how to show php validations error on page - php

Question

I have a form and all the validations, now I want to show the error messages in front of the text field not in the url. How do I do this?
Here is my PHP code:
<?php
if ((isset($_POST['submit']))){
$email = strip_tags($_POST['email']);
$fullname = strip_tags($_POST['fullname']);
$username = strip_tags($_POST['username']);
$password = strip_tags($_POST['password']);
$fullname_valid = $email_valid = $username_valid = $password_valid = false;
if(!empty($fullname)){
if (strlen($fullname) > 2 && strlen($fullname)<=30) {
if (!preg_match('/[^a-zA-Z\s]/', $fullname)) {
$fullname_valid = true;
# code...
}else {$fmsg .="fullname can contain only alphabets <br>";}
}else{$fmsg1 .="fullname must be 2 to 30 char long <br>";}
}else{$fmsg2 .="fullname can not be blank <br>";}
if (!empty($email)) {
if (filter_var($email , FILTER_VALIDATE_EMAIL)) {
$query2 = "SELECT email FROM users WHERE email = '$email'";
$fire2 = mysqli_query($con,$query2) or die("can not fire query".mysqli_error($con));
if (mysqli_num_rows($fire2)>0) {
$msg .=$email."is already taken please try another one<br> ";
}else{
$email_valid=true;
}
# code...
}else{$msg .=$email."is an invalid email address <br> ";}
# code...
}else{$msg .="email can not be blank <br>";}
if(!empty($username)){
if (strlen($username) > 4 && strlen($username)<=15) {
if (!preg_match('/[^a-zA-Z\d_.]/', $username)) {
$query = "SELECT username FROM users WHERE username = '$username'";
$fire = mysqli_query($con,$query) or die("can not fire query".mysqli_error($con));
if(mysqli_num_rows($fire)> 0){
$umsg ='<p style="color:#cc0000;">username already taken</p>';
}else{
$username_valid = true;
}
# code...
# code...
}else {$msg.= "username can contain only alphabets <br>";}
}else{$msg.= "username must be 4 to 15 char long <br>";}
}else{$msg.="username can not be blank <br>";}
if (!empty($password)) {
if (strlen($password) >=5 && strlen($password) <= 15 ) {
$password_valid = true;
$password = md5($password);
# code...
}else{$msg .= $password."password must be between 5 to 15 character long<br>";}
# code...
}else{$msg .= "password can not be blank <br>";}
if ($fullname_valid && $email_valid && $password_valid && $username_valid) {
$query = "INSERT INTO users(fullname,email,username,password,avatar_path) VALUES('$fullname','$email','$username','$password','avatar.jpg')";
$fire = mysqli_query($con,$query) or die ("can not insert data into database".mysqli_error($con));
if ($fire){
header("Location: dashboard.php");}
}else{
header("Location: createaccount.php?msg=".$msg);
}
}
?>
and this is my html code:
<div class="container">
<form name="signup" id="signup" method="POST">
<h2>sign up</h2>
<div class="form-input">
<input name="email" type="email" name="email" id="email" placeholder="enter email" required="email is required">
</div>
<input name="mobile" type="number" id="mobile" placeholder="enter mobile number" required="mobile is required">
<span id="message"></span>
<div class="form-input">
<input name="fullname" type="full name" id="fullname" name="full name" placeholder="full name" required="what's your fullname">
</div>
<div>
<input name="username" type="username" id="username" name="username" placeholder="username" required="username is required">
</div>
<div>
<input name="password" type="password" id="password" name="password" placeholder="password" required="password is required">
</div>
<div>
<input type="submit" name="submit" id="submit"
value="sign up" class="btn btn-primary btn-block">
forgot password?
<h3>have an account? log in</h3>
</div>
</form>
How do I get the error message in front of my text field, and also how do I get the specified error in front of the specified text field? I don't want to use ajax or javascript. I want to do it with PHP. I have tried this but no luck.
<?php if(isset($errorfname)) { echo $errorfname; } ?>

Answer 1

send msg to get params is not good idea.
Use session
$_SESSION['error_msg'] = $msg
header("Location: createaccount.php");
and add get error in php
$errors = '';
if(isset($_SESSION['error_msg'])) { $errors = $_SESSION['error_msg']; } ?>
and in html show $errors

