Member Login/Registration

<?PHP

/*
 *
 *      Members Registration/Login from AssembledBits
 *      2014-10-08 - 5:55AM
 *
 */

require_once("class.phpmailer.php");
require_once("formvalidator.php");

class Members
{
    var $admin_email;
    var $sitename;
    var $from_address;

    var $db_username;
    var $db_password;
    var $db_name;
    var $db_table;
    var $db_connection;

    var $rand_key;

    var $error_message;

/*  ==========================================================================
    Initialize database variables
    ========================================================================== */
    function InitDB($host,$username,$password,$database,$table)
    {
        $this->db_host      = $host;
        $this->db_username  = $username;
        $this->db_password  = $password;
        $this->db_name      = $database;
        $this->db_table     = $table;
    }

/*  ==========================================================================
    Set the admin contact e-mail address
    ========================================================================== */
    function SetAdminEmail($email)
    {
        $this->admin_email = $email;
    }

/*  ==========================================================================
    Set Website Name
    ========================================================================== */
    function SetWebsiteName($sitename)
    {
        $this->sitename = $sitename;
    }

/*  ==========================================================================
    Set Random Key Generation
    ========================================================================== */
    function SetRandomKey($key)
    {
        $this->rand_key = $key;
    }

    /*
     *     _______ _______ _______ ______ _______ _______ _______ _______ _______
     *    |    ___|   |   |    |  |      |_     _|_     _|       |    |  |     __|
     *    |    ___|   |   |       |   ---| |   |  _|   |_|   -   |       |__     |
     *    |___|   |_______|__|____|______| |___| |_______|_______|__|____|_______|
     *
     */

/*  ==========================================================================
    Register User

    <?php
        if(isset($_POST['submitted']))
        {
           if($members->RegisterUser())
           {
                $members->RedirectToURL("thank-you.html");
           }
        }
    ?>

    <form>
        <input type='hidden' name='submitted' id='submitted' value='1'/>
        <input type='text'  class='spmhidip' name='<?php echo $members->GetSpamTrapInputName(); ?>' />

        <input type='text' name='user_name' id='user_name' value='<?php echo $members->SafeDisplay('user_name') ?>' maxlength="50" />
        <input type='text' name='user_email' id='user_email' value='<?php echo $members->SafeDisplay('user_email') ?>' maxlength="50" />
        <input type='password' name='user_password' id='password' maxlength="50" />
    </form>

    ========================================================================== */
    function RegisterUser()
    {
        if(!isset($_POST['submitted']))
        {
           return false;
        }

        $formvars = array();

        if(!$this->ValidateRegistrationSubmission())
        {
            return false;
        }

        $this->CollectRegistrationSubmission($formvars);

        if(!$this->SaveToDatabase($formvars))
        {
            return false;
        }

        if(!$this->SendUserConfirmationEmail($formvars))
        {
            return false;
        }

        $this->SendAdminIntimationEmail($formvars);

        return true;
    }

/*  ==========================================================================
    Confirm User

    <label for='code'>Confirmation Code:*
        <input type='text' name='code' id='code' maxlength="50" />
    </label>

    <?php
        if(isset($_GET['code']))
        {
           if($members->ConfirmUser())
           {
                $members->RedirectToURL("thank-you-regd.html");
           }
        }
    ?>

    ========================================================================== */
    function ConfirmUser()
    {
        if(empty($_GET['code'])||strlen($_GET['code'])<=10)
        {
            $this->HandleError("Please provide the confirm code");
            return false;
        }
        $user_rec = array();
        if(!$this->UpdateDBRecForConfirmation($user_rec))
        {
            return false;
        }

        $this->SendUserWelcomeEmail($user_rec);

        $this->SendAdminIntimationOnRegComplete($user_rec);

        return true;
    }

/*  ==========================================================================
    Login

    <input type='hidden' name='submitted' id='submitted' value='1'/>

    <?php
        if(isset($_POST['submitted']))
        {
           if($members->Login())
           {
                $members->RedirectToURL("login-home.php");
           }
        }
    ?>

