VueJS 3 / Vuex - How to display data from a nested json result

Question

Dears,

I've been struggling with this for hours, even following basics tutorials.

I'm trying to display some data in Json in my Vue 3 project, when a data is in an array, using a loop I get everything I need, but if it isn't in an array, I get an error or the data are stick together.

I've created a vuex store like this :

const region = {
    state: {
        region: {}
    },
    mutations: {
        SET_REGION(state, region) {
            state.region = region
        }
    },
    actions: {
        getAllRegions({ commit }) {
            axios.get("/api/regions/get")
                .then(response => {
                    commit('SET_REGION', response.data)
                })
        }
    },
    getters: {
        getAllRegions (state) {
            return state.region
        },
        getDelegue (state) {
          return state.region.delegue
        }
    }
};

When I call this data in my page I get this result :

[
 {
  id: 3,
  name: "Occitanie",
  agents: [ ],
  delegue: null
 },
 {
  id: 2,
  name: "Ile de France",
  agents: [ ],
  delegue: null
 },
 {
  id: 4,
  name: "Hauts de France",
  agents: [ ],
  delegue: null
 },
 {
  id: 1,
  name: "Grand Est",
  agents: [
   {
    lastname: "DOE",
    firstname: "John",
    phone: "+331234567890",
    user: {
     email: "[email protected]"
    }
   }
  ],
  delegue: {
   lastname: "DURSLEY",
   firstname: "Jake",
   phone: "+3309987654321",
   user: {
    email: "[email protected]"
   }
  }
 }
]

The result seems good to me. Now in my Vue, I would like to display the data, this is where I get in trouble regarding the "DELEGUE" data.

<div v-for="region in myFunctionToRetrieveJsonData">
    <p>Name: {{ region.name }}</p> // WORKING

    <p v-for="agent in region.agents">
        {{ agent.lastname + ' ' + agent.firstname }}<br> // WORKING
        {{ agent.phone }}<br> // WORKING
        <span v-for="email in agent.user">{{ email }}</span> // WORKING

        // THIS WAY
        Delegue: {{ agent.delegue.lastname + ' ' + agent.delegue.firstname }} // NOT WORKING

        // ALSO THIS WAY
        Delegue: {{ agent.delegue[0].lastname + ' ' + agent.delegue[0].firstname }} // NOT WORKING

        // THE OTHER WAY
        <p v-for="delegue in region.delegue">
            Delegue: {{ delegue }} // DISPLAY: DURSLEYJake+3309987654321{"email":"[email protected]"} NOT GOOD
        </p>
    </p>
</div>

I get this error : Uncaught (in promise) TypeError: Cannot read properties of null (reading 'lastname')

So I understand that for USERS I can do a v-for loop, but in the case of DELEGUE, I can't access right away, or if I do a loop, I've got all the data not separated and I can't work with it.

Do you guys have any idea?

Thank you very much for your help.

Logan

Answer 1

If I understood you correctly, please take a look at following snippet:

new Vue({
  el: '#demo',
  data() {
    return {
      items: [
        {id: 3, name: "Occitanie", agents: [ ], delegue: null},
        {id: 2, name: "Ile de France", agents: [ ], delegue: null},
        {id: 4, name: "Hauts de France", agents: [ ], delegue: null},
        {id: 1, name: "Grand Est", agents: [{lastname: "DOE", firstname: "John", phone: "+331234567890", user: {email: "[email protected]"}}], delegue: {lastname: "DURSLEY", firstname: "Jake", phone: "+3309987654321", user: {email: "[email protected]"}}}
      ]
    }
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="demo">
  <div v-for="region in items">
    <p>Name: {{ region.name }}</p>
    <p v-for="agent in region.agents">
       {{ agent.lastname + ' ' + agent.firstname }}<br> 
       {{ agent.phone }}<br> 
       <span v-for="email in agent.user">{{ email }}</span>
       Delegue: {{region.delegue?.lastname + ' ' + region.delegue?.firstname }}
    </p>
    
  </div>
</div>