<?php declare(strict_types=1);
// UTF-8 marker äöüÄÖÜ߀
/**
* Class Page for the exercises of the EWA lecture
* Demonstrates use of PHP including class and OO.
* Implements Zend coding standards.
* Generate documentation with Doxygen or phpdoc
*
* PHP Version 7.4
*
* @file Page.php
* @package Page Templates
* @author Bernhard Kreling, <bernhard.kreling@h-da.de>
* @author Ralf Hahn, <ralf.hahn@h-da.de>
* @version 3.1
*/
/**
* This abstract class is a common base class for all
* HTML-pages to be created.
* It manages access to the database and provides operations
* for outputting header and footer of a page.
* Specific pages have to inherit from that class.
* Each derived class can use these operations for accessing the database
* and for creating the generic parts of a HTML-page.
*
* @author Bernhard Kreling, <bernhard.kreling@h-da.de>
* @author Ralf Hahn, <ralf.hahn@h-da.de>
*/
abstract class Page
{
// --- ATTRIBUTES ---
/**
* Reference to the MySQLi-Database that can be used
* by all operations of the class or inherited classes.
*/
protected MySQLi $_database;
// --- OPERATIONS ---
/**
* Connects to DB and stores
* the connection in member $_database.
* Needs name of DB, user, password.
*/
protected function __construct()
{
error_reporting(E_ALL);
$host = "localhost";
/********************************************/
// This code switches from the the local installation (XAMPP) to the docker installation
if (gethostbyname('mariadb') != "mariadb") { // mariadb is known?
$host = "mariadb";
}
/********************************************/
$this->_database = new MySQLi($host, "public", "public", "pizzaservice");
if ($this->_database->connect_errno) {
throw new Exception("Connect failed: " . $this->_database->connect_errno);
}
// set charset to UTF8!!
if (!$this->_database->set_charset("utf8")) {
throw new Exception($this->_database->error);
}
}
public function __destruct() // Closes the DB connection
{
$this->_database->close();
}
/**
* Generates the header section of the page.
* i.e. starting from the content type up to the body-tag.
* Takes care that all strings passed from outside
* are converted to safe HTML by htmlspecialchars.
*
* @param string $title $title is the text to be used as title of the page
* @param string $jsFile path to a java script file to be included, default is "" i.e. no java script file
* @param bool $autoreload true: auto reload the page every 5 s, false: not auto reload
* @return void
*/
protected function generatePageHeader(string $title = "", string $jsFile = "", bool $autoreload = false):void
{
$title = htmlspecialchars($title);
header("Content-type: text/html; charset=UTF-8");
//--------------------------------
if ($autoreload) {
header("Refresh: 10;");
}
//-------------------------------------
echo <<< HTML
<!DOCTYPE html>
<html lang="de">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>{$title}</title>
<link rel="stylesheet" href="./CSS/test.css">
</head>
<body>
HTML;
if (is_file($jsFile)) {
echo "<script src='{$jsFile}'></script>\n";
}
}
/**
* Outputs the end of the HTML-file i.e. </body> etc.
* @return void
*/
protected function generatePageFooter():void
{
echo <<< HTML
</body>
</html>
HTML;
}
/**
* Processes the data that comes in via GET or POST.
* If every derived page is supposed to do something common
* with submitted data do it here.
* E.g. checking the settings of PHP that
* influence passing the parameters (e.g. magic_quotes).
* @return void
*/
protected function processReceivedData():void
{
}
} // end of class
// Zend standard does not like closing php-tag!
// PHP doesn't require the closing tag (it is assumed when the file ends).
// Not specifying the closing ? > helps to prevent accidents
// like additional whitespace which will cause session
// initialization to fail ("headers already sent").
//? >