    ========================================================================== */
    function Login()
    {
        if(empty($_POST['user_email']))
        {
            $this->HandleError("Email is empty!");
            return false;
        }

        if(empty($_POST['user_password']))
        {
            $this->HandleError("Password is empty!");
            return false;
        }

        $email = trim($_POST['user_email']);
        $password = trim($_POST['user_password']);

        if(!isset($_SESSION)){ session_start(); }
        if(!$this->CheckLoginInDB($email,$password))
        {
            return false;
        }

        $_SESSION[$this->GetLoginSessionVar()] = $email;

        return true;
    }

/*  ==========================================================================
    Check Login

    !! Put at the top of any access controlled document

    <?PHP
        require_once("membersite_config.php");

        if(!$members->CheckLogin())
        {
            $members->RedirectToURL("login.php");
            exit;
        }
    ?>

    ========================================================================== */
    function CheckLogin()
    {
        if(!isset($_SESSION)){ session_start(); }

        $sessionvar = $this->GetLoginSessionVar();

        if(empty($_SESSION[$sessionvar]))
        {
        return false;
        }
        return true;
    }

/*  ==========================================================================
    Log Out

    <?php
        $members->LogOut();
    ?>

    ========================================================================== */
    function LogOut()
    {
        session_start();

        $sessionvar = $this->GetLoginSessionVar();

        $_SESSION[$sessionvar]=NULL;

        unset($_SESSION[$sessionvar]);
    }

/*  ==========================================================================
    User Fullname (SESSION)

    Logged in as: <?= $members->UserFullName() ?>

    ========================================================================== */
    function UserFullName()
    {
        return isset($_SESSION['user_name'])?$_SESSION['user_name']:'';
    }

/*  ==========================================================================
    User Email (SESSION)

    <input type="text" id="user_email" name="user_email" value="<?= $members->UserEmail() ?>" />

    ========================================================================== */
    function UserEmail()
    {
        return isset($_SESSION['user_email'])?$_SESSION['user_email']:'';
    }

/*  ==========================================================================
    Checks the database for the submitted email and if matches, will send an
    email for the password reset url

    <?php
        $emailsent = false;

        if(isset($_POST['submitted']))
        {
           if($members->EmailResetPasswordLink())
           {
                $members->RedirectToURL("reset-pwd-link-sent.html");
                exit;
           }
        }
    ?>

*/
    function EmailResetPasswordLink()
    {
        if(empty($_POST['user_email']))
        {
            $this->HandleError("Email is empty!");
            return false;
        }
        $user_rec = array();
        if(false === $this->GetUserFromEmail($_POST['user_email'], $user_rec))
        {
            return false;
        }
        if(false === $this->SendResetPasswordLink($user_rec))
        {
            return false;
        }
        return true;
    }

/*  ==========================================================================
    Reset Password

    <?php
        $success = false;
        if($members->ResetPassword())
        {
            $success=true;
        }
    ?>

    <?php
        if($success){
        ?>
            <h2>Password is Reset Successfully</h2>
            <p>Your new password is sent to your email address.</p>
        <?php
        }else{
        ?>
            <h2>Error</h2>
            <span class='error'><?php echo $members->GetErrorMessage(); ?></span>
        <?php
        }
    ?>

    ========================================================================== */
    function ResetPassword()
    {
        if(empty($_GET['user_email']))
        {
            $this->HandleError("Email is empty!");
            return false;
        }
        if(empty($_GET['code']))
        {
            $this->HandleError("reset code is empty!");
            return false;
        }
        $email = trim($_GET['user_email']);
        $code = trim($_GET['code']);

        if($this->GetResetPasswordCode($email) != $code)
        {
            $this->HandleError("Bad reset code!");
            return false;
        }

        $user_rec = array();
        if(!$this->GetUserFromEmail($email,$user_rec))
        {
            return false;
        }

        $new_password = $this->ResetUserPasswordInDB($user_rec);
        if(false === $new_password || empty($new_password))
        {
            $this->HandleError("Error updating new password");
            return false;
        }

        if(false == $this->SendNewPassword($user_rec,$new_password))
        {
            $this->HandleError("Error sending new password");
            return false;
        }
        return true;
    }

