The data layer contains built-in variables that collect basic information about the page being tracked. These variables include cookies, standard DOM variables from the page, and Tealium-specific variables about the loaded configuration.

Learn more about the types of data layer variables available.

Standard Page Data

The following variables are generated from the standard JavaScript properties available for the web page.

The example values shown are based on the following page URL:

http://www.example.com/path/file.html?param1=value1#hash=fragment

Cookies

The following variables are stored and maintained in a single cookie named TEAL. Each is a variable in the TEAL object.

The following is an example of the document.cookie format of the TEAL cookie, which shows the variable values separated by $ characters.

TEAL=v:927b2ebc092a70110329356772472215264145f9fa1$t:1628543914615$s:1628542077230%3Bexp-sess$sn:1$en:3

Tealium Data

Example Data

The following is an example of the built-in data layer that is automatically available.

{
        "cp._ga": "GA1.2.1370368844.1628542067",
        "cp._gid": "GA1.2.73283117.1628542067",
        "tealium_session_number": 1,
        "tealium_session_event_number": 3,
        "tealium_session_id": "1628542077230",
        "tealium_visitor_id": "927b2ebc092a70110329356772472215264145f9fa1",
        "dom.referrer": "",
        "dom.title": "Example dot com",
        "dom.domain": "example.com",
        "dom.query_string": "",
        "dom.hash": "",
        "dom.url": "https://example.com/",
        "dom.pathname": "/",
        "dom.viewport_height": 936,
        "dom.viewport_width": 1517,
        "meta.description": "View",
        "meta.viewport": "width=device-width, initial-scale=1",
        "meta.theme-color": "#13B0E9",
        "tealium_cookie_domain": "example.com",
        "tealium_domain": "example.com",
        "tealium_event": "test event",
        "tealium_account": "xxxxxxxxxxxx",
        "tealium_profile": "main",
        "tealium_environment": "prod",
        "tealium_datasource": "test1234",
        "tealium_random": "9870188345895229",
        "tealium_library_name": "tealium.js",
        "tealium_library_version": "5.0.3",
        "tealium_timestamp_epoch": 1628542114,
        "tealium_timestamp_utc": "2021-08-09T20:48:34.616Z",
        "tealium_timestamp_local": "2021-08-09T13:48:34.616",
        "timing.domain": "example.com",
        "timing.pathname": "/",
        "timing.query_string": "",
        "timing.timestamp": 1628542085435,
        "timing.dns": 1,
        "timing.connect": 99,
        "timing.response": 0,
        "timing.dom_loading_to_interactive": 7,
        "timing.dom_interactive_to_complete": 129,
        "timing.load": 0,
        "timing.time_to_first_byte": 95,
        "timing.front_end": 163,
        "timing.fetch_to_response": 210,
        "timing.fetch_to_complete": 373,
        "timing.fetch_to_interactive": 244
}

How Data Layer Variables are Flattened

Google Tag Manager events are flattened to Tealium attribute names in order to meet the Tealium Customer Data Hub specifications. The event data is received by Tealium EventStream.

The value of tealium_event is the value of the event in the dataLayer.push call. Google Tag Manager sets the default page view value to gtm.js as the name of the event. To override the default, set the Tealium Event config setting to a variable that contains the event name.

Attributes are not automatically added. You must add these attributes in Tealium EventStream.

E-Commerce

The following purchase event example shows how the client-side e-commerce events get flattened.

dataLayer.push({
  'ecommerce': {
    'purchase': {
      'actionField': {
        'id': 'T12345',    // Transaction ID. Required for purchases and refunds.
        'affiliation': 'Online Store',
        'revenue': '35.43',
        'tax':'4.90',
        'shipping': '5.99',
        'coupon': 'SUMMER_SALE'
      },
      'products': [{
        'name': 'Triblend Android T-Shirt',     // Name or ID is required.
        'id': '12345',
        'price': '15.25',
        'brand': 'Google',
        'category': 'Apparel',
        'variant': 'Gray',
        'quantity': 1,
        'coupon': ''
       },
       {
        'name': 'Donut Friday Scented T-Shirt',
        'id': '67890',
        'price': '33.75',
        'brand': 'Google',
        'category': 'Apparel',
        'variant': 'Black',
        'quantity': 1
       }]
    }
  }
});

After flattening, the purchase event becomes:

"ecommerce.purchase.actionField.affiliation": "Online Store"
"ecommerce.purchase.actionField.coupon": "SUMMER_SALE"
"ecommerce.purchase.actionField.id": "T12345"
"ecommerce.purchase.actionField.revenue": "35.43"
"ecommerce.purchase.actionField.shipping": "5.99"
"ecommerce.purchase.actionField.tax": "4.90"
"ecommerce.purchase.products.brand": [ "Google", "Google" ]
"ecommerce.purchase.products.category": [ "Apparel", "Apparel" ]
"ecommerce.purchase.products.coupon": [ "", "" ]
"ecommerce.purchase.products.id": [ "12345", "67890" ]
"ecommerce.purchase.products.name": [ "Triblend Android T-Shirt", "Donut Friday Scented T-Shirt" ]
"ecommerce.purchase.products.price": [ "15.25", "33.75" ]
"ecommerce.purchase.products.variant": [ "Gray", "Black" ]
"ecommerce.purchase.products.quantity": [ "1", "1" ]

The flattener uses dot notation to create the key, and the value is set to an array of all values from the purchase event.

Events

The following dataLayer.push command fires when “event” is included in the data layer:

window.dataLayer.push({
  event: "test_number",
  type_number: 5,
  type_string: 'hello',
  type_object: { someKey: 'someValue' },
  type_array: [1,2,3,4],
  type_function: function() { return 'hello'; },
  type_boolean: true
});

The data layer that arrives in Tealium EventStream looks as follows. Only the type_object is flattened and the function is removed.

{
    "event": "test_number",
    "type_number": 5,
    "type_string": "hello",
    "type_object.someKey": "someValue",
    "type_array": [1, 2, 3, 4],
    "type_boolean": true
}