google-analytics - Add Custom Variables To Google Universal Analytics Reports Using Google Tag Manager

Question

I am currently trying to add custom variables to my analytics report to see if there is any pattern with the ratio of customers that add to cart and the number of product images or delivery message on a product page.

I am currently trying to push these variables to the data layer using macros in GTM. I can see the data appearing in the macro but it doesn't seem to be appearing in the custom report that I have setup.

Can someone explain the best way of pushing custom variables into the data layer and then getting that data to appear in GUA reports?

I am currently trying to push to the data layer using the example below via product details impression:

'ecommerce': {
    'detail': {
      'products': [{
        'name': 'Triblend Android T-Shirt',
        'id': '12345',
        'price': '15.25',
        'brand': 'Google',
        'category': 'Apparel',
        'variant': 'Gray'
        'dimension1' : 5
       }]
     }
   }
});

Answer 1

I worked out how to resolve the issue. I was firing the tag in GTM before the DOM was ready so therefore none of the variables were being set when the tag fired. I simply added {{event}} equals gtm.dom to the firing rule for the tag and it started working.