/*  ==========================================================================
    Change Password

    checks if form was submitted, if successful, will redirect

    <input type='hidden' name='submitted' id='submitted' value='1'/>
    <?php
        if(isset($_POST['submitted']))
        {
           if($members->ChangePassword())
           {
                $members->RedirectToURL("changed-pwd.html");
           }
        }
    ?>

    ========================================================================== */
    function ChangePassword()
    {
        if(!$this->CheckLogin())
        {
            $this->HandleError("Not logged in!");
            return false;
        }

        if(empty($_POST['oldpwd']))
        {
            $this->HandleError("Old password is empty!");
            return false;
        }
        if(empty($_POST['newpwd']))
        {
            $this->HandleError("New password is empty!");
            return false;
        }

        $user_rec = array();
        if(!$this->GetUserFromEmail($this->UserEmail(),$user_rec))
        {
            return false;
        }

        $pwd = trim($_POST['oldpwd']);

        $salt = $user_rec['user_salt'];
        $hash = $this->checkhashSSHA($salt, $pwd);

        if($user_rec['user_password'] != $hash)
        {
            $this->HandleError("The old password does not match!");
            return false;
        }
        $newpwd = trim($_POST['newpwd']);

        if(!$this->ChangePasswordInDB($user_rec, $newpwd))
        {
            return false;
        }
        return true;
    }

    /*
     *     ______ _______ ______ _____   _______ ______      _______ _______ _____   ______ _______ ______ _______
     *    |   __ \   |   |   __ \     |_|_     _|      |    |   |   |    ___|     |_|   __ \    ___|   __ \     __|
     *    |    __/   |   |   __ <       |_|   |_|   ---|    |       |    ___|       |    __/    ___|      <__     |
     *    |___|  |_______|______/_______|_______|______|    |___|___|_______|_______|___|  |_______|___|__|_______|
     *
     */

/*  ==========================================================================
    Get Self
    ========================================================================== */
    function GetSelfScript()
    {
        return htmlentities($_SERVER['PHP_SELF']);
    }

/*  ==========================================================================
    Safe Display
    ========================================================================== */
    function SafeDisplay($value_name)
    {
        if(empty($_POST[$value_name]))
        {
            return'';
        }
        return htmlentities($_POST[$value_name]);
    }

/*  ==========================================================================
    Redirect To URL
    ========================================================================== */
    function RedirectToURL($url)
    {
        header("Location: $url");
        exit;
    }

/*  ==========================================================================
    Spam Trap

    <input type='text'  class='spmhidip' name='<?php echo $members->GetSpamTrapInputName(); ?>' />

    ========================================================================== */
    function GetSpamTrapInputName()
    {
        return 'sp'.md5('KHGdnbvsgst'.$this->rand_key);
    }

/*  ==========================================================================
    Error Message

    Displays error on script page

    <div>
        <span class='error'>
            <?php echo $members->GetErrorMessage(); ?>
        </span>
    </div>

    ========================================================================== */
    function GetErrorMessage()
    {
        if(empty($this->error_message))
        {
            return '';
        }
        $errormsg = nl2br(htmlentities($this->error_message));
        return $errormsg;
    }

    /*
     *     ______ ______ _______ ___ ___ _______ _______ _______      _______ _______ _____   ______ _______ ______ _______
     *    |   __ \   __ \_     _|   |   |   _   |_     _|    ___|    |   |   |    ___|     |_|   __ \    ___|   __ \     __|
     *    |    __/      <_|   |_|   |   |       | |   | |    ___|    |       |    ___|       |    __/    ___|      <__     |
     *    |___|  |___|__|_______|\_____/|___|___| |___| |_______|    |___|___|_______|_______|___|  |_______|___|__|_______|
     *
     */

/*  ==========================================================================
    Error Handler
    ========================================================================== */
    function HandleError($err, $sqlerr = null)
    {
        $this->error_message .= $err."\r\n";
        if($sqlerr) {
            $this->error_message .= $sqlerr."\r\n";
        }
    }

/*  ==========================================================================
    Handle DB Errors
    ========================================================================== */
    function HandleDBError($err, $sqlerr = null)
    {
        $this->HandleError($err, $sqlerr);
    }

/*  ==========================================================================
    Get 'From' Address
    ========================================================================== */
    function GetFromAddress()
    {
        if(!empty($this->from_address))
        {
            return $this->from_address;
        }

