在向Ajax提交表单中没有属性

Question

So I'm trying to submit a form to an Ajax, but looks like this Ajax does't send nothing to my Json, I tested the result of this Ajax and this is the message I've found in the console "No properties".

This is the form:

<form id="formPrueba" method="POST">
        <input type="text" id="film_id">
        <input type="text" id="title">
        <input type="submit" name="sub">
        <button form="formPrueba" onclick="editar()"></button>
</form>

Ajax function:

function editar(){
    event.preventDefault();
    $.ajax({
        method: "POST",
        url: "prueba.php",
        data: $("#formPrueba").serialize(),
        dataType: "json"
    })
        // en caso de éxito
        .done(function (response) {
            // Escribe el mensaje recibido en el JSON descartando el contenido anterior
            console.log("Response de Edit".response);

        })
        // En caso de fallo
        .fail(function (jqXHR, textStatus, errorThrown) {
            alert("Error: " + textStatus);
        });
}

Json (test):

<?php
echo ("Esto es prueba");
echo json_encode($_POST);

Json:

<?php
include "class/Film.php";
require_once "class/DBSingleton.php";
//Json
$film_id = (isset($_POST['film_id'])? $_POST['film_id'] : null);
$title = (isset($_POST['title'])? $_POST['title'] : null);
$description = (isset($_POST['description'])? $_POST['description'] : null);
$release_year = (isset($_POST['release_year'])? $_POST['release_year'] : null);
$language_id = (isset($_POST['language_id'])? $_POST['language_id'] : null);
$original_language_id = (isset($_POST['original_language_id'])? $_POST['original_language_id'] : null);
$rental_duration = (isset($_POST['rental_duration'])? $_POST['rental_duration'] : null);
$rental_rate = (isset($_POST['rental_rate'])? $_POST['rental_rate'] : null);
$length = (isset($_POST['length'])? $_POST['length'] : null);
$replacement_cost = (isset($_POST['replacement_cost'])? $_POST['replacement_cost'] : null);
$rating = (isset($_POST['rating'])? $_POST['rating'] : null);
$special_features = (isset($_POST['special_features'])? $_POST['special_features'] : null);
$image = (isset($_POST['image'])? $_POST['image'] : null);
$last_update = (isset($_POST['last_update'])? $_POST['last_update'] : null);

switch ($_POST["action"]) {
    case 'listado':
        try {
            $response["msg"]="Listado de las Peliculas.";
            $response["success"]=true;
            $response["data"]=Film::list();
        } catch (Exception $e) {
            $response["success"]=false;
        }
        echo json_encode($response); 
    break;
    case 'insert':
        try {
            $response["msg"]="Insertar.";
            $response["success"]=true;
            $instanciaPelicula=new Film($film_id,$title,$description,$release_year,$language_id,$original_language_id,$rental_duration,$rental_rate,$length,$replacement_cost,$rating,$special_features,$image,$last_update);
            $instanciaPelicula->insert();  
        } catch (Exception $e) {
            $response["success"]=false;
        }  
        echo json_encode($response); 
    break;
    case 'delete':
        try {
            $response["msg"]="Eliminar.";
            $response["success"]=true;
            $instanciaPelicula=new Film($film_id);
            $instanciaPelicula->delete();
        } catch (Exception $e) {
            $response["success"]=false;
        }  
        echo json_encode($response); 
    break;
    case 'update':
        try {
            $response["msg"]="Actualizar.";
            $response["success"]=true;
            $instanciaPelicula=new Film($film_id,$title,$description,$release_year,$language_id,$original_language_id,$rental_duration,$rental_rate,$length,$replacement_cost,$rating,$special_features,$image,$last_update);
            $instanciaPelicula->update();
            echo ($film_id.$title);
        } catch (Exception $e) {
            $response["success"]=false;
        }  
        echo json_encode($response); 
    break;
    case 'paginacion':
        try {
            $response["msg"]="Paginar.";
            $response["success"]=true;
            $peliculas=Film::paginacion();
        } catch (Exception $e) {
            $response["success"]=false;
        }  
        echo json_encode($response); 
    break;
    case 'select':
        try {
            $response["msg"]="Seleccionar.";
            $response["success"]=true;
            $response["data"]=Film::select($film_id);
        } catch (Exception $e) {
            $response["success"]=false;
        }  
        echo json_encode($response); 
    break;
    default:
        # code...
    break;
}

This Ajax belongs to Update part, there I have a function to update the object from a database.