Answer 2

By looking at your form does not have an action attribute therefore one can concluded that you are submitting the form at the same page as the form PHP_SELF
So if you want to display the error next to the field I would advice that you first declare an empty variables for each text error on top of your page then echo the variables next to each field.
<?php
$emailError = "";
$fullnameError = "";
$usernameError = "";
$passwordError = "";
$errors = 0;
if ((isset($_POST['submit']))) {
$email = strip_tags($_POST['email']);
$fullname = strip_tags($_POST['fullname']);
$username = strip_tags($_POST['username']);
$password = strip_tags($_POST['password']);
$fullname_valid = $email_valid = $username_valid = $password_valid = false;
if (!empty($fullname)) {
if (strlen($fullname) > 2 && strlen($fullname) <= 30) {
if (!preg_match('/[^a-zA-Z\s]/', $fullname)) {
$fullname_valid = true;
# code...
} else {
$fullnameError = "fullname can contain only alphabets <br>";
$errors++;
}
} else {
$fullnameError = "fullname must be 2 to 30 char long <br>";
$errors++;
}
} else {
$fullnameError = "fullname can not be blank <br>";
$errors++;
}
if (!empty($email)) {
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
$query2 = "SELECT email FROM users WHERE email = '$email'";
$fire2 = mysqli_query($con, $query2) or die("can not fire query" . mysqli_error($con));
if (mysqli_num_rows($fire2) > 0) {
$emailError = $email . "is already taken please try another one<br> ";
} else {
$email_valid = true;
}
# code...
} else {
$emailError = $email . "is an invalid email address <br> ";
$errors++;
}
# code...
} else {
$emailError = "email can not be blank <br>";
}
if (!empty($username)) {
if (strlen($username) > 4 && strlen($username) <= 15) {
if (!preg_match('/[^a-zA-Z\d_.]/', $username)) {
$query = "SELECT username FROM users WHERE username = '$username'";
$fire = mysqli_query($con, $query) or die("can not fire query" . mysqli_error($con));
if (mysqli_num_rows($fire) > 0) {
$usernameError = '<p style="color:#cc0000;">username already taken</p>';
$errors++;
} else {
$username_valid = true;
}
} else {
$usernameError = "username can contain only alphabets <br>";
$errors++;
}
} else {
$usernameError = "username must be 4 to 15 char long <br>";
$errors++;
}
} else {
$usernameError = "username can not be blank <br>";
$errors++;
}
if (!empty($password)) {
if (strlen($password) >= 5 && strlen($password) <= 15) {
$password_valid = true;
$password = md5($password);
# code...
} else {
$passwordError = $password . "password must be between 5 to 15 character long<br>";
$errors++;
}
# code...
} else {
$passwordError = "password can not be blank <br>";
$errors++;
}
//if there's no errors insert into database
if ($errors <= 0) {
if ($fullname_valid && $email_valid && $password_valid && $username_valid) {
$query = "INSERT INTO users(fullname,email,username,password,avatar_path) VALUES('$fullname','$email','$username','$password','avatar.jpg')";
$fire = mysqli_query($con, $query) or die("can not insert data into database" . mysqli_error($con));
if ($fire) {
header("Location: dashboard.php");
}
}
}
}
?>
<div class="container">
<form name="signup" id="signup" method="POST">
<h2>sign up</h2>
<div class="form-input">
<input name="email" type="email" name="email" id="email" placeholder="enter email" required="email is required">
<!-- display email error here -->
<?php echo $emailError?>
</div>
<input name="mobile" type="number" id="mobile" placeholder="enter mobile number" required="mobile is required">
<span id="message"></span>
<div class="form-input">
<input name="fullname" type="full name" id="fullname" name="full name" placeholder="full name" required="what's your fullname">
<?php echo $fullnameError?>
</div>
<div>
<input name="username" type="username" id="username" name="username" placeholder="username" required="username is required">
<?php echo $usernameError?>
</div>
<div>
<input name="password" type="password" id="password" name="password" placeholder="password" required="password is required">
<?php echo $passwordError?>
</div>
<div>
<input type="submit" name="submit" id="submit" value="sign up" class="btn btn-primary btn-block">
forgot password?
<h3>have an account? log in</h3>
</div>
</form>
NB: I would advice that you look into password_hash() and
password_verify()to hash your passwords, they provide better
security as compared tomd5()` and make sure your database column is
atleast 60 characters in length.. I would also advice to look into
prepared statements.
The following can help :
How can I prevent SQL injection in PHP?
Using PHP 5.5's password_hash and password_verify function

Answer 3

I think the best way is include from template in result
if ($fire){
header("Location: dashboard.php");
}else{
include("createaccount.php");
}
And in createaccount.php
<div class="container">
<form name="signup" id="signup" method="POST">
<h2>sign up</h2>
<p class="errors"><?= $msg ?></p>
...