PHP - Validations In Forms Are Not Working! (help)

Hi,

I built this reg-login file.

Note, login.php asks for your login details. The webform (so to speak) uses SELECT sql query to check your login credentials.

The reg.php asks for your new acc details. The webform (so to speak) uses INSERT sql query to add your details to db.

I got my webform not displayed to you either as registration form or login form. It is a neutral form. It justs asks you for your email.

Then checks against db. If it exists, it assumes you existing member and login() function takes over and logs you in. Else, registration() functions takes over and registers you.

Note:

On the login(), at the end when user is logged into his member account, his personal details get displayed on screen.
I need you to check if this following line (especially) is correct or not:

if($row = mysqli_fetch_array($result_3,MYSQLI_ASSOC))

1. I want you to see if there any errors in my code that will result in malfunction or hacker sql injecting or hacking.

2. I need you to show me how to VALIDATE user input. VALIDATE email using 1). html5 & 2). php 7 email validation function plus 3.) with REGEX so nothing but email is inputted. Show me these 3 ways to check for email.

I need you to show me how to VALIDATE user password. VALIDATE password using 1). html5 & 2). php 7 & 3.) with REGEX so nothing but password (A-Z, 0-9 ONLY) is inputted. And no other chars. Show me these 3 ways to check for password.

From there,  I should pick on fast from you and manage to VALIDATE username input.

I don't know how to do these above 2 so kindly teach me by showing snippet with comments so i understand your snippet.

NOTE:

I did not complete the password prompt because I have forgotten how to do it with SHA256. Can someone show me a typical example how to query for password with SHA256 or whatever the latest strong algorithm is ? Show me code with comments so I understand what you doing with your code.
I will the modify your snippet a little to suit my purpose and add it on the login().
I know I need to add the password prompt on the registration() too but you don't have to deal with that as I will complete it once I finish learning from you. You just teach me how to do it in the login() and from there I will take it on to add it on the registration().

Thank You!

<?php
	session_start();
	if($_SERVER['REQUEST_METHOD'] == 'POST')
{
    if(!isset($_POST['email_account']) || !isset($_POST['email_service']))
    {
        $email_error = "<font color='red'>Input Email Address!</color>";
    }
    else
    {
        //Connect to Database. (DB_SERVER, BD_USERNAME, DB_PASSWORD, DB_NAME).
        $conn = mysqli_connect("localhost","root","","powerpage");
        $conn->set_charset('utf8mb4'); //Always set Charset.
        
        if($conn === false)
        {
            die("ERROR: Connection Error!. " . mysqli_connect_error());
        }
        else
        {
            //Set Parameters.
            $email = trim($_POST["email_account"]) . '@' . trim($_POST["email_service"]);
            $_SESSION['email'] = trim($_POST["email_account"]) . '@' . trim($_POST["email_service"]);//If this fails on test then replace it with above line
            echo "line 25 triggered: $email<br>";
            
            $sql_query = "SELECT COUNT(personal_email) FROM users WHERE personal_email = ?";
            $stmt = mysqli_prepare($conn,$sql_query);
            if($stmt == False)
            {
                //Close Connection.
                mysqli_close($conn);
                echo "Line 33<br>";//DELETE THIS
                die("<pre>Mysqli Prepare Failed!\n".mysqli_stmt_error($stmt)."\n$sql_query</pre>");
            }
            else
            {
                mysqli_stmt_bind_param($stmt,'s',$email);
                
                if(!mysqli_stmt_execute($stmt))
                {
                    //Close Connection.
                    mysqli_close($conn);                    
                    die("Could not mysqli_stmt_execute! Please try again later!");
                }
                
                $result = mysqli_stmt_get_result($stmt);
                
                if(mysqli_fetch_array($result, MYSQLI_NUM)[0])//WHY THIS NOT WORK UNLESS NUM ARRAY GIVEN ?
                {
                    echo "Line 57 triggered: Function login() will trigger!<br>"; //DELETE THIS
                    $_SESSION['session_type'] = 'login';
                    login();
                