        $host = $_SERVER['SERVER_NAME'];

        $from ="info@$host";
        return $from;
    }

/*  ==========================================================================
    Get Login Session
    ========================================================================== */
    function GetLoginSessionVar()
    {
        $retvar = md5($this->rand_key);
        $retvar = 'usr_'.substr($retvar,0,10);
        return $retvar;
    }

/*  ==========================================================================
    Check User Login in DB
    ========================================================================== */
    function CheckLoginInDB($email,$password)
    {
        if(!$this->DBLogin())
        {
            $this->HandleError("Database login failed!");
            return false;
        }

        $check_db_for_email_stmt = $this->db->prepare("SELECT * FROM $this->db_table WHERE user_email = :user_email");
        $check_db_for_email_stmt->execute(array('user_email' => $email));
        $result = $check_db_for_email_stmt->fetchAll();

        if($result) {
            $salt = $result[0]['salt'];
            $encrypted_password = $result[0]['password'];
            $hash = $this->checkhashSSHA($salt, $password);
        }

        $user_login_stmt = $this->db->prepare("Select user_name, user_email from $this->db_table where user_email = :user_email and user_password = :hash and user_confirmcode='y'");
        $user_login_stmt->execute(array('user_email' => $email, 'user_password' => $hash));
        $result = $user_login_stmt->fetchAll();

        if(!$result)
        {
            $this->HandleError("Error logging in. The username or password does not match");
            return false;
        }

        $_SESSION['user_name']  = $result[0]['user_name'];
        $_SESSION['user_email'] = $result[0]['user_email'];

        return true;
    }

/*  ==========================================================================
    Check Hash
    ========================================================================== */
    public function checkhashSSHA($salt, $password)
    {
        $hash = base64_encode(sha1($password . $salt, true) . $salt);
        return $hash;
    }

/*  ==========================================================================
    Update DB on Registration confirmation
    ========================================================================== */
    function UpdateDBRecForConfirmation(&$user_rec)
    {
        if(!$this->DBLogin())
        {
            $this->HandleError("Database login failed!");
            return false;
        }

        $confirmcode = $_GET['code'];

        $check_confirmation_code_stmt = $this->db->prepare("Select user_name, user_email from $this->db_table where user_confirmcode = :user_confirmcode");
        $check_confirmation_code_stmt->execute(array('user_confirmcode' => $confirmcode));

        $result = $check_confirmation_code_stmt->fetchAll();

        if(!$result) {
            $this->HandleError("Wrong confirm code");
            return false;
        }

        $row = $result[0];
        $user_rec['user_name'] = $row['user_name'];
        $user_rec['user_email'] = $row['user_email'];

        try {
            $update_confirmation_code_stmt = $this->db->prepare("Update $this->db_table Set user_confirmcode = 'y' Where user_confirmcode = :user_confirmcode");
            $update_confirmation_code_stmt->execute(array('user_confirmcode' => $confirmcode));
        } catch(PDOException $e) {
            $this->HandleDBError("Error inserting data to the table", $e->getMessage());
            return false;
        }
        return true;
    }

/*  ==========================================================================
    Reset user password in DB
    ========================================================================== */
    function ResetUserPasswordInDB($user_rec)
    {
        $new_password = substr(md5(uniqid()),0,10);

        if(false == $this->ChangePasswordInDB($user_rec,$new_password))
        {
            return false;
        }
        return $new_password;
    }

/*  ==========================================================================
    Change password in DB
    ========================================================================== */
    function ChangePasswordInDB($user_rec, $newpwd)
    {
        $hash = $this->hashSSHA($newpwd);

        $new_password = $hash["encrypted"];

        $salt = $hash["salt"];

        try {
            $change_password_in_db = $this->db->prepare("Update $this->db_table Set user_password = :user_password, user_salt = :user_salt Where user_id = :user_id");
            $change_password_in_db->execute(array('user_password' => $new_password, 'user_salt' => $salt, 'user_id' => $user_rec['user_id']));
        } catch(PDOException $e) {
            $this->HandleDBError("Error updating the password", $e->getMessage());
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function GetUserFromEmail($email,&$user_rec)
    {
        if(!$this->DBLogin())
        {
            $this->HandleError("Database login failed!");
            return false;
        }

