message: docs: code example on 'Fetching Before Navigation' with a better context
diff: @@ -83,6 +83,7 @@ export default {
  },
  beforeRouteEnter(to, from, next) {
  getPost(to.params.id, (err, post) => {
  + // `setData` is a method defined below
  next(vm => vm.setData(err, post))
  })
  },
  @@ -96,6 +97,15 @@ export default {
  this.error = error.toString()
  }
  },
  + methods: {
  + setData(error, post) {
  + if (error) {
  + this.error = error
  + } else {
  + this.post = post
  + }
  + }
  + }
  }
  ```
  