                }
                else
                {
                    echo "Line 61 triggered: Function register() will trigger!<br>"; //DELETE THIS
                    $_SESSION['session_type'] = 'register';
                    register();
                }
            }
        }
    }
}
	function register()
{
    //if(!isset($_SESSION['session_type'] or $_SESSION['session_type'] != 'registration')//Nog Dog's copied & pasted line
    if(!isset($_SESSION['session_type']) || $_SESSION['session_type'] != 'register')
    {
        //Close Statement.
        mysqli_stmt_close($stmt);
        //Close Connection.
        mysqli_close($conn);
        
        die("Line 86: Could not check email! Please try again later!");
    }
    
    //$email = trim($_POST["email_account"]) . '@' . trim($_POST["email_service"]);
    $email = $_SESSION['email'];//If this fails on test then replace it with above line
    
    //Connect to Database. (DB_SERVER, BD_USERNAME, DB_PASSWORD, DB_NAME).
    $conn = mysqli_connect("localhost","root","","powerpage");
    
    //Prepare an INSERT Statement.
    $sql_query_2 = "INSERT INTO users (personal_email) VALUES (?)";
    
    if(!$stmt_2 = mysqli_prepare($conn,$sql_query_2))
    {
        //Close Connection.
        mysqli_close($conn);
        die("Could not register! Please try again later!");
    }
    else
    {
        //Bind Variables to the Prepared Statement as parameters.
        mysqli_stmt_bind_param($stmt_2,'s',$email);
        
        //Attempt to execute the Prepared Statement.
        if(!mysqli_stmt_execute($stmt_2))
        {
            //Close Statement.
            mysqli_stmt_close($stmt_2);
            //Close Connection.
            mysqli_close($conn);
            die("Could not register! Please try again later!");
        }
        mail();
    }
}
	function login()
{
    if(!isset($_SESSION['session_type']) || $_SESSION['session_type'] != 'login')
    {
        //Close Statement.
        mysqli_stmt_close($stmt);                
        //Close Connection.
        mysqli_close($conn);
        
        die("Could not check email! Please try again later!");
    }
    
    //$email = trim($_POST["email_account"]) . '@' . trim($_POST["email_service"]);
    $email = $_SESSION['email'];//If this fails on test then replace it with above line
    
    //Connect to Database. (DB_SERVER, BD_USERNAME, DB_PASSWORD, DB_NAME).
    $conn = mysqli_connect("localhost","root","","powerpage");
    
    //Prepare a Select Statement.
    $sql_query_3 = "SELECT id,username,first_name,middle_name,surname,gender,age_range FROM users WHERE personal_email = ?";
    if(!$stmt_3 = mysqli_prepare($conn,$sql_query_3))
    {
        //Close Statement.
        mysqli_stmt_close($stmt_3);
        //Close Connection.
        mysqli_close($conn);
        
        die("Could not check email! Please try again later!");
    }
    else
    {
        //Bind Variables to the Prepared Statement as parameters.
        mysqli_stmt_bind_param($stmt_3,'s',$email);
        
        //Attempt to execute the Prepared Statement.
        if(!mysqli_stmt_execute($stmt_3))
        {
            //Close Statement.
            mysqli_stmt_close($stmt_3);
            //Close Connection.
            mysqli_close($conn);
            
            die("Could not check email! Please try again later!");
        }
        //mysqli_stmt_bind_result($stmt,$email);        
        
        $result_3 = mysqli_stmt_get_result($stmt_3);
        
        //if(mysqli_fetch_array($result_3, MYSQLI_NUM))
        
        //Fetch result row as an associative array. Since the result set contains only one row, we don't need to use the 'While loop'.
        //mysqli_stmt_fetch($stmt);//use this if you use 'mysqli_stmt_bind_result($stmt,$email).
        if($row = mysqli_fetch_array($result_3,MYSQLI_ASSOC)) //Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of 'mysqli_stmt_bind_result($stmt,$email)'.
        {
            //Retrieve Values.
            $id = $row["id"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
            $username = $row["username"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
            $first_name = $row["first_name"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
            $middle_name = $row["middle_name"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
            $surname = $row["surname"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
            $gender = $row["gender"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
            $age_range = $row["age_range"];//Use this if you use '$result = mysqli_stmt_get_result($stmt)' instead of //'mysqli_stmt_bind_result($stmt,$email_count)';
        
            echo "Id: $id<br>";
            echo "Username: $username<br>";
            echo "First Name: $first_name<br>";
            echo "Middle Name: $middle_name<br>";
            echo "Surname: $surname<br>";
            echo "Gender: $gender<br>";
            echo "Age Range: $age_range<br>";
            
