When to use methods

  • To react on some event happening in the DOM
  • To call a function when something happens in your component. You can call a methods from computed properties or watchers.

When to use computed properties

  • You need to compose new data from existing data sources
  • You have a variable you use in your template that’s built from one or more data properties
  • You want to reduce a complicated, nested property name to a more readable and easy to use one, yet update it when the original property changes
  • You need to reference a value from the template. In this case, creating a computed property is the best thing because it’s cached.
  • You need to listen to changes of more than one data property

When to use watchers

  • You want to listen when a data property changes, and perform some action
  • You want to listen to a prop value change
  • You only need to listen to one specific property (you can’t watch multiple properties at the same time)
  • You want to watch a data property until it reaches some specific value and then do something