Discussion – Lesson 6 - NOO-CMS - Article editor in PHP

help me out i cant fix the error
"
Fatal error: Call to a member function prepare() on null in C:\xampp\htdoc­s\PhpProject1\dbb­.php on line 66"

dbb.php

<?php

/*
 *       _____ _____ _____                _       _
 *      |_   _/  __ \_   _|              (_)     | |
 *        | | | /  \/ | |  ___  ___   ___ _  __ _| |
 *        | | ||      | | / __|/ _ \ / __| |/ _` | |
 *       _| |_| \__/\ | |_\__ \ (_) | (__| | (_| | |
 *      |_____\_____/ |_(_)___/\___/ \___|_|\__,_|_|
 *                   ___
 *                  |  _|___ ___ ___
 *                  |  _|  _| -_| -_|  LICENCE
 *                  |_| |_| |___|___|
 *
 * IT NEWS  <>  PROGRAMMING  <>  HW & SW  <>  COMMUNITY
 *
 * This source code is part of online courses at IT social
 * network WWW.ICT.SOCIAL
 *
 * Feel free to use it for whatever you want, modify it and share it but
 * don't forget to keep this link in code.
 *
 * For more information visit http://www.ict.social/licences
 *
 * A simple database wrapper over the PDO class
 */
class Db
{
        /**
         * @var PDO A database connection
         */
        private static $connection;

        /**
         * @var array The default driver settings
         */
        private static $options = array(
                PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING,
                PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
                PDO::ATTR_EMULATE_PREPARES => false,
        );

        /**
         * Connects to the database using given credentials
         * @param string $host Host name
         * @param string $database Database name
         * @param string $user Username
         * @param string $password Password
         */
        public static function connect($host, $database, $user)
        {
                if (!isset(self::$connection)) {
                        $dsn = "mysql:host=$host;dbname=$database";
                        self::$connection = new PDO($dsn, $user,  self::$options);
                }
        }

        /**
         * Executes a query and returns the PDO statement
         * @param array $params An array where the first item represents the query and the other items are its parameters.
         * @return \PDOStatement PDO statement
         */
        private static function executeStatement($params)
        {
                $query = array_shift($params);
                $statement = self::$connection->prepare($query);
                $statement->execute($params);
                return $statement;
        }

        /**
         * Executes a query and returns the number of affected rows.
         * Any other parameters will be passed into the query.
         * @param string $query The query
         * @return int The number of affected rows
         */
        public static function query($query) {
                $statement = self::executeStatement(func_get_args());
                return $statement->rowCount();
        }

        /**
         * Executes a query and returns the value of the first column of the first row.
         * Any other parameters will be passed into the query.
         * @param string $query The query
         * @return mixed The value of the first column of the first row
         */
        public static function querySingle($query) {
                $statement = self::executeStatement(func_get_args());
                $data = $statement->fetch();
                return $data[0];
        }

        /**
         * Executes a query and returns the first row of the result.
         * Any other parameters will be passed into the query.
         * @param string $query The query
         * @return mixed An associative array representing the row or false in no data returned
         */
        public static function queryOne($query) {
                $statement = self::executeStatement(func_get_args());
                return $statement->fetch(PDO::FETCH_ASSOC);
        }

        /**
         * Executes a query and returns all resulting rows as an array of associative arrays.
         * Any other parameters will be passed into the query.
         * @param string $query The query
         * @return mixed An array of associative arrays or false in no data returned
         */
        public static function queryAll($query) {
                $statement = self::executeStatement(func_get_args());
                return $statement->fetchAll(PDO::FETCH_ASSOC);
        }

        /**
         * Inserts data from an associative array into the database as a new row
         * @param string $table The table name
         * @param array $data The associative array where keys preresent columns and values their values
         * @return int The number of affected rows
         */
        public static function insert($table, $data) {
                $keys = array_keys($data);
                self::checkIdentifiers(array($table) + $keys);
                $query = "
                        INSERT INTO `$table` (`" . implode('`, `', $keys) . "`)
                        VALUES (" . str_repeat('?,', count($data) - 1) . "?)
                ";
                $params = array_merge(array($query), array_values($data));
                $statement = self::executeStatement($params);
                return $statement->rowCount();
        }

