Can I call commit from one of mutations in Vuex store

Question

I have a vuex store, like following:

import spreeApi from '../../gateways/spree-api'
// initial state
const state = {
  products: [],
  categories: []
}

// mutations
const mutations = {
 SET_PRODUCTS: (state, response) => {
   state.products = response.data.products
   commit('SET_CATEGORIES')
 },
 SET_CATEGORIES: (state) => {
   state.categories = state.products.map(function(product) { return product.category})
 }

}

const actions = {
 FETCH_PRODUCTS: (state, filters) => {
   return spreeApi.get('products').then(response => state.commit('SET_PRODUCTS', response))
 }
}

export default {
  state,
  mutations,
  actions
}

I want to call mutation: SET_CATEGORIES from mutation: SET_PRODUCTS, But this gives me error:

projectFilter.js:22 Uncaught (in promise) ReferenceError: commit is not defined(…)

What should be correct way to do this. I tried store.commit and this.commit, but these also gave similar errors.

Answer 1

When you are already doing a mutation, there is no way to commit another mutation. A mutation is a synchronous call which changes the state. Within one mutation, you will not be able to commit another mutation.

Here is the API reference for Vuex: https://vuex.vuejs.org/en/api.html

As you can see, a mutation handler receives only state and payload, nothing more. Therefore you are getting commit as undefined.

In your case above, you can set the PRODUCT and CATEGORIES as part of the same mutation handler as a single commit. You can try if the following code works:

// mutations
const mutations = {
    SET_PRODUCTS_AND_CATEGORIES: (state, response) => {
        state.products = response.data.products
        state.categories = state.products.map(function(product) { return product.category})
    },
    // ...
}

EDIT: Please refer to the answer below, provided by Daniel S. Deboer. The correct method is to commit two mutations from a single action, as described in his answer.