        $get_user_from_email_stmt = $this->db->prepare("Select * from $this->db_table where user_email = :user_email");
        $get_user_from_email_stmt->execute(array(':user_email' => $email));
        $result = $get_user_from_email_stmt->fetchAll();

        if(!$result)
        {
            $this->HandleError("There is no user with email: $email");
            return false;
        }
        $user_rec = $result[0];

        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function SendUserWelcomeEmail(&$user_rec)
    {
        $mailer = new PHPMailer();

        $mailer->CharSet = 'utf-8';

        $mailer->AddAddress($user_rec['user_email'],$user_rec['user_name']);

        $mailer->Subject = "Welcome to ".$this->sitename;

        $mailer->From = $this->GetFromAddress();

        $mailer->Body ="Hello ".$user_rec['user_name']."\r\n\r\n".
        "Welcome! Your registration  with ".$this->sitename." is completed.\r\n".
        "\r\n".
        "Regards,\r\n".
        "Webmaster\r\n".
        $this->sitename;

        if(!$mailer->Send())
        {
            $this->HandleError("Failed sending user welcome email.");
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function SendAdminIntimationOnRegComplete(&$user_rec)
    {
        if(empty($this->admin_email))
        {
            return false;
        }
        $mailer = new PHPMailer();

        $mailer->CharSet = 'utf-8';

        $mailer->AddAddress($this->admin_email);

        $mailer->Subject = "Registration Completed: ".$user_rec['user_name'];

        $mailer->From = $this->GetFromAddress();

        $mailer->Body ="A new user registered at ".$this->sitename."\r\n".
        "Name: ".$user_rec['user_name']."\r\n".
        "Email address: ".$user_rec['user_email']."\r\n";

        if(!$mailer->Send())
        {
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function GetResetPasswordCode($email)
    {
       return substr(md5($email.$this->sitename.$this->rand_key),0,10);
    }

/*  ==========================================================================

    ========================================================================== */
    function SendResetPasswordLink($user_rec)
    {
        $email = $user_rec['user_email'];

        $mailer = new PHPMailer();

        $mailer->CharSet = 'utf-8';

        $mailer->AddAddress($email,$user_rec['user_name']);

        $mailer->Subject = "Your reset password request at ".$this->sitename;

        $mailer->From = $this->GetFromAddress();

        $link = $this->GetAbsoluteURLFolder().
                '/resetpwd.php?email='.
                urlencode($email).'&code='.
                urlencode($this->GetResetPasswordCode($email));

        $mailer->Body ="Hello ".$user_rec['user_name']."\r\n\r\n".
        "There was a request to reset your password at ".$this->sitename."\r\n".
        "Please click the link below to complete the request: \r\n".$link."\r\n".
        "Regards,\r\n".
        "Webmaster\r\n".
        $this->sitename;

        if(!$mailer->Send())
        {
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function SendNewPassword($user_rec, $new_password)
    {
        $email = $user_rec['user_email'];

        $mailer = new PHPMailer();

        $mailer->CharSet = 'utf-8';

        $mailer->AddAddress($email,$user_rec['user_name']);

        $mailer->Subject = "Your new password for ".$this->sitename;

        $mailer->From = $this->GetFromAddress();

        $mailer->Body ="Hello ".$user_rec['user_name']."\r\n\r\n".
        "Your password is reset successfully. ".
        "Here is your updated login:\r\n".
        "username:".$user_rec['user_name']."\r\n".
        "password:$new_password\r\n".
        "\r\n".
        "Login here: ".$this->GetAbsoluteURLFolder()."/login.php\r\n".
        "\r\n".
        "Regards,\r\n".
        "Webmaster\r\n".
        $this->sitename;

        if(!$mailer->Send())
        {
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function ValidateRegistrationSubmission()
    {
        //This is a hidden input field. Humans won't fill this field.
        if(!empty($_POST[$this->GetSpamTrapInputName()]) )
        {
            //The proper error is not given intentionally
            $this->HandleError("Automated submission prevention: case 2 failed");
            return false;
        }

