$store properties are not reactive when using computed property (Vuex)

Question

Your code should work if you setup everything correctly: http://codepen.io/CodinCat/pen/RKZeZe?editors=1010

A very common mistake is that you didn’t give your state initial data.

You should declare the state shape explicitly, so instead of

state: {}

// or

state: {
  nav: {}
}

do this:

state: {
  nav: {
    type: '...'
  },
  ...
}

or the properties will not be reactive, like this example: http://codepen.io/CodinCat/pen/ggxBEV?editors=1010

And make sure you did update the state, maybe the problem is just you didn’t update the state correctly as you expected.