Javascript和PHP JSON异步请求错误

Question

I am always catching errors when sending an async request from my client-side javascript to my web-service php code. No guarantee that I used those terms correctly but I tried. It always catches an error and I think that the php code is not even being called.

function suggestSearch() {
     var value = document.getElementById("filterText").value; //Suchtext
     let reqObj = {method: "getNames", input: value};
     fetch("actions/async_search.php", {method:"POST",body:JSON.stringify(reqObj)})
      .then((response) => {
           if(response.ok) {
                let contentType = response.headers.get("content-type");
                if(contentType && contentType.indexOf("application/json") != -1) {
                     return response.json();
                }
            }
            throw new Error("Error in response!");
      })
      .then((result) => {
           for(var i = 0; i < result.length; i++) {
                 var obj = result[i];
                 console.log(obj.id);
           }
       })
       .catch( (error) => { alert("An error occured!" + error);
       })
}

async_search.php:

 header("Content-Type: application/json");
    $result = ["result" => null];

    $request = file_get_contents("php://input");

    if(isset($request) && !empty($request)) {
        $requestObj = json_decode($request);
        if($requestObj->method == "getNames") {
            $input = $requestObj->input;
            if($input != "") {
                $sql = "SELECT ArtikelName FROM artikel WHERE ArtikelName LIKE ? LIMIT 5;"; 
                $statement = $conn -> prepare($sql); //prepare
                $statement -> execute(array("$input%")); 
                $result = $statement -> fetchall(PDO::FETCH_ASSOC);
                echo json_encode($result);

            }
        }
    }

// EDIT : Now I came so far that I get this as an error:

SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data

Answer 1

I have found the error. When saving to the $result array I have to put the variables in brackets, eg

$result = ["result" => ($row['ArtikelName']), "info" => "Ok"];

before encoding it. I hope this helps someone in the future.