            //Close Statement.
            mysqli_stmt_close($stmt_3);
            //Close Connection.
            mysqli_close($conn);
        }
    }
}
	//DO NOT NEED TO REDO THE HTML CODE BELOW AS WAS NOT COPY & PASTE FROM ELESEWHERE ....
?>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
	<head>
<meta name="viewport" content="width=device=width, initial-scale=1">
</head>
	<body>
	<form action="" method="post">
<label for="email_account">Email:</label>
<input type="text" name="email_account" id="email_first_part" placeholder="Email Address before '@'">
<label for="email_service"><b>@</b></label>
<input type="text" name="email_service" id="email_last_part" placeholder="Email Address after '@'">
<?php if(!empty($email_error)){echo $email_error;}?>
<br>
<button type="submit" class="login_register" name="login_register">Register/Login</button>
</body>
<html>
<?php
?>

		<script>  
			var xhr;
			 if (window.XMLHttpRequest) { // Mozilla, Safari, ...
				xhr = new XMLHttpRequest();
			} else if (window.ActiveXObject) { // IE 8 and older
				xhr = new ActiveXObject("Microsoft.XMLHTTP");
			} 
				xhr.open("POST", "PHPLibrary/selectMemberResults.php", true); 
				xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");                  
				xhr.send();
				xhr.onreadystatechange = display_data;
				var $phparray
				function display_data() {
				 if (xhr.readyState == 4) {
				  if (xhr.status == 200) {
				    //alert(xhr.responseText);	   
					$phparray = xhr.responseText;
					document.getElementById("suggestion").innerHTML = $phparray;
					//
					//
					//......................................................?
					// The above line of code is the last thing to print or 
					// to do anything that returns to the browser....
					//.......................................................?
					// All lines below do nothing............................?

					//
				  } else {
					//alert('There was a problem with the request.');
				  }
				 }
				}   
				document.write("Length of phparray Array :" + $phparray.length + "<");  
				var output = JSON.parse($phparray, function (key,val) {
					if ( typeof val === 'string' ) {
						// regular expression to remove extra white space
						if ( val.indexOf('\n') !== -1 ) {
							var re = /\s\s+/g;
							return val.replace(re, ' ');
						} else {
							return val;
						}
					}
					return val;
				} ); 
				document.write("Length of Array :" + $output.length + "<");
				for (var i=0; i < $output.length; i++)
					{
						document.getElementById("suggestion").innerHTML = $output[i].MEMBER_NAME;
					}  
		</script> 

