Amplitude JavaScript SDK wrapper V2 for Google Tag Manager

The purpose of this wrapper is to provide a JavaScript interface for interacting with the window.amplitude client.

The wrapper has been designed with Google Tag Manager in mind. GTM's custom templates offer a way to deploy custom JavaScript without having to resort to Custom HTML tags, and with the ability to craft a user interface for the scripts within Google Tag Manager.

However, one of the defining features of custom templates is their sandboxed JavaScript API inventory, which severely restricts what type of browser JavaScript can be executed in the template code.

Amplitude's Browser SDK makes use of JavaScript features which are not permitted by the sandbox of GTM's custom templates (e.g. object instances initiated with the new keyword, this and prototype, custom parameters on the <script> element, etc.).

Thus, in order to interact with Amplitude's JavaScript SDK via Google Tag Manager's custom templates (or any other context where the aforementioned JavaScript features cannot be used), this wrapper is required.

Breaking changes in V2

This wrapper abandonds the legacy SDK and instead loads the Marketing Analytics Browser SDK.

In addition to the changes in the general usage of the SDK, there are some breaking changes in this wrapper itself.

Instance names are no longer used

It is no longer possible to create unique instances of the amplitude tracking interface.

Commands need to provided as-is, without the instance prefix.

V1:

window._amplitude(
  'myInstance.setOptOut',
  true
);

V2:

window._amplitude(
  'setOptOut',
  true
);

Deprecated event names

The following event names have been either completely removed or they have a new name in this wrapper.

| Event in V1 | Event in V2 | |-|-| | isNewSession | N/A | | setUserProperties | identify | | clearUserProperties | identify | | regenerateDeviceId | reset | | setVersionName | N/A | | logEvent | track | | logEventWithTimestamp | track | | logEventWithGroups | track |

Change to productId in the revenue call

The syntax of the revenue wrapper call has changed slightly, and the product ID is now passed with the productId key rather than id.

V1:

window._amplitude(
  'revenue',
  {
    id: 'product_id',
    ...
  }
);

V2:

window._amplitude(
  'revenue',
  {
    productId: 'product_id',
    ...
  }
);

How it works

When the wrapper JavaScript is loaded in the browser, the global method window._amplitude() is created for interacting with the wrapper.

This namespace includes the following methods. Each method can be invoked by passing the command name as the first argument of the call to window._amplitude().

For example, to initialize a tracker with an API key, a user ID, and some custom options, you can use this wrapper command:

window._amplitude(
  'init', // Run the init command
  'abcd1234', // The API key
  'user123', // (optional) User ID
  {trackingOptions: {ipAddress: false}, appVersion: '2.0.1'} // (optional) Additional options
);

init

Link to specification

Use this command to initialize a tracker instance.

See this specification for what you can pass in the configOptions object.

Example:

// Initialize a new Amplitude tracker with API key "abcd1234"
window._amplitude(
  'init',
  'abcd1234',
  null,
  configOptions
);

track

Link to specification

Use this command to track an event.

Example:

// Track an event named 'custom_scroll' with some event properties, options, and a group
window._amplitude(
  'track',
  'custom_scroll',
  {
    scroll_depth: 90  // Event property
  },
  {
    time: Date.now() - 50000, // Set event timestamp to 50 seconds in the past
    plan: 'enterprise' // Set event-level group type to "plan" and group name to "enterprise"
  }
);

identify

Link to specification

Run user property operations for the current user. The 'identify' method utilizes a single parameter, which is an array of individual user property operations. Each operation is its own array, following this format:

// Wrapper array
[
  // First command
  ['identifyCommand', 'userProperty', 'value'],
  // Second command
  ['identifyCommand', 'userProperty', 'value'],
  // etc.
  [...]
]

The identify API processes the commands in the order they are in the argument array.

Supported identifyCommand values are: add, append, prepend, set, setOnce, unset, preInsert, postInsert, clearAll. The last one takes no parameters and can be used to remove all user properties from the user.

Example:

window._amplitude(
  'identify',
  [
    ['set', 'user_status', 'customer'],
    ['add', 'purchases', 1],
    ['append', 'purchased_products', 'product_123']
  ]
);

Example with clearAll:

window._amplitude(
  'identify',
  [
    ['clearAll']
  ]
);

setGroup

Link to specification

Add user to a group or groups.

Example:

// Adds the user to groups "org_1" and "org_2" in orgId.
window._amplitude(
  'setGroup',
  'orgId',
  ['org_1', 'org_2']
);

groupIdentify

Link to specification

Set or update properties of particular groups.

The method takes three parameters: a group type, a group name, and an array of property operations (see identify above).

Example:

// Sets the property "plan" to "enterprise" for the given group.
window._amplitude(
  'groupIdentify',
  'myOrganization', // Group type
  'myGroup', // Group name
  [
    ['set', 'plan', 'enterprise']
  ]
);

revenue

Link to specification

Log a Revenue event with details about the product. The product details are passed as an object with productId and price being required keys, and quantity, revenueType, and eventProperties as optional.

Example:

window._amplitude(
  'revenue',
  {
    productId: 'cool_t_shirt', // required
    price: 10.88, // required
    quantity: 1,
    revenueType: 'purchase',
    eventProperties: {'coupon_used': true}
  }
);

flush

Link to specification

Trigger the client to send the buffered events immediately.

Example:

window._amplitude('flush');

getUserId

Returns the current user ID.

Example:

window._amplitude('getUserId');

setUserId

Link to specification

Set the current user ID. The user ID should be a string or null. Use the latter to reset the User ID.

Example:

window._amplitude(
  'setUserId',
  'user_12345'
);

getSessionId

Returns the current session ID.

Example:

window._amplitude('getSessionId');

setSessionId

Link to specification

Set a new session ID. Format must be in milliseconds since epoch (UNIX time).

Example:

window._amplitude(
  'setSessionId',
  1634547544137
);

getDeviceId

Returns the current device ID.

Example:

window._amplitude('getDeviceId');

setDeviceId

Link to specification

Manually override the user's device ID. Must not have the "." character. Recommended format is UUID.

Example:

window._amplitude(
  'setDeviceId',
  'abcd1234-defg-hij1-klm2-yt4t112dabdd'
);

reset

Link to specification

Anonymize the user by setting the userId to undefined and setting the deviceId to a new UUID value.

Example:

window._amplitude('reset');

setOptOut

Link to specification

Opt current user out of tracking.

Example:

window._amplitude(
  'setOptOut',
  true // Set to true to opt user out of tracking
);

setTransport

Set the transport type to one of xhr, sendBeacon, or fetch.

Example:

window._amplitude(
  'setTransportType',
  'sendBeacon'
);