Gravity Form by google tagmanager

custom html -  cJS - Gravity form - listhner
===
<script>
jQuery(document).ready( function() {
jQuery(document).bind('strattic-form-success', function(e){
  var formId = e.detail.form.id
  var formDetails = e.detail.formattedData
	window.dataLayer.push({
          'event' : 'gravityFormSubmission',
          'gfformID' : formId,
          'gfformSubmission' : formDetails
	});
});
	})
</script>
===
Variable: 
dlv - form id -      gfformID


1. using Custom javascript variable by input box name
-----------------
function() {
    return document.getElementsByName('input_box_name')[0] ? document.getElementsByName('input_box_name')[0].value: '';
}

-----!important---
confermation page script

<script>
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
	'event': 'gravity_form_submit',
	'firstName': '',
	'lastName': '',
	'email': '',
	'phone':''
});
</script>

=====
#How To Track Gravity Form Submission With Google Tag Manager
If you are using the Gravity form on your website and you want to measure the form conversions in your analytics tools and advertising platform

You will have to use the Gravity form event listener and Google Tag Manager to make this possible.

First, create a custom HTML tag type, paste the event listener code there and fire it on pageview or DOM ready.

Next, you’ll set up a custom event trigger with the event name [formSubmissionSuccess] used to fire your marketing pixels/tags on successful Gravity form submissions.

To capture the Gravity form ID, create a dataLayer variable with the key [formID].  you can push the form ID into your analytics as an event parameter.