# Store

There are a number of different options for writing and accessing the store in a Nuxt project using TypeScript.

# Class-based

# vuex-module-decorators

One of the most popular approaches is vuex-module-decorators - see guide.

WARNING

There is currently a very serious security issue with nuxt-module-decorators: there is cross-request state pollution - so you will need to make sure that there is no request-specific information in the SSR store. See this PR for the current status of the fix.

For use with Nuxt, there are few key provisos:

  1. Your modules must be decorated with stateFactory: true, so for example:

    ~/store/mymodule.ts:

    import { Module, VuexModule, Mutation } from 'vuex-module-decorators'
    
    @Module({
      name: 'mymodule',
      stateFactory: true,
      namespaced: true,
    })
    class MyModule extends VuexModule {
      wheels = 2
    
      @Mutation
      incrWheels(extra) {
        this.wheels += extra
      }
    
      get axles() {
        return this.wheels / 2
      }
    }
    
  2. If you want to access the store without initialising it in each component, you can do so using an initialiser plugin, for example: ~/store/index.ts:

    import { Store } from 'vuex'
    import { initialiseStores } from '~/utils/store-accessor'
    
    const initializer = (store: Store<any>) => initialiseStores(store)
    
    export const plugins = [initializer]
    export * from '~/utils/store-accessor'
    
  3. If you want to access the Nuxt app instance, you will need to do something similar with a plugin, for example: ~/plugins/axios-accessor.ts:

    import { Plugin } from '@nuxt/types'
    import { initializeAxios } from '~/utils/api'
    
    const accessor: Plugin = ({ $axios }) => {
      initializeAxios($axios)
    }
    
    export default accessor
    

    ~/utils/api.ts:

    import { NuxtAxiosInstance } from '@nuxtjs/axios'
    
    let $axios: NuxtAxiosInstance
    
    export function initializeAxios(axiosInstance: NuxtAxiosInstance) {
      $axios = axiosInstance
    }
    
    export { $axios }
    

    ~/store/users.ts:

    import { Module, VuexModule, Action, Mutation } from 'vuex-module-decorators'
    import { $axios } from '~/utils/api'
    import { User } from '~/types'
    
    @Module({
      name: 'users',
      stateFactory: true,
      namespaced: true,
    })
    class UserModule extends VuexModule {
      users: User[] = []
    
      @Mutation
      setUsers(users: User[]) {
        this.users = users
      }
    
      @Action
      async getUsers() {
        const users = $axios.$get('/users')
        this.setUsers(users)
      }
    }
    

# vuex-class-component

vuex-class-component is a very promising class-based approach to the Nuxt store, and the syntax is very similar to vuex-module-decorators. It has just released a new API, although it is not yet compatible in its entirety with Nuxt. The workaround is to define modules with a decorator:

@Module({ namespacedPath: 'foo' })
export default class extends VuexModule {}

See this issue for the current status of the compatibility issue with Nuxt.

# Vanilla

# Basic typing

Vuex supplies very basic types for use with the store. You can use these to help define your store. For example:

~/store/index.ts:

import { GetterTree, ActionTree, MutationTree } from 'vuex'

export const state = () => ({
  things: [] as string[],
  name: 'Me',
})

export type RootState = ReturnType<typeof state>

export const getters: GetterTree<RootState, RootState> = {
  name: state => state.name,
}

export const mutations: MutationTree<RootState> = {
  CHANGE_NAME: (state, newName: string) => (state.name = newName),
}

export const actions: ActionTree<RootState, RootState> = {
  fetchThings({ commit }) {
    const things = this.$axios.$get('/things')
    console.log(things)
    commit('CHANGE_NAME', 'New name')
  },
}

# Accessing the store

# nuxt-typed-vuex

Vuex does not provide useful types for accessing the store from your app. this.$store remains untyped in a Nuxt app.

There is a new project, nuxt-typed-vuex - and guide - which aims to remedy that - providing a strongly-typed accessor for a vanilla Nuxt store.

# Bring your own

Alternatively, you can provide your own types at the point of use.

~/components/MyComponent.vue:

<script lang="ts">

import { Component, Vue } from 'nuxt-property-decorator'
import { RootState } from '~/store'

@Component
export default class MyComponent extends Vue {
    get myThings() {
        return (this.$store.state as RootState).things
    }
}