Http Get和PHP

Question

On my website, I'm using ajax to send data to an external php script, which queries a database and returns the result to the website. I ran into the problem, that I can only return strings with php, but I want to return an array of objects (which is valid json). My code looks like this at the moment:

php

$connection = mysqli_connect($adrs, $usr, $pw, $db);

if(mysqli_connect_errno()) {
 die(mysqli_connect_error());
}

if($_GET["feed"] == "hausaufgaben") {
 $query = "SELECT fach, aufgabe, datum FROM hausaufgaben WHERE fachgruppe != '";
 if($_GET["fremdsprache"] == "latein") {
  $query .= "französisch";
 }
 else {
  $query .= "latein";
 }
 $query .= "' AND fachgruppe != '";
 if($_GET["englisch"] == "koch") {
  $query .= "schopper";
 }
 else {
  $query .= "koch";
 }
 $query .= "' AND datum > '" . date("Y-m-d") . "' ORDER BY datum ASC;";

 $result = mysqli_query($connection, $query);

 $data = [];

 while($row = mysqli_fetch_row($result)) {
  $object = '{"fach": "' . $row[0] . '", "datum": "' . $row[2] . '", "aufgabe": "' . $row[1] . '"}';
  array_push($data, json_decode($object));
 }

 echo $data;
}

ajax

$.ajax({
    type: "GET",
    url: "php/getFeed.php",
    cache: false,
    dataType: "json",
    data: {feed: "hausaufgaben", fremdsprache: this.fremdsprache, englisch: this.englisch}
})
.done(function(data, textStatus, jqXHR) {
    alert(typeof(data));
    this.hausaufgaben = data;
})
.fail(function(jqXHR, textStatus, error) {
    alert("error: " + error);
});

It always throws the error "Unexpected token A". I got it to return each single line in the array as string, but I can't use a string in my website. My problem is, that I can't echo an array of objects with php and get the array with ajax.

Answer 1

Instead of trying to build a json string yourself you can do it all much easier by building the $data array using PHP data structures and then using json_encode() to convert it all to a JSON string for sending to your javascript.

Reference json_encode and json_decode

Like this :-

$data = [];

while($row = mysqli_fetch_object($result)) {
    $data[] = $row;
}

echo json_encode($data);

You will also have to change you javascript to process an array of objects rather than a string, but that should be easy