$name = "img/".rand(1,9999999).".png";
$myFile = $name;
$fh = fopen($myFile, 'w') or die("can't open file");
$stringData = $html;
fwrite($fh, $stringData);
fclose($fh);
$file=$name;
$fst=file_get_contents($file);
$im=imagecreatefromstring($fst);
imagefilter($im, IMG_FILTER_GRAYSCALE);
imagefilter($im, IMG_FILTER_NEGATE);
//Convert to Grey Scale
for($i=0;$i<123;$i++){
for($j=0;$j<50;$j++){
$px=imagecolorat($im,$i,$j);
if($px<0x303030){
imagesetpixel($im,$i,$j,0);
}else{
imagesetpixel($im,$i,$j,0xffffff);
}
}
}
$database = unserialize(@file_get_contents("db.txt"));
if($database === false) $database = array();
// modify the database if needed
if($_SERVER['REQUEST_METHOD'] == 'POST'){
	if($_POST['submit'] == 'Add')
		$database[$_POST['ident']] = substr($_POST['letter'], 0, 1);
	if($_POST['submit'] == 'Del')
		unset($database[$_POST['ident']]);
	if($fh = @fopen('db111.txt', 'w+')){
		fwrite($fh, serialize($database));
		fclose($fh);
}
}else{
$newimage = true;
}
$width   = 130;
$height  = 40;
$captcha_gridstart   =1;
$captcha_gridspace   =2;
$letters = findletters($im, $width, $height, $captcha_gridstart, $captcha_gridspace);
$count   = count($letters);
$cellw   = ($count > 0) ? intval(100 / $count) : 0;
//dispeckle the image and GET co-ordinates of the characters of captcha image and return them. 
function findletters($image, $width, $height, $gridstart, $gridspace){
	$offsets  = array(); $o = 0;
	$atstartx = true;
	for($x = 0; $x < $width; $x++){
		$blankx = true;
		for($y = 0; $y < $height; $y++){
			if(imagecolorat($image, $x, $y) == 0){
				$blankx = false;
				break;
			}
		}
		if(!$blankx && $atstartx){
			$offsets[$o]['startx'] = $x;
			$atstartx = !$atstartx;
		}else if($blankx && !$atstartx){
			$offsets[$o]['endx']   = $x;
			$atstartx = !$atstartx;
			$o++;
		}
	}
	$count = $o;
	for($o = 0; $o < $count; $o++){
		for($y = 0; $y < $height; $y++){
			$blanky = true;
			for($x = $offsets[$o]['startx']; $x < $offsets[$o]['endx']; $x++){
				if(imagecolorat($image, $x, $y) == 0){
					$blanky = false;
					break;
				}
			}
			if(!$blanky){
				$offsets[$o]['starty'] = $y;
				break;
			}
		}
		for($y = $height-1; $y > $offsets[$o]['starty']; $y--){
			$blanky = true;
			for($x = $offsets[$o]['startx']; $x < $offsets[$o]['endx']; $x++){
				if(imagecolorat($image, $x, $y) == 0){
					$blanky = false;
					break;
				}
			}
			if(!$blanky){
				$offsets[$o]['endy'] = $y;
				break;
			}
		}
	}
	for($o = 0; $o < $count; $o++){
		$offsets[$o]['ident'] = "";
		for($x = $offsets[$o]['startx'] + $gridstart; $x < $offsets[$o]['endx']; $x += $gridspace){
			for($y = $offsets[$o]['starty'] + $gridstart; $y < $offsets[$o]['endy']; $y += $gridspace){
				$offsets[$o]['ident'] .= ((imagecolorat($image, $x, $y) == 0) ? "0" : "1");
				#echo $offsets[$o]['ident'].'<br>';
			}
		}
	}
	return $offsets;
}
$a="";
foreach($letters as $letter){
$asciiletter = $database[$letter['ident']];
if(!empty($asciiletter)) {
$a.=$asciiletter;
}
}

I need bit of help, so I am looking into a plugin created for newsletter where default is it shows ad but it has option to remove ads by checking the check box. Default is to send ads in newsletter but if you don't want to send ads through newsletter then check the box. The problem is, it seems like checkbox selected is not being picked up. Some help would be appreciated.

The custom field in wp:

'label' => 'Hide newsletter ads',
           'name' => 'hide_ads', 
          'type'  => 'checkbox',
                'instructions'      => 'Checking the checkbox will remove ads',
                'required'          => 0,
                'conditional_logic' => 0,
                'wrapper'           => array(
                    'width' => '',
                    'class' => '',
                    'id'    => '',
                ),
                'choices' => array(
                    'Hide newsletter ads' => 'Hide newsletter ads',
                ),
                'allow_custom' => 0,
                'default_value' => array(
                ),
                'layout' => 'block',
                'toggle' => 0,
                'return_format' => 'value',
                'save_custom' => 0,
               ),

This is the php code for it:

  <!doctype html>
    <html lang="en-GB">
 <head>
<meta name="viewport" content="width=device-width" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="x-apple-disable-message-reformatting">
<title><?php the_title(); ?></title>
<style>
    <?php require ABSPATH . 'path/newsletter.css'; ?>
</style>
<!--[if mso]>
<style type="text/css">
.outlook-fallback-font {
    font-family: 'Lucida Bright', 'Cambria', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
}
</style>
 <![endif]-->
 </head>

 <?php
$hide_newsletter_ads = get_field('hide_ads');
echo $hide_newsletter_ads;
?>

