We use [Snowplow](https://github.com/snowplow/snowplow) for tracking custom events (available in GitLab [Enterprise Edition](https://about.gitlab.com/pricing/) only).
In addition to Snowplow's built-in method for tracking page views, we use a generic tracking function which enables us to selectively apply listeners to events.
The generic tracking function can be imported in EE-specific JS files as follows:
```javascript
import { trackEvent } from `ee/stats`;
```
This gives the user access to the `trackEvent` method, which takes the following parameters:
| `category` | string | Describes the page that you're capturing click events on. Unless infeasible, please use the Rails page attribute `document.body.dataset.page` by default. | true |
| `eventName` | string | Describes the action the user is taking. The first word should always describe the action. For example, clicks should be `click` and activations should be `activate`. Use underscores to describe what was acted on. For example, activating a form field would be `activate_form_input`. Clicking on a dropdown is `click_dropdown`. | true |
| `additionalData` | object | Additional data such as `label`, `property`, and `value` as described [in our Feature Instrumentation taxonomy](https://about.gitlab.com/handbook/product/feature-instrumentation/#taxonomy). | false |
Read more about instrumentation and the taxonomy in the [Product Handbook](https://about.gitlab.com/handbook/product/feature-instrumentation).
### Tracking in `.js` and `.vue` files
The most simple use case is to add tracking programmatically to an event of interest in Javascript.
The following example demonstrates how to track a click on a button in Javascript by calling the `trackEvent` method explicitly:
Sometimes we want to track clicks for multiple elements on a page. Creating event handlers for all elements could soon turn into a tedious task.
There's a more convenient solution to this problem. When working with HAML templates, we can add `data-track-*` attributes to elements of interest. This way, all elements that have both `data-track-label` and `data-track-event` attributes assigned get marked for event tracking. All we have to do is call the `bindTrackableContainer` method on a container which allows for better scoping.
Below is an example of `data-track-*` attributes assigned to a button in HAML:
By calling `bindTrackableContainer('.my-container')`, click handlers get bound to all elements located in `.my-container` provided that they have the necessary `data-track-*` attributes assigned to them.
| `data-track-label` | The `label` in `trackEvent` | true |
| `data-track-event` | The `eventName` in `trackEvent` | true |
| `data-track-property` | The `property` in `trackEvent`. If omitted, an empty string will be used as a default value. | false |
| `data-track-value` | The `value` in `trackEvent`. If omitted, this will be `target.value` or empty string. For checkboxes, the default value being tracked will be the element's checked attribute if `data-track-value` is omitted. | false |
Since Snowplow is an Enterprise Edition feature, it's necessary to create a CE backport when adding `data-track-*` attributes to HAML templates in most cases.
