data layer - measurecamp vii 2015

@SimoAhava

The Data Layer MeasureCamp @SimoAhava

Typically, there are three definitions

of Data Layer that we use in the digital world. @SimoAhava from @ReaktorNow at #MeasureCamp

1. Set of business requirementsfor tracking digital assets,visits, and visitors.

2. Encoded, global data structure, accessed and modified by connected platforms.

2. Data model of a connected platform, which copies or digests information in the global structure.

dataLayer.push({ 'pageType' : 'home' });

google_tag_manager['GTM-123'] .dataLayer .set('pageType', 'home');

@SimoAhava from @ReaktorNow at #MeasureCamp

Across all three definitions, the purpose of a Data Layer

is simple:



DMP / DWH / TMS / etc.

X X

Actions Presentation

Data Layer


DMP / DWH / TMS / etc.

X X

Actions Presentation

Data Layer

The purpose of a Data Layer is to provide a bilateral layer on the digital asset, which decouples, normalises, and uniformly encodes semantic

information passed through and stored within.

As a set of business requirements, the Data

Layer is a living document.


- Can be encoded into a spreadsheet, a text document, or even simply as an interface design of the front-end

- Important thing is to identify the variables in the Data Layer, with context and ownership explicitly stated — each variable needs to have business impact / tie-in

- It’s a living document, so it should be kept up-to-date when changes to the dataLayer are implemented

- Usually the document only reflects variables that are produced server-side (upon page render)


As a global data structure, the Data Layer is a

repository of information.


GTM’s dataLayer is an Array-type structure, which has a proprietary .push() method


Interaction is done most commonly by pushing an {object literal}, which has keys and values of any JavaScript type.


The only method that works with GTM is push. No other Array methods have an impact.


As an internal data model, the platform utilizes data in

the global dataLayer.


When you push a key into dataLayer, it gets copied into the internal data model.


When the value is an object, a recursive merge takes place.


The data model has some special methods as well.


Key learnings about how the Data Layer should could

be used:


Pre-container-snippet-dataLayer is available to Tags firing with "All Pages" or "Page View" Triggers.


Still, it’s a good idea to always have the 'event' key in the push, so that you can always use a Custom Event Trigger as well.


Never use var dataLayer = []; as you can unwittingly destroy your GTM implementation.


eventCallback can be used to execute a function after the event has completed (i.e. all dependent Tags have fired).


Values in the data model can be accessed with the Data Layer Variable.


Version 2: - Dots can be used to access nested key names, and/or JavaScript properties: —— someKey.nestedKey —— someKey.parentElement.href - Understands recursive merge, i.e. returns the full, merged object

Version 1: - Dots have no function, i.e. they are interpreted as being part of the key name - Does not understand recursive merge, so only returns the value that was most recently pushed into this key


Square bracket notation does not work, replace with special dot notation to access Array members (Version 2 only).


Values in the data model persist for the duration of the event. You can’t update values during an event with dataLayer.push().


The Data Layer: http://goo.gl/9r4Ndw

Google Tag Manager’s Data Model: http://goo.gl/WhvSI9


FURTHER READING

@SimoAhava @ReaktorNow

THANK YOU

data layer - measurecamp vii 2015

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