category, name, [properties], [context], [callback])

Method parameters:

Group

The group method sends a group event.

Method signature:

htevents.group(groupId, [traits], [context], [callback])

Method parameters:

Reset

The reset method resets the identify and group for the local session. Specifically, it resets the anonymousId, userId, groupId, and traits.

The reset method should be called when users log out. This way, if the user logs back in with another account, the userIds and traits from the different sessions remain separate.

Method signature:

htevents.reset()

Single page applications

While Single Page Apps (SPAs) are great for many reasons, they do require some extra consideration in order to set up client-side tracking than with a traditional webpage.

By default, the Hightouch htevents.js library doesn't generate or store the referrer value. Instead, the referrer value you see in the payload is the value returned by document.referrer directly from the browser, and the URL value is the canonical URL on the page.

When a user navigates between pages on an SPA website, there won't be a referrer because there is no concept of a new page since it's all a single page load. This means that the referrer will always be the same as it was on the first page call where someone was first directed to your site. However, in order to circumvent this, you can manually set the referrer and URL in your Hightouch calls by updating the context object.

For example, a Page call with the referrer and URL manually set looks like this:

htevents.page({
  referrer: 'https://hightouch.com/',
  url: 'https://hightouch.com/pricing/?ref=nav'
})

A Track call with these fields manually updated looks like this:

htevents.track('Example Event', {}, {page: {
  referrer: 'https://hightouch.com/',
  url: 'https://hightouch.com/pricing/?ref=nav'
}})

Tracking emulated page views

Your application should update the URL in the address bar to emulate traditional webpage navigation. Full page requests aren't made in most of these instances since the resources are loaded on initial page load. This means that the Page call in the traditional htevents.js snippet won't fire again as a user navigates around your site.

You should still place the snippet in the head of your site, but you should remove the Page call and fire it whenever you're emulating a page load. Hightouch recommends that you call Page from the same block of logic that updates the view and URL path like below:

// The new view has been called to render
htevents.page("Home")

To track more than the page field, pass those fields in as additional properties. Hightouch recommends that you use variables to set information about page properties, rather than hard-coding. In most SPA frameworks, you can automate this by attaching the Page call to the routing service.

QueryString API

The Browser SDK can trigger track and identify events based on the URL query string. You can use this when tracking email click-throughs, social media clicks, and digital advertising.

Query parameters:

Example

The following URL:

https://hightouch.com/?ajs_uid=123&ajs_event=Clicked%20Email&ajs_aid=abc123&ajs_prop_emailCampaign=First+Touch&ajs_trait_name=John

would result in these calls:

htevents.identify('123', { name: 'John' });
htevents.track('Clicked Email', { 'emailCampaign': 'First Touch' });
htevents.user().anonymousId('abc123');

Configuration

The useQueryString option allows you to control the behavior of the query parameters. For example, you can entirely disable query string processing by setting useQueryString to false:

htevents.load('WRITE_KEY', {
  useQueryString: false
})

You can also keep query string processing on, but enforce validation rules. For example:

htevents.load('WRITE_KEY', {
  useQueryString: {
    // set a pattern for anonymous id
    aid: /([A-Z]{10})/,
    // set a pattern for user id
    uid: /([A-Z]{6})/
  }
})

Cross Domain Tracking

Using the QueryString API you can easily track users across different domains. For example, if you have the following sites:

• Site 1: www.landing-page.com
• Site 2: www.product-page.com

To track a user who starts on Site 1 and navigates to Site 2, you just need to pass the userId from Site 1 to Site 2 using the ajs_uid query parameter.

https://www.product-page.com/?ajs_uid=123

This will automatically trigger an identify event on Site 2 with userId: 123.

If you want to track anonymous users across domains, you can access the anonymousId on Site 1 using:

htevents.user().anonymousId()

You can then pass the anonymousId from Site 1 to Site 2 using the ajs_aid query parameter. Note that the ajs_aid parameter does not automatically trigger an identify event.

Autocollected fields

The browser SDK autocollects the following fields within the context of each event:

Session tracking

A session is a group of "uninterrupted" events that were performed by the same visitor. The session resets once the session's timeout has expired, and automatically refreshes when a new event is sent. For example, if the visitor views a couple pages, and then returns to your site after a day, the next day's events will be considered a new session.

The browser SDK automatically tracks a sessionId field to track what events occurred in the same session. If two events occured in the same session, they will have the same session ID.

The session timeout can be adjusted from the default of 30 minutes when the SDK is initialized:

e.load('YOUR_WRITE_KEY', {
  apiHost: 'us-east-1.hightouch-events.com',
  user: {
    sessions: {
      autoTrack:true,
      // Set the timeout to 60 minutes.
      timeout: 60*60*1000,
    }
  }
})

Campaign Attribution (UTM)

Hightouch automatically captures UTM parameters that you pass in URLs. You can also manually pass UTMs into the context.campaign field.

UTM parameters are only used when linking to your site from outside of your domain. When a visitor arrives to your site using a link containing UTM parameters, Hightouch's Browser SDK will automatically parse the URL query string and store UTM parameters within the context.campaign object as outlined here. These parameters do not persist to subsequent calls unless you pass them explicitly.

UTM parameters:

If you’d like UTM parameters to persist in subsequent calls, you’ll need to manually set those fields in context.campaign. For example:

htevents.page("My Page", {}, {
  campaign: {
    name: "TPS Innovation Newsletter",
    source: "Newsletter",
    medium: "email",
    term: "tps reports",
    content: "image link"
  },
});

Cookies and LocalStorage

Hightouch stores cookies to track information about website visitors across multiple visits.

• htjs_user_id: ID tracking known or identified users as defined here.
• htjs_anonymous_id: ID tracking anonymous website visitors as defined here.
• htjs_group_id: ID tracking the group a user is associated with as defined here.
• htjs_sesh: Information about the user's current session as defined here.

In addition to tracking this information in cookies, we use localStorage to track this as well. In localStorage, we also track:

• htjs_user_traits: Traits defined about the user being tracked
• htjs_group_properties: Properties defined about the group being tracked

For more information on measures to increase persistence of cookies, please refer to our guide on proxying and server-side cookies.