Charlie LoveEducation Support Officer

Aberdeen City Council@charlie_love

Software development using Server-side scripting

• an integrated approach to Higher Computing Science.

• approaches to increase teaching time• reduce the assessment • strategies for integrated delivery blending

components of the SDD and ISDD units• use contemporary web technologies:

Apache/Mysql/PHP/JavaScript

Higher Computing Science

Software Design and

Development

Information Systems Design

and Development

Assessment

Assessment

Information Systems Design

and Development

Software Design and Development Integrating the delivery of

units using a server side scripting language

will increase teaching time and decrease time take for assessment

Using *AMP stack

+ ++

Get *AMP on your computers

• Education Scotland Blog post with information• http://glo.li/edscot-amp

• MAMP• EasyPHP• XAMMP• WAMP• etc.

Building solutions

• Agile methodologies • Interative prototyping • Design->Build->Test->Repeat• Working code• Limited Feature Set -> Expanded Feature Set

sub-programs/routines

defined by their name and arguments (inputs and outputs)• PHP uses functions which typically return a

single value.• Use of &parameter passes values by

reference to the PHP function (essentially creating a subprogram)

including parameter passing (value and reference, formal and actual)

function read_users( $file, &$user_id, &$user_name, &$user_image, &$password_string, $index ) {

$textline = fgets($file); $textarray = explode(',',$textline);$user_id[$index] = trim($textarray[0])$user_name[$index] = trim($textarray[1]); $user_image[$index] = trim($textarray[2]);$password_string[$index] = trim($textarray[3]);

}

methods

• methods are subroutines associated with an object

• they have access to the objects data.• PHP includes support for object oriented

programming• Use the MySQL API to show methods on

database objects

If ($result = $mysqli->query("SELECT * FROM user WHERE user_id = '" . $login_user_id . "'")) { $obj = $result->fetch_object();$user_id = $obj->user_id;$user_name = $obj->user_name;$user_image = $obj->user_image; $result->close();}

Data types and structures• string • numeric

(integer and real)• Boolean

$mysting=“Some text”;$integer = 12;$real =15.232;$is_set = true;

• Records - Implement as an array of objectsclass Owner{

public $year; public $measure; public $month; public $name;

}$names = array('Lars', 'James', 'Kirk', 'Robert');

for ($i = 1 ; $i <= 3 ; $i++) {

$owner = new Owner(); $owner->year = 2012; $owner->measure = $i; $owner->month = rand(1,12); $owner->name = array_rand($names); $owners[] = $owner;}

• sequential files (open, create, read, write, close) • fopen(filename, mode) – Creates and/or opens file– Mode is read and/or write and moves file pointer to

start or end of file.– http://www.php.net/manual/en/function.fopen.php

• fwrite($file, $textline);– $file is the file handle from opening the file– $textline is the line of text to be written

• fgets($file)– Reads line of text from the file

• fclose($file) – close file

Standard Algorithms

• input validation (server side) / server-side validation of online form data – Set up form in html– Process and validate form on submission– Processing happens at server– User interaction is required to create validation

loop

<?php$username="”;if (isset($_GET[’username'])) {

$error_found = false;$message = "username is accepted”;$username = $_GET[’username’];if(strlen($username) < 8 ) {

$error_found = true;$message = “Enter 8 or more characters”;

}echo "<div>" . $message . "</div>";

} if (($error_found) || (!isset($error_found))) { //show form if err found or 1st visit

?><form action="<?php echo $_SERVER[‘PHP_SELF’];?>" method="get"><input type="text" name="username" value="<?php echo $username;?>"><input type="submit" value="Submit" name="update"/></form>

<? php } ?>

Linear search• linear search function linear_search($needle, $haystack) {

for($i = 0; $i < count($haystack); $i++) {if ($needle == $i)

return true;}return false;

}

$haystack = array(1,2,3,4);$needle = 3;$found = linear_search($needle, $haystack);

Finding minimum and maximumInbuilt max and min functions do it out of the box

function findmax($array_of_values) {$current_max = $array_of_values[0];for($i = 1; $i < count($array_of_values); $i++) {if ($array_of_values[$i] > $current_max) {$current_max = $array_of_values[$i];}}return $current_max;

}

$my_array= array(12,25,23,14);$biggest_number = findmax($my_array);

count occurrences function count_values($val_to_count, $array_of_values) {

$counter = 0;for($i = 0; $i < count($array_of_values); $i++) {

if ($array_of_values[$i] == $val_to_count) {$counter++;

}}return $counter;

}

$my_array= array(12,25,23,14,72,83,12,12,63,25,14);$count_of_values = count_values(12, $my_array);

Coding (ISDD)

• scripting (database/web pages) • client-side scripting• server-side scripting• server-side validation of online form data

Structures and Links (Database)• MySQL • phpMyAdmin - Database front end– Can be used to generate SQL for coding– Web based – simplifies database management

Structures and Links (Web)• PHP, HTML, CSS, JavaScript all play well together<html> <head> <title><?php echo $title;></title> <style>

hr {color:sienna;} p {margin-left:20px;} body {background-image:url(“bg.gif");}

</style> <script> function show_message() {

alert(“hello there”); } </script> <body onLoad=“show_message();”>….

PHP and MySQL

//connect to the database using mysqli API$mysqli = new mysqli("localhost", "root", "root", ”mydatabase");if ($mysqli->connect_errno) {

echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;

die;}

Run a query and retrieve results

if ($result = $mysqli->query("SELECT * FROM my_table WHERE field_id = '" . $field_id . "'")){

$obj = $result->fetch_object();$my_field_id = $obj->field_id;$my_field1 = $obj->field1;$my_field2 = $obj->field2;

/* free result set */ $result->close();}

Write to the database$sql = mysqli('localhost','user','password','database');

$name = $_POST['name'];$age = $_POST['age']; $email = $_POST['email'];

$query = $sql->prepare("INSERT INTO `tablename` VALUES ('?','?','?');");

$query->bind_param("sis",$name,$age,$email); $query->execute();

Relationships in MySQL

Implemented using queries

SELECT * FROM table1, table2 WHERE table2.id = table1.hid

id field

12 Harry

13 Sally

14 Joe

15 Kirsty

id field hid3232 sweets 123233 candy 123234 chocolate 123235 popcorn 133236 soup 13

table1 table2

Search in MySQL

Implemented using queries

SELECT * FROM table1, table2 WHERE table1.id = 12;

SELECT * FROM table1, table2 WHERE table1.field LIKE “%Joe%”

AND WHERE table2.id = table1.hid ;

Assessment

• You need to show that the candidate has achieve all the Assessment Standards

• SDD Outcome 2 and ISDD Outcome 1 can be assessed in the same exercise

• Alternative evidence can be gathered as part of learning and teaching

• SDD Outcome 1 for part of this as well

Higher Assignment

• Assignment 1: Coding + Database (Diving Championship – available now)

• Assignment 2: Server Side Scripting – File handling– Linear Search– Server side scripting– Online database integration

• Assignment 3: Client Side Scripting– CSS– Browser based

Blog: http://charlielove.orgTwitter: @charlie_love