Answer 1

In your update case's try block, you are spoiling the echo'ed json format because you are echoing ($film_id.$title) .

Whenever you want to deliver valid json to your ajax technique, there must be no other text to interfere.

If you want to pass additional data, it needs to be built into your json string (not simply appended before it).

If you open your browser's dev tools and inspect the XHR tab's details, you should see how the json string is corrupted which causes your process to fail.

From https://api.jquery.com/serialize/ :

Note: Only "successful controls" are serialized to the string. No submit button value is serialized since the form was not submitted using a button. For a form element's value to be included in the serialized string, the element must have a name attribute. Values from checkboxes and radio buttons (inputs of type "radio" or "checkbox") are included only if they are checked. Data from file select elements is not serialized.

So you need to add a couple of name attributes to your form fields.

Answer 2

You've already got a correct answer here, but I wanted to make some comment on your code.

First point, since PHP 7.0 (released 4 years ago) we have had the null coalesce operator , to make your variable assignments from POST much shorter. Second, the idea of DRY means not repeating code over and over again, like you are doing with your calls to json_encode() . Third, whitespace and formatting make a huge difference to how easy your code is to read, and work with. Here's how I would improve your code:

<?php
include "class/Film.php";
require_once "class/DBSingleton.php";
//Json
$film_id              = $_POST['film_id'] ?? null;
$title                = $_POST['title'] ?? null;
$description          = $_POST['description'] ?? null;
$release_year         = $_POST['release_year'] ?? null;
$language_id          = $_POST['language_id'] ?? null;
$original_language_id = $_POST['original_language_id'] ?? null;
$rental_duration      = $_POST['rental_duration'] ?? null;
$rental_rate          = $_POST['rental_rate'] ?? null;
$length               = $_POST['length'] ?? null;
$replacement_cost     = $_POST['replacement_cost'] ?? null;
$rating               = $_POST['rating'] ?? null;
$special_features     = $_POST['special_features'] ?? null;
$image                = $_POST['image'] ?? null;
$last_update          = $_POST['last_update'] ?? null;

// assume true, so you don't have to type it every time
$response = ["success" => true];

// since we are checking for exceptions in every block, just wrap it all in one try block
try {

    switch ($_POST["action"]) {
        case 'listado':
            $response["msg"] = "Listado de las Peliculas.";
            $response["data"] = Film::list();
        break;

        case 'insert':
            $response["msg"] = "Insertar.";
            // you can't read lines that are 300 characters long
            $instanciaPelicula = new Film(
                $film_id, $title, $description, $release_year, $language_id,
                $original_language_id, $rental_duration, $rental_rate, $length,
                $replacement_cost, $rating, $special_features, $image, $last_update
            );
            $instanciaPelicula->insert();
        break;

        case 'delete':
            $response["msg"] = "Eliminar.";
            $instanciaPelicula = new Film($film_id);
            $instanciaPelicula->delete();
        break;

        case 'update':
            $response["msg"] = "Actualizar.";
            $instanciaPelicula = new Film(
                $film_id, $title, $description, $release_year, $language_id,
                $original_language_id, $rental_duration, $rental_rate, $length,
                $replacement_cost, $rating, $special_features, $image, $last_update
            );
            $instanciaPelicula->update();
        break;

        case 'paginacion':
            $response["msg"] = "Paginar.";
            $peliculas=Film::paginacion();
        break;

        case 'select':
                $response["msg"] = "Seleccionar.";
                $response["data"] = Film::select($film_id);
        break;

        default:
            # code...
        break;
    }

} catch (Exception $e) {
    $response["success"] = false;
    // you may not want to use the message directly, but you should
    // have some indication from the server of what the error was
    $response["error"] = $e->getMessage();
}

// set the correct header for the data you're sending
header("Content-Type: application/json");
echo json_encode($response);