Php validation not working. Even with good data (closed) - php

Question

For my website i want to have registration. And everything goes well until it's time for validation. So, i have to this all in different files (validation in validation.php, registration in registration.php and registration form in registrationForm.php). In registration.php i have something like this:
<?php
session_start();
include 'validation.php';
include "mail.php";
include 'dbConnection/dbconn.php';
if (isset($_POST['submit'])) {
$name = $_POST['name'];
$surname = $_POST['surname'];
$username = $_POST['username'];
$password1 = $_POST['password1'];
$password2 = $_POST['password2'];
$email = $_POST['email'];
//sendMail("test", "test");
if (validateName($name) && validateSurname($surname) && validateEmail($email) && validatePassword($password1) && validateUsername($username) && checkIfPasswordsAreMatching($password1, $password2)) {
echo "Worked";
} else {
echo "Not worked";
header("Location: registrationForm.php");
}
} else {
header("Location: registrationForm.php");
}
?>
And my problem is that no matter if i put good data or completely wrong data my validation always says that it's wrong.
Here is my validation code (validation.php):
<?php
session_start();
$allChecked = true;
function validateName($string) {
if (strlen($string) < 2) {
$allChecked = false;
$_SESSION['nameError'] = "Your name is too short. It has to be at least 2 characters long.";
}
if (preg_match('[\W]', $string)) {
$allChecked = false;
$_SESSION['nameError'] = "Your name cannot contain any special character.";
}
return $string;
}
function validatePassword($string) {
if (strlen($string) < 8 || strlen($string) > 20) {
$allChecked = false;
$_SESSION['passwordError'] = "Your password must be between 8 and 20 characters long.";
}
if (preg_match('/(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[#$!%*?&])[A-Za-z\d#$!%*?&]/', $string) == false) {
$allChecked = false;
$_SESSION['passwordError'] = "Your password must contain at least 1 big letter, 1 special character, 1 number and 1 small letter.";
}
return $string;
}
function validateSurname($string) {
if (strlen($string) < 2) {
$allChecked = false;
$_SESSION['surnameError'] = "Your surname is too short. It has to be at least 2 characters long.";
}
if (preg_match('[\W]', $string)) {
$allChecked = false;
$_SESSION['surnameError'] = "Your surname cannot contain any special character.";
}
return $string;
}
function validateUsername($string) {
if (strlen($string) < 2 || strlen($string) > 20) {
$allChecked = false;
$_SESSION['usernameError'] = "Your username must be between 2 and 20 characters";
}
/*
$sql = "SELECT * FROM Users WHERE username = '$string'";
$sql = $conn->query($sql);
$nameExists = $result->fetch();
if($nameExists) {
$allChecked = false;
$_SESSION['usernameError'] = "Name is already taken";
}
*/
return $string;
}
function validateEmail($string) {
$em = filter_var($string, FILTER_VALIDATE_EMAIL);
if (!$em){
$allChecked = false;
$_SESSION['emailError'] = "Your email has to be valid.";
}
/*
$sql = "SELECT * FROM Users WHERE mail = '$string'";
$result = $conn->query($sql);
$emailExists = $result->fetch();
if($emailExists) {
$allChecked = false;
$_SESSION['emailError'] = "Email is already taken";
}
*/
return $allChecked;
}
function checkIfPasswordsAreMatching($password1, $password2) {
if ($password2 != $password1) {
$allChecked = false;
$_SESSION['passwordError'] = "Passwords must be the same";
}
return $allChecked;
}
?>

Answer 1

In each of your return statements check $allChecked and if it has NOT been set return true instead of $allChecked.
return (isset($allChecked) ? $allChecked : true);

Answer 2

In your functions validateName, validateSurname, validatePassword, validateUsername you are returning the original string instead of validation result. In validateEmail and checkIfPasswordsAreMatching you are returning $allChecked but it's not initialized with value if all checks are passed so null is returned instead.
You should rewrite your validation functions to look like this
function validateName($string) {
if (strlen($string) < 2) {
$_SESSION['nameError'] = "Your name is too short. It has to be at least 2 characters long.";
return false;
}
if (preg_match('[\W]', $string)) {
$_SESSION['nameError'] = "Your name cannot contain any special character.";
return false;
}
return true;
}