Vuejs Fetch Request returns data but attributes as

Question

I am playing around with Vuejs in our project. I have used the same technique in my other project and its working. But here I am not able to assign the data return by the fetch request to a json resource.

When I try to access data returned in then and put it in alert it does gives me the data objects. but I want to assign it to my data attribute packages array.

Here is my component code

<template>
 <div id="packages">
    <div class='radio' v-for="package in packages">
        <label>
            <input type='radio' name='packageradio' v-bind:value="package.id">{{ package.quantity }}
            <span id='price-tag'>{{ package.price }}</span>
        </label>
    </div>
 </div>
</template>
<script>
export default {
    data(){
        return {
            packages:[]
        }
    },
    created(){
        this.fetchPackages();
    },
    methods: {
        fetchPackages: function(){
            fetch('/die-cut/size/4/packages')
                .then(res => res.json())
                .then(function(res){
                    alert("i am hit");
                    this.packages = res;
                })
                .catch(err => console.log(err));
        }
    }
}
</script>

This is the api:

[
{
"id": 1,
"quantity": 50,
"price": 400,
"saving": 100,
"size_id": 4,
"sticker_id": 2,
"created_at": "2018-02-21 17:48:46",
"updated_at": "2018-02-21 17:48:46"
},
{
"id": 2,
"quantity": 100,
"price": 900,
"saving": 100,
"size_id": 4,
"sticker_id": 2,
"created_at": "2018-02-21 17:50:43",
"updated_at": "2018-02-21 17:50:43"
}
]

Answer 1

The data for packages should be working fine. The problem I see in your code is with the following html:

<label>
   <input type='radio' name='packageradio' v-bind:value="package.id">
   {{ package.quantity }}
   <span id='price-tag'>{{ package.price }}</span>
</label>

From the documentation for the label element:

label can permit the Phrasing content, but no descendant label elements. No labelable elements other than the labeled control are allowed.

So, in your code having input a flow content is the key issue.

---

The issue with your code is:

.then(function(res){
   alert("i am hit");
   this.packages = res; 
   // this isn't referenced to the vue instance from the function scope
 })

Replace it with this:

.then(res => { // access parent scope
   alert("i am hit");
   this.packages = res; // now, this will access the vue instance
 })

Answer 2

I think its to do with your this keyword so, either use the ES5 syntax or do some thing like this

fetchPackages: function(){
       var vm = this
        fetch('/die-cut/size/4/packages')
            .then(res => res.json())
            .then(function(res){
                alert("i am hit");
                vm.packages = res;
            })
            .catch(err => console.log(err));
    }

Or off course you can go ahead and do something like this,

fetchPackages(){
        fetch('/die-cut/size/4/packages')
            .then(res => res.json())
            .then((res) => {
                alert("i am hit");
                this.packages = res;
            })
            .catch(err => console.log(err));
    }