        /**
         * Executes an update and passes data from an associative array to it
         * @param string $table The table name
         * @param array $data The associative array where keys preresent columns and values their values
         * @param string $condition A string containing the condition (WHERE)
         * @return mixed The number of affected rows
         */
        public static function update($table, $data, $condition) {
                $keys = array_keys($data);
                self::checkIdentifiers(array($table) + $keys);
                $query = "
                        UPDATE `$table` SET `".
                        implode('` = ?, `', array_keys($data)) . "` = ?
                        $condition
                ";
                $params = array_merge(array($query), array_values($data), array_slice(func_get_args(), 3));
                $statement = self::executeStatement($params);
                return $statement->rowCount();
        }

        /**
         * Returns the ID of the last inserted row
         * @return mixed The ID of the last inserted row
         */
        public static function getLastId()
        {
                return self::$connection->lastInsertId();
        }

        /**
         * Quotes a given string to protect it against the SQL injection
         * @param string $string The string
         * @return mixed The quoted string
         */
        public static function quote($string)
        {
                return self::$connection->quote($string);
        }

        /**
         * Checks whether given identifiers don't contain dangerous characters
         * @param array $identifiers The identifiers
         * @throws \Exception
         */
        private static function checkIdentifiers($identifiers)
        {
                foreach ($identifiers as $identifier)
                {
                        if (!preg_match('/^[a-zA-Z0-9\_\-]+$/u', $identifier))
                                throw new Exception('Dangerous identifier in SQL query');
                }
        }
}

editor.php code

<?php
session_start();

require('Dbb.php');

$article = array(
        'article_id' => '',
        'title' => '',
        'content' => '',
        'description' => '',
);
if ($_POST)
{
        if (!$_POST['article_id'])
        {
                Db::query('
                        INSERT INTO article (title, content, description)
                        VALUES (?, ?, ?, ?)
                ', $_POST['title'], $_POST['content'], $_POST['description']);
        }
        else
        {
                Db::query('
                        UPDATE article
                        SET title=?, content=?,  description=?
                        WHERE article_id=?
                ', $_POST['title'], $_POST['content'], $_POST['description'], $_POST['article_id']);
        }
        header('Location: index.php');
        exit();
}
else
?>
<!DOCTYPE html>
<html lang="en">
<head>
        <meta charset="utf-8" />
        <link rel="stylesheet" href="style.css" type="text/css" />
        <title>Article editor</title>
</head>

<body>
    <header>
                        <div id="logo"><h1></h1></div>
                <nav>
                        <ul>
                            <li><a href="home.php">Home</a></li>
                                <li><a href="about.php">About us</a></li>
                                <li><a href="members.php">members</a></li>
                                <li><a href="contact.php">Contact</a></li>


                        </ul>
                </nav>
</header>
        <article>
                <div id="centerer">
                        <header>
                                <h1>Article editor</h1>
                        </header>
                        <section>

                                <form method="post">
                                        <input type="hidden" name="article_id" value="<?= htmlspecialchars($article['article_id']) ?>" /><br />
                                        title<br />
                                        <input type="text" name="title" value="<?= htmlspecialchars($article['title']) ?>" /><br />
                                        Description<br />
                                        <input type="text" name="description" value="<?= htmlspecialchars($article['description']) ?>" /><br />
                                        <textarea name="content"><?= htmlspecialchars($article['content']) ?></textarea>
                                        <input type="submit" value="Submit" />
                                </form>
                        </section>
                        <div class="clear"></div>
                </div>
        </article>
        <script type="text/javascript" src="//cdn.tinymce.com/4/tinymce.min.js"></script>
        <script type="text/javascript">
                tinymce.init({
                        selector: "textarea[name=content]",
                        plugins: [
                                "advlist autolink lists link image charmap print preview anchor",
                                "searchreplace visualblocks code fullscreen",
                                "insertdatetime media table contextmenu paste"
                        ],
                        toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image",
                        entities: "160,nbsp",
                        entity_encoding: "named",
                        entity_encoding: "raw"
                });
        </script>
     <footer>
                        Made by &copy;<a href="http://www.facebook.com/lawnj">lawrence</a>
                </footer>
</body>
</html>

You have 4 question marks in INSERT and only 3 variables. So remove 1 question mark.
Btw. you can use insert() instead query(). Check the function.

more help please
"Warning: array_keys() expects parameter 1 to be array, string given in C:\xampp\htdoc­s\PhpProject1\dbb­.php on line 123

Fatal error: Unsupported operand types in C:\xampp\htdoc­s\PhpProject1\dbb­.php on line 124"
dbb.php

