Why is $store not defined?

Question

I am struggling to developed a project with vuejs and vuex, but it does not work with this.$store.state.count in the component. Why?

My config:

"vuex": "^2.0.0"

store.js:

import Vue from 'vue'
import Vuex from 'vuex'
Vue.use(Vuex)

export default new Vuex.Store({
  state: {
    count: 12
  },
  mutations: {
    increment (state) {
      state.count++
    }
  },
  strict: true
})

main.js:

import store from './vuex/store'
import Vue from 'vue'

new Vue({
  store,
  .
  .
  .
}).$mount('#app')

component.js:

<script>
export default {
    name: 'landing-page',
    created: () => {
      console.log('status2')
      console.log(this.$store.state.count)
    }
  }
</script>

Error:

Uncaught TypeError: Cannot read property '$store' of undefined

Solution 1

You will never, ever edit the store directly.

You will ALWAYS trigger mutations.

As so (component.js):

<script>
import store from './vuex/store'

export default {
  name: 'landing-page',
  computed: {
    counter () {
      return store.state.count // get state
    }
  },
  created: () => {
    store.commit('increment') // set state
  }
}
</script>

Solution 2

That is because this in arrow function is not what you expect as this in "normal function". You can refer to Arrow functions or Javascript ES6 — Arrow Functions and Lexical this for more information

Comments

[Sebastian Simon]

The error does not mean that $store is not defined. Read carefully. It says that this is not defined.

[steve]

Thanks. But I just want to get state, not set.

[joaumg]

Edited, to reflect the get part (;

[Dave Stein]

I don't understand this example as a Vue noob. Examples show me instantiating a store, and passing to Vue. When you import store in this example, are you importing an instantiated Vuex object then? Why wouldn't it be passed down in some way from Vue?

[joaumg]

@DaveStein "When you import store in this example, are you importing an instantiated Vuex object then?", Yes. You can also pass it in the Vue as mentioned here: vuex.vuejs.org/en/… to avoid relying on the global singleton...