Google Analytics pushing worng value in 'checkout' actionField option - google-analytics

Question

There is common JSPF var dataLayer = window.dataLayer = dataLayer || []; has declared.
On Checkout step -3
dataLayer.push({
'event' : 'checkout',
'ecommerce' : {
'currencyCode' : 'GBP',
'checkout' : {
'actionField' : {
'step' : 3,
'option' : '<some-value>',
'tax' : '<some-value>',
**'action' : 'checkout'**
},
'products' : '<some-value>'
}
}
});
It is working fine. Pushing correct data.
On Checkout step - 4
dataLayer.push({
'event' : 'checkout',
'ecommerce' : {
'currencyCode' : 'GBP',
'checkout' : {
'actionField' : {
'step' : 4,
'option' : '<some-value>',
'tax' : '<some-value>',
**'action' : 'purchase'**
},
'products' : '<some-value>'
}
}
});
It still pushing 'checkout' not 'purchase'. The datalayer pushing of elements from same file for step-3 and step-4. And declaration is from .JSPf which is included in it. It seems like 'action' element is cached.I had tried with cleaning browser history but no success.
Please tell where i had lacked.

Answer 1

The actionField.action field is automatically populated by GTM/Universal Analytics. You should never manually add a value to it.
The field value is derived from the property name that wraps actionField and products. Thus if the hit is a "Checkout" hit, the property key would be checkout, and if the hit is a "Purchase" hit, the property key would be purchase.
Example Checkout hit for step 4:
event: 'checkout',
ecommerce: {
checkout: {
actionField: {
step: 4,
option: 'some-option'
}
}
}
Example Purchase hit:
event: 'purchase',
ecommerce: {
currencyCode: 'GBP',
purchase: {
actionField: {
id: 'some-transaction-id',
revenue: 'some-transaction-revenue',
tax: 'some-transaction-tax',
shipping: 'some-transaction-shipping'
},
products: [{
...products in the purchase...
}]
}
}