<?php

/*
 *       _____ _____ _____                _       _
 *      |_   _/  __ \_   _|              (_)     | |
 *        | | | /  \/ | |  ___  ___   ___ _  __ _| |
 *        | | ||      | | / __|/ _ \ / __| |/ _` | |
 *       _| |_| \__/\ | |_\__ \ (_) | (__| | (_| | |
 *      |_____\_____/ |_(_)___/\___/ \___|_|\__,_|_|
 *                   ___
 *                  |  _|___ ___ ___
 *                  |  _|  _| -_| -_|  LICENCE
 *                  |_| |_| |___|___|
 *
 * IT NEWS  <>  PROGRAMMING  <>  HW & SW  <>  COMMUNITY
 *
 * This source code is part of online courses at IT social
 * network WWW.ICT.SOCIAL
 *
 * Feel free to use it for whatever you want, modify it and share it but
 * don't forget to keep this link in code.
 *
 * For more information visit http://www.ict.social/licences
 *
 * A simple database wrapper over the PDO class
 */
class Db
{
        /**
         * @var PDO A database connection
         */
        private static $connection;

        /**
         * @var array The default driver settings
         */
        private static $options = array(
                PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING,
                PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
                PDO::ATTR_EMULATE_PREPARES => false,
        );

        /**
         * Connects to the database using given credentials
         * @param string $host Host name
         * @param string $database Database name
         * @param string $user Username
         * @param string $password Password
         */
        public static function connect($host, $database, $user)
        {
                if (!isset(self::$connection)) {
                        $dsn = "mysql:host=$host;dbname=$database";
                        self::$connection = new PDO($dsn, $user,  self::$options);
                }
        }

        /**
         * Executes a query and returns the PDO statement
         * @param array $params An array where the first item represents the query and the other items are its parameters.
         * @return \PDOStatement PDO statement
         */
        private static function executeStatement($params)
        {
                $insert = array_shift($params);
                $statement = self::$connection->prepare($insert);
                $statement->execute($params);
                return $statement;
        }

        /**
         * Executes a query and returns the number of affected rows.
         * Any other parameters will be passed into the query.
         * @param string $insert The query
         * @return int The number of affected rows
         */
        public static function query($insert) {
                $statement = self::executeStatement(func_get_args());
                return $statement->rowCount();
        }

        /**
         * Executes a query and returns the value of the first column of the first row.
         * Any other parameters will be passed into the query.
         * @param string $insert The query
         * @return mixed The value of the first column of the first row
         */
        public static function querySingle($insert) {
                $statement = self::executeStatement(func_get_args());
                $data = $statement->fetch();
                return $data[0];
        }

        /**
         * Executes a query and returns the first row of the result.
         * Any other parameters will be passed into the query.
         * @param string $insert The query
         * @return mixed An associative array representing the row or false in no data returned
         */
        public static function queryOne($insert) {
                $statement = self::executeStatement(func_get_args());
                return $statement->fetch(PDO::FETCH_ASSOC);
        }

        /**
         * Executes a query and returns all resulting rows as an array of associative arrays.
         * Any other parameters will be passed into the query.
         * @param string $insert The query
         * @return mixed An array of associative arrays or false in no data returned
         */
        public static function queryAll($insert) {
                $statement = self::executeStatement(func_get_args());
                return $statement->fetchAll(PDO::FETCH_ASSOC);
        }

        /**
         * Inserts data from an associative array into the database as a new row
         * @param string $table The table name
         * @param array $data The associative array where keys preresent columns and values their values
         * @return int The number of affected rows
         */
        public static function insert($table, $data) {
                $keys = array_keys($table);
                self::checkIdentifiers(array($table) + $keys);
                $insert = "
                        INSERT INTO `$table` (`" . implode('`, `', $keys) . "`)
                        VALUES (" . str_repeat('?,', count($data) - 1) . "?)
                ";
                $params = array_merge(array($insert), array_values($data));
                $statement = self::executeStatement($params);
                return $statement->rowCount();
        }

        /**
         * Executes an update and passes data from an associative array to it
         * @param string $table The table name
         * @param array $data The associative array where keys preresent columns and values their values
         * @param string $condition A string containing the condition (WHERE)
         * @return mixed The number of affected rows
         */
        public static function update($table, $data, $condition) {
                $keys = array_keys($data);
                self::checkIdentifiers(array($table) + $keys);
                $insert = "
                        UPDATE `$table` SET `".
                        implode('` = ?, `', array_keys($data)) . "` = ?
                        $condition
                ";
                $params = array_merge(array($insert), array_values($data), array_slice(func_get_args(), 3));
                $statement = self::executeStatement($params);
                return $statement->rowCount();
        }

