CS 174: Web Programming October 14 Class Meeting Department of Computer Science San Jose State University Fall 2015 Instructor: Ron Mak

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Hidden HTML Form Input Fields  So far, a data submitted by an HTML form have been explicitly entered by the user. text fields checkboxes radio button select menus  A “hidden” input field: Send data from an HTML form to the server in a way that is not displayed by the web page. 2

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Receiving Client Data by the Server  Send data to the server using get or post. Corresponding ways for PHP code on the server to receive the data:  Older ways to receive data is via the PHP superglobals: $_REQUEST combines $_GET and $_POST. 3 $first = $_GET ( "firstName"); $language = $_POST("language"); $direction = $_REQUEST("direction"); $first = filter_input(INPUT_GET, "firstName"); $language = filter_input(INPUT_POST, "language");

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Input Filtering  An optional third parameter specifies either a sanitizing filter or a validation filter. Example:  A sanitizing filter strips off certain characters.  A validating filter checks the input for validity. 4 if (!filter_input(INPUT_GET, " ", FILTER_VALIDATE_ )) { echo(" is not valid"); } else { echo(" is valid"); }

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Input Filtering, cont’d 5 Filter constantIDDescription FILTER_VALIDATE_BOOLEAN258Validates a boolean FILTER_VALIDATE_ 274Validates an address FILTER_VALIDATE_FLOAT259Validates a float FILTER_VALIDATE_INT257Validates an integer FILTER_VALIDATE_IP275Validates an IP address FILTER_VALIDATE_REGEXP272Validates a regular expression FILTER_VALIDATE_URL273Validates a URL FILTER_SANITIZE_ 517Removes all illegal characters from an address FILTER_SANITIZE_ENCODED514Removes/Encodes special characters FILTER_SANITIZE_MAGIC_QUOTES521Apply addslashes() FILTER_SANITIZE_NUMBER_FLOAT520Remove all characters, except digits, +- and optionally.,eE FILTER_SANITIZE_NUMBER_INT519Removes all characters except digits and + - FILTER_SANITIZE_SPECIAL_CHARS515Removes special characters FILTER_SANITIZE_STRING513Removes tags/special characters from a string FILTER_SANITIZE_STRIPPED513Alias of FILTER_SANITIZE_STRING FILTER_SANITIZE_URL518Removes all illegal character from s URL FILTER_UNSAFE_RAW516Do nothing, optionally strip/encode special characters FILTER_CALLBACK1024Call a user-defined function to filter data Default

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP is Object-Oriented  The object-oriented features and syntax of PHP resemble those of Java: classes and objects abstract classes inheritance interfaces  PHP also has traits. Add functionality to a class without inheritance. 6

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Classes 7 class Pet { public $name; function __construct($pet_name) { $this->name = $pet_name; } function eat() { /*... */ } function sleep() { /*... */ } function play() { /*... */ } } The constructor is always named __construct (two underscores). oo/Pet.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Inheritance 8 class Cat extends Pet { function play() { parent::play(); } Scope resolution operator ::  As with Java, a PHP class can inherit from at most one superclass. oo/Pet.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Objects 9 $cat = new Cat('Eliza'); $pet = new Pet('Norska'); $cat->eat(); $pet->sleep(); // Delete the objects unset($cat, $pet); oo/Pet.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Abstract Classes 10 abstract class Shape { abstract public function getArea(); abstract public function getPerimeter(); } require('Shape.php'); class Triangle extends Shape { private $_sides = array(); private $_perimeter = NULL; function __construct($s0 = 0, $s1 = 0, $s2 = 0) { /*... */ } public function getArea() { /*... */ } public function getPerimeter() { /*... */ } } oo/Shape.php oo/Triangle.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Interfaces 11 interface Crud { public function create($data); public function read(); public function update($data); public function delete(); } require('Crud.php'); class User implements Crud { /*... */ function create($data) { /*... */ } function read() { /*... */ } function update($data) { /*... */ } public function delete() { /*... */ } } oo/Crud.php oo/User.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Traits  Traits add functionality to a class without class inheritance. They help overcome some of the restrictions of single inheritance.  A class can use several traits.  Several classes can share traits. 12

