[Vuejs]-Trying to understand "undefined" warning in Vue.js

As discussed in the comments to your post, it’s due to the async API call yo do in created() to get the permissions object initially.

I suggest you use something like https://github.com/vuejs/vue-async-data. It allows you to get data asynchronously (e.g. with vue-resource) and gives you a way to hide components content until loading the data has finished.

Though you can easily simulate this on your own:

data: function () {
  return { loaded: false, permissions: {} }
},
created() {
  return this.$http(...).then(function (result) {
    this.permissions = result.data.permissions // or however your data is
    this.loaded = true
  })
}

and in the template, use v-if="loaded" on a wrapping div to hide the content until permissions are actually loaded.