Vue JS returns [__ob__: Observer] data instead of

Question

I've created a page where I want to get all my data from the database with an API call, but I'm kinda new to VueJS and Javascript aswell and I don't know where I'm getting it wrong. I did test it with Postman and I get the correct JSON back.

This is what I get:

[__ob__: Observer]
length: 0
__ob__: Observer {value: Array(0), dep: Dep, vmCount: 0}
__proto__: Array

This is what I want:

(140) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, …]
[0 … 99]
[100 … 139]
length: 140
__ob__: Observer {value: Array(140), dep: Dep, vmCount: 0}
__proto__: Array

Thats my Vue template file:

<template>
    <div>
        <h2>Pigeons in the racing loft</h2>
        <div class="card-content m-b-20" v-for="pigeon in pigeons" v-bind:key="pigeon.id">
            <h3>{{ pigeon.id }}</h3>
        </div>
    </div>
</template>

<script>
export default {
    data(){
        return{
            pigeons: [],
            pigeon: {
                id: '',
                sex: '',
                color_id: '',
                pattern_id: '',
                user_id: '',
                loft_id: '',
                country: '',
                experience: '',
                form: '',
                fatique: ''
            },
            pigeon_id: ''
        }
    },
    created(){
        this.fetchPigeons();
        console.log(this.pigeons); // Here I got the observer data instead my array
    },

    methods: {
        fetchPigeons(){
            fetch('api/racingloft')
            .then(res => res.json())
            .then(res => {
                console.log(res.data); // Here I get what I need
                this.pigeons = res.data;
            })
        }
    }
}
</script>

I've tried to do it with axios aswell, but it gave me exactly the same thing. When I console it from the method it gives my data, but outside it just gives nothing.

Answer 1

Thank you for all your suggestion. Things worked on my end by just using "const".

const cookieInfo = ToolCookieService.getToolNumbersFromCookie();

Thanks, Ranjit

Answer 2

I got the same problem still stuck ...

Wrote these according to Evan(Vue Author) JSON.parse(JSON.stringify(res.data)) method, But why can't normal data?

  methods: {
    async getdata() {
      console.log(1);
      await axios.get(API).then((res) => {
          console.log(2);
          if (!this.dataList.length) {
            this.dataList = JSON.parse(JSON.stringify(res.data));
            console.log(3);
            console.log(res.data, 'res.data ');
            console.log(this.dataList, 'this.dataList')
            console.log('----------check-----------',JSON.parse(JSON.stringify(res.data)));
          }
        })
        .catch(err => {
          console.error('failed: ' + err);
        })
      console.log(4);
    },

Answer 3

Here is my solution:

add new method something like log to your $root component. App.vue's created is recommended:

this.$root.log = function log() {
  for (let i = 0; i < arguments.length; i += 1) {
    if (typeof (arguments[i]) === 'object') {
      try {
        arguments[i] = JSON.parse(JSON.stringify(arguments[i]));
      } catch (e) {
        console.error(e);
      }
    }
  }
  console.log(...arguments);
};

just call this.$root.log(this.pigeons) in your component.

My result:

BEFORE:

AFTER:

Answer 4

This happens because Vue js convert every item in the data to something that can be observed. So it makes sense if you console log something in the data. The output will be something wrapped into an observer.

To have a better vision on your data I suggest you to install the Vue dev tools. https://chrome.google.com/webstore/detail/vuejs-devtools/nhdogjmejiglipccpnnnanhbledajbpd?hl=en

Answer 5

If your goal is debugging WHAT included in Observer Vue instance, this is my solution:

Print out that variable in template block belongs to your Component

After that, you can reformat the structure of the output to observe the detail.

For example:

<template>
  <div>
    {{ pigeons }}
  <div>
</template>

Another way, if you wanna see it in console, you should put the console.log into mounted phase. Because at created phase, the this.pigeons still be empty. Ref: https://vuejs.org/v2/guide/instance.html#Lifecycle-Diagram

Hope this helpful.

Answer 6

Well I had exactly same problem but I solved it:

Just move app.js external link to head tag.