CODEWITHSUNDEEP
vuejs2vuex
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Reputation: 2139

How do I call a getter from another getter in Vuex?

Consider a simple Vue blog:
I'm using Vuex as my datastore and I need to set up two getters: a getPost getter for retrieving a post by ID, as well as a listFeaturedPosts that returns the first few characters of each featured post. The datastore schema for the featured posts list references the posts by their IDs. These IDs need to be resolved to actual posts for the purposes of showing the excerpts.

store/state.js

export const state = {
  featuredPosts: [2, 0],
  posts: [
    'Lorem et ipsum dolor sit amet',
    'Lorem et ipsum dolor sit amet',
    'Lorem et ipsum dolor sit amet',
    'Lorem et ipsum dolor sit amet',
    'Lorem et ipsum dolor sit amet',
  ]
}

store/getters.js

export default getPost = (state) => (postID) => {
  return state.posts[postID]
}

export default listFeaturedPosts = (state, getters) => () => {
  console.log(getters) // {}

  return state.featuredPosts.map(postID => getters.getPost(postID).substring(0, EXCERPT_LENGTH);
}

store/index.js

import Vue from 'vue'
import Vuex from 'vuex'
import state from './state'
import * as getters from './getters'
import * as mutations from './mutations'

Vue.use(Vuex)

export default new Vuex.Store({
  state,
  getters,
  mutations
})

According to the documentation, the getters parameter can be used to access other getters. However, when I try to access getters from inside listFeaturedPosts, it's empty, and I get an error in the console due to getters.getPost being undefined in that context.

How do I call getPost as a Vuex getter from inside listFeaturedPosts in the example above?

Upvotes: 181

Views: 83841

Answers (5)

Jose Seie
Jose Seie

Reputation: 890

I Tested without state and didn't work. That's why state is necessary.

this works:

export default foo = (state, getters) => {
    return getters.yourGetter
}

this didn't work

export default foo = (getters) => {
    return getters.yourGetter
}

Upvotes: 22

whusterj
whusterj

Reputation: 3419

In VueJS 2.0, you must pass both state and getters.

Getters are passed to other getters as the 2nd Argument:

export default foo = (state, getters) => {
    return getters.yourGetter
}

Official documentation: https://vuex.vuejs.org/guide/getters.html#property-style-access

Upvotes: 297

OziOcb
OziOcb

Reputation: 407

Getters receive other getters as the 2nd argument

getters: {
  doneTodos: state => {
    return state.todos.filter(todo => todo.done)
  },
  doneTodosCount: (state, getters) => {
    return getters.doneTodos.length
  }
}

Here is a link to the official docs - https://vuex.vuejs.org/guide/getters.html#property-style-access

Upvotes: 29

Be Kind
Be Kind

Reputation: 5172

Pass getters as the second argument to access local and non-namespaced getters. For namespaced modules, you should use rootGetters (as the 4th argument, in order to access getters defined within another module):

export default foo = (state, getters, rootState, rootGetters) => {
    return getters.yourGetter === rootGetters['moduleName/getterName']
}

Upvotes: 41

Angie
Angie

Reputation: 140

instead of passing state, pass getters and then call any other getter you want. Hope it helps.

In your store/getters.js

export default foo = (getters) => {
   return  getters.anyGetterYouWant
}

Upvotes: -6

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