        $validator = new FormValidator();
        $validator->addValidation("user_name","req","Please fill in Name");
        $validator->addValidation("user_email","email","The input for Email should be a valid email value");
        $validator->addValidation("user_email","req","Please fill in Email");
        $validator->addValidation("user_password","req","Please fill in Password");


        if(!$validator->ValidateForm())
        {

            $error='';
            $error_hash = $validator->GetErrors();
            foreach($error_hash as $inpname => $inp_err)
            {
                $error .= $inpname.':'.$inp_err."\n";
            }
            $this->HandleError($error);
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function CollectRegistrationSubmission(&$formvars)
    {
        $formvars['user_name'] = $this->Sanitize($_POST['user_name']);
        $formvars['user_email'] = $this->Sanitize($_POST['user_email']);
        $formvars['user_phone'] = $this->Sanitize($_POST['user_phone']);
        $formvars['user_password'] = $this->Sanitize($_POST['user_password']);

        $confirmcode = $this->MakeConfirmationMd5($formvars['user_email']);
        $formvars['user_confirmcode'] = $confirmcode;
    }

/*  ==========================================================================

    ========================================================================== */
    function SendUserConfirmationEmail(&$formvars)
    {
        $mailer = new PHPMailer();

        $mailer->CharSet = 'utf-8';

        $mailer->AddAddress($formvars['user_email'],$formvars['user_name']);

        $mailer->Subject = "Your registration with ".$this->sitename;

        $mailer->From = $this->GetFromAddress();

        $confirmcode = $formvars['user_confirmcode'];

        $confirm_url = $this->GetAbsoluteURLFolder().'/confirmreg.php?code='.$confirmcode;

        $mailer->Body ="Hello ".$formvars['user_name']."\r\n\r\n".
        "Thanks for your registration with ".$this->sitename."\r\n".
        "Please click the link below to confirm your registration.\r\n".
        "$confirm_url\r\n".
        "\r\n".
        "Regards,\r\n".
        "Webmaster\r\n".
        $this->sitename;

        if(!$mailer->Send())
        {
            $this->HandleError("Failed sending registration confirmation email.");
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function GetAbsoluteURLFolder()
    {
        $scriptFolder = (isset($_SERVER['HTTPS']) && ($_SERVER['HTTPS'] == 'on')) ? 'https://' : 'http://';

        $urldir ='';
        $pos = strrpos($_SERVER['REQUEST_URI'],'/');
        if(false !==$pos)
        {
            $urldir = substr($_SERVER['REQUEST_URI'],0,$pos);
        }

        $scriptFolder .= $_SERVER['HTTP_HOST'].$urldir;

        return $scriptFolder;
    }

/*  ==========================================================================

    ========================================================================== */
    function SendAdminIntimationEmail(&$formvars)
    {
        if(empty($this->admin_email))
        {
            return false;
        }
        $mailer = new PHPMailer();

        $mailer->CharSet = 'utf-8';

        $mailer->AddAddress($this->admin_email);

        $mailer->Subject = "New registration: ".$formvars['user_name'];

        $mailer->From = $this->GetFromAddress();

        $mailer->Body ="A new user registered at ".$this->sitename."\r\n".
        "Name: ".$formvars['user_name']."\r\n".
        "Email address: ".$formvars['user_email']."\r\n".
        "Phone number: ".$formvars['user_phone'];

        if(!$mailer->Send())
        {
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function SaveToDatabase(&$formvars)
    {
        if(!$this->DBLogin())
        {
            $this->HandleError("Database login failed!");
            return false;
        }
        if(!$this->Ensuretable())
        {
            return false;
        }
        if(!$this->IsFieldUnique($formvars,'user_email'))
        {
            $this->HandleError("This email is already registered");
            return false;
        }
        if(!$this->InsertIntoDB($formvars))
        {
            $this->HandleError("Inserting to Database failed!");
            return false;
        }
        return true;
    }
/*  ==========================================================================

    ========================================================================== */
    function IsFieldUnique($formvars,$fieldname)
    {
        $fieldname = $this->db->quote($fieldname);

