vue.js json object array as data - json

Question

aye folks!
I'm currently learning to do stuff with vue.js. unfortunately i'm stuck atm. what i want to do is sending a request to my sample API which responds with a simple json formatted object.
I want to have this object as data in my component – but it doesn't seem to do that for whatever reason.
Ofc i tried to find a solution on stackoverflow but maybe i'm just blind or this is just like the code other people wrote. i even found this example on the official vue website but they're doing the same thing as i do .. i guess?
btw. When i run the fetchData() function in a separate file it does work and i can access the data i got from my API. no changes in the code .. just no vue around it. i'm really confused right now because i don't know what the mistake is.
code:
var $persons = [];
and inside my component:
data: {
persons: $persons,
currentPerson: '',
modal: false
},
created: function() {
this.fetchData()
},
methods: {
fetchData: function () {
var ajax = new XMLHttpRequest()
ajax.open('GET', 'http://api.unseen.ninja/data/index.php')
ajax.onload = function() {
$persons = JSON.parse(ajax.responseText)
console.log($persons[0].fname)
}
ajax.send()
}
},
[...]
link to the complete code

Answer 1

First, make sure that the onload callback is actually firing. If the GET request causes an error, onload won't fire. (In your case, the error is CORS-related, see this post suggested by #Pradeepb).
Second, you need to reference the persons data property directly, not the $persons array that you initialized persons with.
It would look like this (inside your fetchData method):
var self = this;
ajax.onload = function() {
self.persons = JSON.parse(ajax.responseText)
console.log($persons[0].fname)
}