 <body itemscope itemtype="http://schema.org/EmailMessage">

 <div class="wrap">

    <?php
    if (!$hide_newsletter_ads) {
        include ABSPATH . 'path/ad-banner.php';
        }
    ?>
    <div class="header">
        <a href="<?php bloginfo( 'url' ); ?>">
            <img src="<?php echo get_home_url().'logo.png' ?>" alt="News" 
       />
        </a>
    </div>

    <?php
    if ( have_posts() ) :
        while ( have_posts() ) :
            the_post();
            ?>

            <?php if ( get_field( 'newsletter_summary' ) ) { ?>
                <div class="newsletter-summary"><?php the_field( 'newsletter_summary' ); ?></div>
            <?php } ?>

            <?php if ( have_rows( 'newsletter_content' ) ) : ?>

                <?php
                // Loop through the ACF blocks
                $count = 0;
                while ( have_rows( 'newsletter_content' ) ) :
                    the_row();

                    if ( get_row_layout() === 'story' ) :
                        ?>

                        <?php if ( 0 === $count ) { ?>
                            <span class="date outlook-fallback-font"><?php the_time( 'd M Y' ); ?></span>
                        <?php } ?>

                        <?php if ( get_sub_field( 'story_heading' ) ) : ?>
                            <h1><?php the_sub_field( 'story_heading' ); ?></h1>
                        <?php endif; ?>

                        <div class="content">
                            <?php the_sub_field( 'story_content' ); ?>
                        </div>

                        <?php
                    endif;

                    if ( 'post_list' === get_row_layout() ) :
                        ?>

                        <?php
                        $posts = get_sub_field( 'post_list' );
                        if ( $posts ) :
                            ?>

                        </div>
                        <div class="story-list">
                            <h2><span class="wrap"><?php the_sub_field( 'post_list_heading' ); ?></span></h2>
                            <div class="wrap-table">
                                <table width="100%" cellpadding="0" cellspacing="0" border="0">

                                    <?php
                                    // Output story cards
                                    foreach ( $posts as $i => $post ) {
                                        if ( 0 === $i % 2 ) {
                                            echo '<tr>';
                                        }

                                        $class = ( 0 === $i % 2 ) ? 'odd' : 'even';

                                        $image_src    = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), array( 640, 345 ) );
                                        $image_srcset = wp_get_attachment_image_srcset( get_post_thumbnail_id( $post->ID ) );
                                        echo sprintf(
                                            '<td class="story-cell %4$s" valign="top">
                                            <a href="%1$s" class="story-card outlook-fallback-font">
                                            <img src="%3$s" alt="" height="120" style="height: 150px; object-fit: cover;" />
                                            <span>%2$s</span>
                                            </a>
                                            </td>',
                                            esc_url( get_permalink( $post->ID ) . '?utm_source=newsletter&utm_medium=email&utm_campaign=newsletter' ), // permalink
                                            esc_html( get_the_title( $post->ID ) ), // title
                                            // esc_attr( $image_src[0] ), // image  - src
                                            esc_attr( $image_src[0] ), // image  - src
                                            esc_attr( $class ) // class
                                        );

                                        if ( 0 !== $i % 2 || count( $posts ) === ( $i + 1 ) ) {
                                            echo '</tr>';
                                        }
                                    }
                                    ?>

                                </table>
                            </div>
                        </div>
                        <div class="wrap">
                            <?php
                        endif;
                    endif;

                    if (!$hide_newsletter_ads) {

                     (0 === $count) {
                        include ABSPATH . 'path/mpu-1.php';
                    }

                    if (1 === $count) {
                        include ABSPATH . 'path/mpu-2.php';
                    }
                }

                    $count++;

                endwhile;

            endif;
            ?>

            <div class="footer">
                <table width="100%" cellpadding="0" cellspacing="0" border="0">
                    <tr>
                        <td align="left">
                            &copy;  <?php echo esc_html( date( 'Y' ) ); ?>
                        </td>
                        <td class="footer-link">
                            <a href="<?php echo get_permalink( get_page_by_path( 'privacy-policy' ) ); ?>">Privacy Policy</a> &middot;
                            <a href="%unsubscribe_url%">Unsubscribe</a>
                        </td>
                    </tr>
                </table>
            </div>

        </div>

        <?php
    endwhile;
endif;
?>