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Traits, cont’d 13 trait Debug { public function dumpObject() { $class = get_class($this); $attributes = get_object_vars($this); $methods = get_class_methods($this); echo " Information about the $class object "; echo ' Attributes '; foreach ($attributes as $k => $v) { echo " $k: $v "; } echo ' '; echo ' Methods '; foreach ($methods as $v) { echo " $v "; } echo ' '; } oo/Debug.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Traits, cont’d require('Shape.php'); require('Debug.php'); class Rectangle extends Shape { use Debug; public $width; public $height; function __construct($w, $h) { $width = $w; $height = $h; } function getArea() { return $width * $height; } function getPerimeter() { return 2*($width + $height); } } oo/Rectangle.php

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak PHP Traits, cont’d 15 require('Rectangle.php'); $r = new Rectangle(42, 37); $r->dumpObject(); oo/traittest.php Demo

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Sample Midterm Question #1  Write the HTML and JavaScript code to allow a user to input a credit card number and then validate and reformat the number. The user must enter the card number with spaces such as and the web page should submit the number without spaces. Pop up an alert that displays the reformatted number that is being submitted, or the alert should display an error message if the user entered the number in the wrong format. 16

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Sample Midterm Question #1, cont’d 17

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Solution to Question #1 18 Enter your credit card number <input type = "text" value = "" id = "ccNumber" />

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Solution to Question #1, cont’d 19 function validate() { ccNumber = document.getElementById("ccNumber"); ccn = ccNumber.value; ccnRE = /(\d{4}) (\d{4}) (\d{4}) (\d{4})/; if (!ccn.match(ccnRE)){ alert("Invalid credit card number format."); return false; } else { ccn = ccn.replace(ccnRE, "$1$2$3$4"); ccNumber.value = ccn; alert("Submitted: " + ccNumber.value); return true; } }

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Sample Midterm Question #2 20  Normalize this table to 2NF.  Represent your normalized tables with a simple generic diagram or with a crow’s feet ER diagram. Show the field names, but you can leave off the data types. Identify the primary and foreign keys with (PK) and (FK), respectively, next to the field names. Indicate which table each foreign key refers to.

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Solution to Question #2 21 (FK)

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Sample Midterm Question #3  Write an SQL statement that makes this query: Who are all the teachers of student John Doe and what are the corresponding subjects? 22

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Solution to Question #3 23 mysql> SELECT teacher.first, teacher.last, subject -> FROM student, teacher, class, student_class -> WHERE student.first = 'John' AND student.last = 'Doe' -> AND student.id = student_id AND class.code = class_code -> AND teacher.id = class.teacher_id -> ; | first | last | subject | | Tom | Rogers | Java programming | | Art | Thompson | Data structures | | John | Lane | Software engineering | rows in set (0.02 sec)

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Sample Midterm Question #4  Write the PHP statements that include a prepared statement to make the same query for any student when given the student’s first and last name, and then return the result set as an associative array. You may assume that variable $con already contains the connection to the database, and that variables $first and $last contain the name of a student. 24

Computer Science Dept. Fall 2015: October 14 CS 174: Web Programming © R. Mak Solution to Question #4 25 $query = "SELECT teacher.first, teacher.last, subject ". "FROM student, teacher, class, student_class ". "WHERE student.first = :first ". "AND student.last = :last ". "AND student.id = student_id ". "AND class.code = class_code ". "AND teacher.id = class.teacher_id"; $ps = $con->prepare($query); $ps->bindParam(':first', $first); $ps->bindParam(':last', $last); $ps->execute(); $ps->setFetchMode(PDO::FETCH_ASSOC);