Javascript can't retrieve data from my server

Question

I'm currently working in eclipse and I'm making a component for Lumira designer in JavaScript. Beforehand I made a function that can write away data to my database (this one worked fine).

Now I'm trying to make a function to fetch this data back from the server. The problem is I try to see my data with an alert or in the console log but everytime I fetch something my alert either doesn't pop up or is empty and the console log is also empty. But when I check my network it always says that everything is fetched and I can see my objects(see picture below).

My question is why can't I see them in my alert or console? You can find my code and an image of the network below

Fetch I tried to use:

getButton.on("click", function() {
    fetch('https://xxxxxx/myphpfile.php').then(
        function(response){
            alert(response)
            return response.json();
        }).then(function(jsonData){
            alert(jsonData)
            //handle json data processing here
        });

xmlhttprequest I tried before:

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
    if (xhr.readyState == XMLHttpRequest.DONE) {
        alert(xhr.responseText)
        var resp = xhr.responseText
        arr = JSON.parse(resp);
        alert(arr);
    }
}
xhr.open('GET', 'https://xxxxxx/myphpfile.php', true);
xhr.send(null);

Answer 1

Seems like using an Ajax call did the job for me

var dataOBJECTNAME='';
$.ajax({
            url: 'http://your_webservice/GETALL_OBJECTS',
            data: '',
            success: function (resp) {
                dataOBJECTNAME = resp;

            },
            error: function () {}
        });