        /**
         * Returns the ID of the last inserted row
         * @return mixed The ID of the last inserted row
         */
        public static function getLastId()
        {
                return self::$connection->lastInsertId();
        }

        /**
         * Quotes a given string to protect it against the SQL injection
         * @param string $string The string
         * @return mixed The quoted string
         */
        public static function quote($string)
        {
                return self::$connection->quote($string);
        }

        /**
         * Checks whether given identifiers don't contain dangerous characters
         * @param array $identifiers The identifiers
         * @throws \Exception
         */
        private static function checkIdentifiers($identifiers)
        {
                foreach ($identifiers as $identifier)
                {
                    if (!preg_match('/^[a-zA-Z0-9\_\-]+$/u', $identifier)) {
                throw new Exception('Dangerous identifier in SQL query');
            }
        }
        }
}

editor.php

<?php
session_start();

require('Dbb.php');

$article = array(
        'article_id' => '',
        'title' => '',
        'content' => '',
        'description' => '',
);
if ($_POST)
{
        if (!$_POST['article_id'])
        {
                Db::insert('
                        INSERT INTO article (title, content, description)
                        VALUES (?, ?, ?)
                ', $_POST['title'], $_POST['content'], $_POST['description']);
        }
        else
        {
                Db::insert('
                        UPDATE article
                        SET title=?, content=?,  description=?
                        WHERE article_id=?
                ', $_POST['title'], $_POST['content'], $_POST['description'], $_POST['article_id']);
        }
        header('Location: index.php');
        exit();
}
else
?>
<!DOCTYPE html>
<html lang="en">
<head>
        <meta charset="utf-8" />
        <link rel="stylesheet" href="style.css" type="text/css" />
        <title>Article editor</title>
</head>

<body>
    <header>
                        <div id="logo"><h1></h1></div>
                <nav>
                        <ul>
                            <li><a href="home.php">Home</a></li>
                                <li><a href="about.php">About us</a></li>
                                <li><a href="members.php">members</a></li>
                                <li><a href="contact.php">Contact</a></li>


                        </ul>
                </nav>
</header>
        <article>
                <div id="centerer">
                        <header>
                                <h1>Article editor</h1>
                        </header>
                        <section>

                                <form method="post">
                                        <input type="hidden" name="article_id" value="<?= htmlspecialchars($article['article_id']) ?>" /><br />
                                        title<br />
                                        <input type="text" name="title" value="<?= htmlspecialchars($article['title']) ?>" /><br />
                                        Description<br />
                                        <input type="text" name="description" value="<?= htmlspecialchars($article['description']) ?>" /><br />
                                        <textarea name="content"><?= htmlspecialchars($article['content']) ?></textarea>
                                        <input type="submit" value="Submit" />
                                </form>
                        </section>
                        <div class="clear"></div>
                </div>
        </article>
        <script type="text/javascript" src="//cdn.tinymce.com/4/tinymce.min.js"></script>
        <script type="text/javascript">
                tinymce.init({
                        selector: "textarea[name=content]",
                        plugins: [
                                "advlist autolink lists link image charmap print preview anchor",
                                "searchreplace visualblocks code fullscreen",
                                "insertdatetime media table contextmenu paste"
                        ],
                        toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image",
                        entities: "160,nbsp",
                        entity_encoding: "named",
                        entity_encoding: "raw"
                });
        </script>
     <footer>
                        Made by &copy;<a href="http://www.facebook.com/lawnj">lawrence</a>
                </footer>
</body>
</html>

\---

insert has only 2 parameters - first is table (String) and then data (array). So you have to change it in this:

Db::insert('article', array(
    'title' => $_POST['title'],
    'content' => $_POST['content'],
    'description' => $_POST['description']
));

For update use normally function query. So for edit article you will use this:

Db::query('
        UPDATE article
        SET title=?, content=?, url=?, description=?
        WHERE article_id=?
', $_POST['title'], $_POST['content'], $_POST['url'], $_POST['description'], $_POST['article_id']);

I hope I helped you and next time you can use forum.

In the PHP code for the editor.php file above, both the INSERT and UPDATE queries have

$_POST['keywords']

in it, however the database was not set up to accept this field, am I to assume this is an error in your code or am I going to see this come into effect later in another chapter?

I thought it best to mention, that I have removed these two from my code to allow the article to be added to the database.

There is a missing database file in zip folder

Hi Sid, all the DB commands are in the articles, you can create the DB easily.