I've made a get request using Axios which returns some data as expected, but I cannot access the app's data properties in the mounted function to assign the results of the request. The console log to this.productList returns undefined. Can anyone point me in the right direction?

new Vue({
    el: '#products',
    data: function(){
        return{
            test: 'Hello',
            productList: null
        }
    },
    mounted: function(){
        axios.get('.json').then(function(response){
            console.log(response.data);
            console.log(this.productList)
        }).catch(function(error){
            console.log(error);
        })
    }
    
})

I've made a get request using Axios which returns some data as expected, but I cannot access the app's data properties in the mounted function to assign the results of the request. The console log to this.productList returns undefined. Can anyone point me in the right direction?

new Vue({
    el: '#products',
    data: function(){
        return{
            test: 'Hello',
            productList: null
        }
    },
    mounted: function(){
        axios.get('https://api.coindesk.com/v1/bpi/currentprice.json').then(function(response){
            console.log(response.data);
            console.log(this.productList)
        }).catch(function(error){
            console.log(error);
        })
    }
    
})

• javascript
• vue.js
• vuejs2
• axios

• Possible duplicate of How to access the correct `this` inside a callback? – t.niese Commented Aug 20, 2018 at 11:25

1 Answer 1

Because in that function, this doesn't refer to your vue instance. It has another meaning.

You can make a temporary variable to hold the value of this in the outer function, like this:

mounted: function() {

  let $vm = this;

  axios.get('https://api.coindesk.com/v1/bpi/currentprice.json').then(function(response) {
    console.log(response.data);
    console.log($vm.productList)
  }).catch(function(error) {
    console.log(error);
  })
}

Or you can use the nicer arrow functions:

mounted: function() {

  axios.get('https://api.coindesk.com/v1/bpi/currentprice.json').then((response) => {
    console.log(response.data);
    console.log(this.productList)
  }).catch(function(error) {
    console.log(error);
  })
}