How do you combine local computed properties with mapState helper? 152

 How do you combine local computed properties with map State helper?

You can easily combine local computed properties with the map State helper in Vuex. Here's how:

1. Using object spread operator:

This is the most concise and modern approach. Import mapState and spread its mapped properties along with local computed properties in a single computed object:

JavaScript

import { mapState } from 'vuex'

export default {
  computed: {
    ...mapState(['someStateValue']),
    localComputed1() {
      // Local logic using state or other computed properties
      return somethingBasedOnData;
    },
    localComputed2(state, getters) {
      // Access state and getters directly (optional)
      return anotherCalculation;
    },
  },
}

2. Manually merging objects:

You can individually define mapState and local computed properties, then merge them into a single computed object:

JavaScript

import { mapState } from 'vuex'

export default {
  computed: {
    ...mapState(['someStateValue']),
    localComputed1() {
      // Local logic based on state or other computed properties
      return somethingBasedOnData;
    },
  },
  computed: { // Another computed property section
    localComputed2(state, getters) {
      // Access state and getters directly (optional)
      return anotherCalculation;
    },
  },
}

3. Nested computed properties:

If you need more organization, you can define a dedicated computed property for your local calculations, then access it within another computed property mapped by mapState:

JavaScript

import { mapState } from 'vuex'

export default {
  computed: {
    localCalculations() {
      // Local logic based on state or other computed properties
      return somethingBasedOnData;
    },
    ...mapState({
      combinedProperty: state => state.someStateValue + this.localCalculations,
    }),
  },
}

Remember that mapState returns an object, so when using object spread or merge, ensure these are defined within a computed property section. Each approach has its advantages, so choose the one that best suits your code structure and preferences.

I hope this clarifies how to combine local computed properties with mapState! Feel free to ask if you have further questions.