Event tracking

Event tracking can be achieved in different ways, following Google specifications

passing parameters in this exact order

this.$ga.event('category', 'action', 'label', 123)

an object literal is also possible

this.$ga.event({
  eventCategory: 'category',
  eventAction: 'action',
  eventLabel: 'label',
  eventValue: 123
})

Google Analytics docs: event tracking