Copy Seitenklassen into Prak2

src/Praktikum/Prak2/Page.php

+<?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", "YOUR_DATABASE");
+
+        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);
+        }
+    }
+
+    /**
+     * Closes the DB connection and cleans up
+     */
+    public function __destruct()
+    {
+        // to do: close database
+    }
+
+    /**
+     * 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");
+
+        // to do: handle all parameters
+        // to do: output common beginning of HTML code
+    }
+
+    /**
+     * Outputs the end of the HTML-file i.e. </body> etc.
+	 * @return void
+     */
+    protected function generatePageFooter():void
+    {
+        // to do: output common end of HTML code
+    }
+
+    /**
+     * 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"). 
+//? >
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src/Praktikum/Prak2/PageTemplate.php

+<?php declare(strict_types=1);
+// UTF-8 marker äöüÄÖÜ߀
+/**
+ * Class PageTemplate 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     PageTemplate.php
+ * @package  Page Templates
+ * @author   Bernhard Kreling, <bernhard.kreling@h-da.de>
+ * @author   Ralf Hahn, <ralf.hahn@h-da.de>
+ * @version  3.1
+ */
+
+// to do: change name 'PageTemplate' throughout this file
+require_once './Page.php';
+
+/**
+ * This is a template for top level classes, which represent
+ * a complete web page and which are called directly by the user.
+ * Usually there will only be a single instance of such a class.
+ * The name of the template is supposed
+ * to be replaced by the name of the specific HTML page e.g. baker.
+ * The order of methods might correspond to the order of thinking
+ * during implementation.
+ * @author   Bernhard Kreling, <bernhard.kreling@h-da.de>
+ * @author   Ralf Hahn, <ralf.hahn@h-da.de>
+ */
+class PageTemplate extends Page
+{
+    // to do: declare reference variables for members 
+    // representing substructures/blocks
+
+    /**
+     * Instantiates members (to be defined above).
+     * Calls the constructor of the parent i.e. page class.
+     * So, the database connection is established.
+     * @throws Exception
+     */
+    protected function __construct()
+    {
+        parent::__construct();
+        // to do: instantiate members representing substructures/blocks
+    }
+
+    /**
+     * Cleans up whatever is needed.
+     * Calls the destructor of the parent i.e. page class.
+     * So, the database connection is closed.
+     */
+    public function __destruct()
+    {
+        parent::__destruct();
+    }
+
+    /**
+     * Fetch all data that is necessary for later output.
+     * Data is returned in an array e.g. as associative array.
+	 * @return array An array containing the requested data. 
+	 * This may be a normal array, an empty array or an associative array.
+     */
+    protected function getViewData():array
+    {
+        // to do: fetch data for this view from the database
+		// to do: return array containing data
+    }
+
+    /**
+     * First the required data is fetched and then the HTML is
+     * assembled for output. i.e. the header is generated, the content
+     * of the page ("view") is inserted and -if available- the content of
+     * all views contained is generated.
+     * Finally, the footer is added.
+	 * @return void
+     */
+    protected function generateView():void
+    {
+        $data = $this->getViewData(); //NOSONAR ignore unused $data
+        $this->generatePageHeader('to do: change headline'); //to do: set optional parameters
+        // to do: output view of this page
+        $this->generatePageFooter();
+    }
+
+    /**
+     * Processes the data that comes via GET or POST.
+     * If this page is supposed to do something with submitted
+     * data do it here.
+	 * @return void
+     */
+    protected function processReceivedData():void
+    {
+        parent::processReceivedData();
+        // to do: call processReceivedData() for all members
+    }
+
+    /**
+     * This main-function has the only purpose to create an instance
+     * of the class and to get all the things going.
+     * I.e. the operations of the class are called to produce
+     * the output of the HTML-file.
+     * The name "main" is no keyword for php. It is just used to
+     * indicate that function as the central starting point.
+     * To make it simpler this is a static function. That is you can simply
+     * call it without first creating an instance of the class.
+	 * @return void
+     */
+    public static function main():void
+    {
+        try {
+            $page = new PageTemplate();
+            $page->processReceivedData();
+            $page->generateView();
+        } catch (Exception $e) {
+            //header("Content-type: text/plain; charset=UTF-8");
+            header("Content-type: text/html; charset=UTF-8");
+            echo $e->getMessage();
+        }
+    }
+}
+
+// This call is starting the creation of the page. 
+// That is input is processed and output is created.
+PageTemplate::main();
+
+// 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"). 
+//? >
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