        $is_field_unique_stmt = $this->db->prepare("select user_email from $this->db_table where $fieldname = :fieldname");
        $is_field_unique_stmt->execute(array('fieldname' => $formvars[$fieldname]));
        $result = $is_field_unique_stmt->fetchAll();

        // if there is a result (field is not unique), return false
        if($result)
        {
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function DBLogin()
    {
        try {
            $this->db = new PDO("mysql:dbname={$this->db_name};host={$this->db_host};charset=utf8", $this->db_username, $this->db_password, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
        } catch(PDOException $e) {
            $this->HandleDBError("Database Login failed! Please make sure that the DB login credentials provided are correct", $e->getMessage());
            return false;
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function Ensuretable()
    {
        try {
            $ensure_table_stmt = $this->db->query("select 1 from $this->db_table");
            $result = $ensure_table_stmt->fetchAll();
        } catch (PDOException $e) {
            // We got an exception == table not found
            $result = false;
        }

        // if result is false user table is created
        if(!$result) {
            return $this->CreateTable();
        }
        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function CreateTable()
    {
        $create_table_stmt =    "Create Table $this->db_table (".
                                "user_id INT NOT NULL AUTO_INCREMENT ,".
                                "user_name VARCHAR( 128 ) NOT NULL ,".
                                "user_email VARCHAR( 64 ) NOT NULL ,".
                                "user_phone VARCHAR( 16 ) ,".
                                "user_salt VARCHAR( 50 ) NOT NULL ,".
                                "user_stripe_id VARCHAR( 64 ) ,".
                                "user_password VARCHAR( 80 ) NOT NULL ,".
                                "user_confirmcode VARCHAR(32) ,".
                                "PRIMARY KEY ( user_id )".
                                ")";

        try {
            $this->db->query($create_table_stmt);
        } catch(PDOException $e) {
            $this->HandleDBError("Error creating the table", $e->getMessage());
            return false;
        }

        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function InsertIntoDB(&$formvars)
    {
        $hash = $this->hashSSHA($formvars['user_password']);

        $encrypted_password = $hash["encrypted"];

        $salt = $hash["salt"];

        try {
            $insert_user_stmt = $this->db->prepare("INSERT INTO $this->db_table
                                                    (user_name, user_email, user_phone, user_password, user_salt, user_stripe_id, user_confirmcode)
                                                    VALUES
                                                    (:user_name,:user_email,:user_phone,:user_password,:user_salt,:user_stripe_id,:user_confirmcode)");

            $insert_user_stmt->execute( array(  'user_name' => $formvars['user_name'],
                                                'user_email' => $formvars['user_email'],
                                                'user_phone' => $formvars['user_phone'],
                                                'user_password' => $encrypted_password,
                                                'user_salt' => $salt,
                                                'user_stripe_id' => $formvars['user_stripe_id'],
                                                'user_confirmcode' => $formvars['user_confirmcode']));
        } catch(PDOException $e) {
            $this->HandleDBError("Error inserting data to the table", $e->getMessage());
            return false;
        }

        return true;
    }

/*  ==========================================================================

    ========================================================================== */
    function hashSSHA($password)
    {
        $salt = sha1(rand());
        $salt = substr($salt, 0, 10);
        $encrypted = base64_encode(sha1($password . $salt, true) . $salt);
        $hash = array("salt" => $salt, "encrypted" => $encrypted);
        return $hash;
    }

/*  ==========================================================================

    ========================================================================== */
    function MakeConfirmationMd5($email)
    {
        $randno1 = rand();
        $randno2 = rand();
        return md5($email.$this->rand_key.$randno1.''.$randno2);
    }

/*  ==========================================================================

    Sanitize() function removes any potential threat from the
    data submitted. Prevents email injections or any other hacker attempts.
    if $remove_nl is true, newline chracters are removed from the input.

    ========================================================================== */
    function Sanitize($str,$remove_nl=true)
    {
        if($remove_nl)
        {
            $injections = array('/(\n+)/i',
                '/(\r+)/i',
                '/(\t+)/i',
                '/(%0A+)/i',
                '/(%0D+)/i',
                '/(%08+)/i',
                '/(%09+)/i'
            );
            $str = preg_replace($injections,'',$str);
        }

        return $str;
    }

} // end of Members() class