PHP OOP - How to validate input fields correctly - php

Question

This is my Form - This an Include File.
form_file.php
<section class="container-sm">
<form method="post" class="par-form">
<h3 class="par-h2">John Doe Form</h3>
<p><label class="single-label" for='user_firstname'>Name: <a id='user_firstname_label'></a></label>
<input class="par-input form_login" maxlength="15" name="user_firstname" required value="<?=$obVaga->user_firstname?>" ></input><span class="error">*<?php echo $nameErr;?></span></p>
<p><label class="single-label" for='user_secondname'>Surname: <a id='user_secondname_label'></a></label>
<input class="par-input form_login" maxlength="40" name="user_secondname" required value="<?=$obVaga->user_secondname?>" ></input></p>
<p><label class="single-label" for='user_email'>E-mail: <a id='user_email_label'></a></label>
<input class="par-input form_login" maxlength="40" name="user_email" required value="<?=$obVaga->user_email?>" ></input></p>
<button type="button" onclick="sendData()" class="par-button" id='user_button_sendData'>SEND</button>
</form>
</section>
This is the template page that receives the Form file
single-add.php
<?php
/**
* Acess the composer library
*/
require __DIR__.'/vendor/autoload.php';
/**
* Use a Classe VAGA
*/
use \App\Entity\Vaga;
$obVaga = new Vaga;
if (isset($_POST['user_firstname'],$_POST['user_secondname'],$_POST['user_email'])) {
$obVaga->user_firstname = $_POST['user_firstname'];
$obVaga->user_secondname = $_POST['user_secondname'];
$obVaga->user_email = $_POST['user_email'];
$obVaga->user_cadastrar();
}
?>
<!-- Receive the contents of the form include form_file.php -->
<?php include __DIR__.'/appincludes/form_file.php' ?>
This is the Class page that receives the data
Vaga.php
<?php
namespace App\Entity;
/**
* Use a Classe Database
*/
use \App\Db\Database;
use PDO;
class Vaga{
// #var Integer
public $user_id;
// #var String
public $user_firstname;
// #var String
public $user_secondname;
// #var String
public $user_email;
// #var String
public $nameErr;
// #var Boolean
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["user_firstname"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["user_firstname"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z-' ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
}
if (empty($_POST["user_secondname"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["user_secondname"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z-' ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
}
if (empty($_POST["user_email"])) {
$emailErr = "Email is required";
} else {
$email = test_input($_POST["email"]);
// check if e-mail address is well-formed
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Invalid email format";
}
}
}
public function user_cadastrar(){
// DEFINIR A DATA
// INSERT STRINGs IN THE TABLE
$obDatabase = new Database('tb_partner');
$this->id = $obDatabase->insert([
'user_firstname' => $this->user_firstname,
'user_secondname'=> $this->user_secondname,
'user_email' => $this->user_email
]);
}
}
I´m trying to use this script to validate the fields, but I am stuck. I`m trying to execute this script through the class file Vaga.php
public function par_add_validate(){
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["user_firstname"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["user_firstname"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z-' ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
}
if (empty($_POST["user_secondname"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["user_secondname"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z-' ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
}
if (empty($_POST["user_email"])) {
$emailErr = "Email is required";
} else {
$email = test_input($_POST["email"]);
// check if e-mail address is well-formed
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Invalid email format";
}
}
};
}
I putted the Var $nameErr in the form_file.php where it should display an echo string IF the field is empty or with not acceptable letters.
This is the result in the debug.log file:
[18-Aug-2021 16:44:07 UTC] PHP Notice: Undefined variable: nameErr in C:\xampppserver2\htdocs\project\appincludes\form_file.php on line 15
Line 15:
<input name="user_firstname" required value="<?=$obVaga->user_firstname?>" ></input><span>*<?php echo $nameErr;?></span></p>
What am I doing wrong or what is missing?

Answer 1

I believe you have some lines missing here:
// #var Boolean
if ($_SERVER["REQUEST_METHOD"] == "POST") {
Otherwise you've put some logic code right inside your class (without method) which should result in a Parse error. Also why is there #var Boolean with no boolean property following?
Given that you wrap all that code in a method, you still have several issues. First, you can't access $nameErr directly. Instead, you want $this->nameErr.
And in form_file.php you also have no variable called $nameErr. You have nameErr as a property of $obVaga object though. You can access it using $obVaga->nameErr.