How to make a simple CORS request?

THE SITUATION:

I am making an app in AngularJs. I need to make a CORS request to fetch data from an api on a different address.

On the api i output a very simple json, for test purpose:

[{"id":0,"name":"First"},{"id":1,"name":"Second"},{"id":2,"name":"Third"}]

I need to fetch these data and display on my app.

$HTTP CALL:

making the $http call i get the following error, because the api is on a different domain:

No 'Access-Control-Allow-Origin' header is present on the requested resource

CORS REQUEST - THE CODE:

// Create the XHR object.
$scope.createCORSRequest = function(method, url)
{
    var xhr = new XMLHttpRequest();

    if ("withCredentials" in xhr) 
    {
        // XHR for Chrome/Firefox/Opera/Safari.
        xhr.open(method, url, true);
    } 
    else if (typeof XDomainRequest != "undefined") 
    {
        // XDomainRequest for IE.
        xhr = new XDomainRequest();
        xhr.open(method, url);
    } 
    else 
    {
        // CORS not supported.
        xhr = null;
    }

    return xhr;
}


// Helper method to parse the title tag from the response.
$scope.getTitle = function(text)
{
    return text.match('<title>(.*)?</title>')[1];
}


// Make the actual CORS request.
$scope.makeCorsRequest = function()
{
    var url = 'http://DOMAIN.COM/main/json_export_test';

    var xhr = $scope.createCORSRequest('GET', url);

    console.log('----- xhr -----');
    console.log(xhr);

    if (!xhr) 
    {
        alert('CORS not supported');
        return;
    }

    // Response handlers.
    xhr.onload = function() 
    {
        var text = xhr.responseText;
        var title = $scope.getTitle(text);
        alert('Response from CORS request to ' + url + ': ' + title);
    };

    xhr.onerror = function() 
    {
        alert('Woops, there was an error making the request.');
    };

    xhr.send();
}

When i run the function makeCorsRequest i get the alert called by xhr.onerror

But i have no clues why it isn't working.

THE API:

This is the very simple php function in the api, for test purpose:

public function json_export_test()
{
    $data = array(
        array(
            "id" => 0,
            "name" => "First"
        ),
        array(
            "id" => 1,
            "name" => "Second"
        ),
        array(
            "id" => 2,
            "name" => "Third"
        )
    );

    echo json_encode($data);
}

THE QUESTION:

How can i make a simple CORS request?

EDIT - THE SOLUTION:

This is how it looks the api after having edited it, thanks to the reply:

public function json_export_test()
{
    header('Access-Control-Allow-Origin: *');

    $data = array(
        array(
            "id" => 0,
            "name" => "First"
        ),
        array(
            "id" => 1,
            "name" => "Second"
        ),
        array(
            "id" => 2,
            "name" => "Third"
        )
    );

    echo json_encode($data);
}