1. ITS332

2. Overview HTTP Communication HTTP Communication for Web Static Dynamic
Dynamic Content
PHP
PHP Block
PHP Programming Style
Database
MySQL

3. HTTP Communication

4. HTTP Communication for Web
Static Web
The contents of the web are fixed, hard coded in the markup language (HTML)
(What you see is what you get).
used to display fixed information which most often does not need to be updated on a regular basis
Dynamic Web
The contents of the web are coded using client or server side scripting which requires special interpretation to produce interactive or dynamic elements in the page
search results
number of visitors
user login
message boards

5. HTTP Communication for Web – Static

6. HTTP Communication for Web – Static

7. HTTP Communication for Web – Dynamic

8. HTTP Communication for Web – Dynamic
HTML + JavaScript

9. HTTP Communication for Web – Dynamic
HTML + PHP

10. HTTP Communication for Web – Dynamic
HTML + PHP

11. HTTP Communication for Web – Dynamic Content

12. HTTP Communication for Web
Benefit of Dynamic Web Content
Have ability to customize pages for any given user.
Greater ease of modification and update.
Extended functionality (login, transactions, communication etc.)
Automating the site and allowing it to support itself. Less pages to manually create.

13. PHP PHP's name is an recursive acronym for: Hypertext Preprocessor
PHP script is an HTML- embedded scriting language
Designed to do something only after event occurs.
e.g. when user submit forms
A Server-Side language
the code resides on a host computer that serves Web pages to the requesting visitors (client).
PHP is easy to use for Web development because it has many built-in functions that make web programming simpler, so that programmers can focus on the logic of programming without wasting precious development time

14. PHP
client
server
URL request
HTML
PHP
Script request

15. PHP Block PHP code skeleton: First style Second style Third style
<? … ?>
Second style
<script language = “PHP”> … </script>
Third style

16. PHP Programming Style

17. Sending data to web browser
Use PHP built in functions
Example
echo ‘Hello Student’;
print “ How are you”;
Case-insensitive for function names
ECHO, echo, Echo
Other print functions
print_r, var_dump - value of variable
print_f - formatting what you print

18. White space, HTML and PHP
White spaces - blank lines, tabs and extra spaces
To alter spacing of finished web page, use
<br /> - line break
<p></p> - paragraph
To alter spacing of HTML source from PHP, use
echo() or print() over the course of several lines
\n (newline character) within double quotation
marks

19. Writing comments Important aspect to dynamic web site development
Viewable in the source but not in the browser window
PHP supports 3 type of comments
# this is a comment
// this is also a comment
/* this is a larger comment that spans two line */

20. Variables Rules of thumb Variable name must start with dollar sign ($)
Combination of strings, numbers and the underscore
First character after dollar sign cannot be a number
Case sensitive
Assigned value using equals sign (=)

21. String A quoted chunk of letters, numbers, spaces, punctuation ..
Example strings
‘hello’
‘software’
‘1000’
’12 January, 2006’
String variable – assign a string value to valid variable name
$today =’16 July, 2007’;
To print out
echo $today;
echo “Today is $today”;
Concatenation string
Addition of strings using period (.).
$day=‘12’;
$month=‘January’;
$year =‘2006’;
$today = $day . ’ ‘ . $month . ’ ‘ . $year;
Use it extensively when building database queries in later chapters

22. Numbers Valid number-type variables can be Arithmetic operators 8 3.14
Arithmetic operators
+ addition
- subtraction
* multiplication
/ division
% modular
++ increment
-- decrement

23. Numbers round() number_format() Functions $j = 3.14; $k = round( $j);
$p =20980;
$g=number_format($p);
$g=number_format($p,2);

24. Constant Specific data type Retain initial value throughout script
Cannot change once it has been set
Use define()
define (‘AGE’, ‘value’);
Print constant
echo ‘Hello, ‘ . AGE; OR
echo ‘Hello,’, AGE;

25. Single vs Double Quotation Marks
Single quote -> values treated literally
Double quote -> interpolated
Example:
$var =‘Hello’;
echo “var equal to $var”;
var equal to hello
echo ‘var equal to $var’;
var equal to $var
echo “\$var is equal to $var”;
$var is equal to hello

26. Single vs Double quotation marks“”
replace variables name with its value and a special character’s code (\$) with its represented value ‘’
display exactly what you type, except for the escaped single quote (\’) and the escape backslash(\\).

27. PROGRAMMING WITH PHP
PROGRAMMING WITH PHP

28. Discuss on.. Creating an HTML form Handling an HTML form
Conditional and Operators
Validating Form Data
Sending Values to A Script Manually
What are Arrays
For and While Loops

29. HTML form Managing HTML form with PHP involves 2 steps : Step 1:
Create HTML form with any text editor
HTML form (.htm/.html) is created using the HTML form tags and various input types.
Step 2:
Create PHP scripts that receives form data
PHP script (.php) is created to receives the submitted form data and handle it.

30. Handling HTML form Step 1: create html form Step 2:
create php scripts that receive form data

31. Step 1: create html form form.html
which page the form data will be send
how dat ais sent
(get or post)

32. Step 2: create php script procesform.php

33. Superglobal variable
If you have a text box in html form with name attribute age, PHP will store the text entered there in a variable called $age (registered global variable)
$age is similar to $_POST[‘age’] (superglobal variables)
eg : ( in HTML form)
eg : ( in PHP scripts)
echo “<p>Thank you, {$_POST[‘age’]} for the following comments”;
attributes
<p><b>Age: </b><input type ="text" name=“age" size="20" maxlength="40"/></p>

34. Conditional and Operators
Dynamic web frequently use conditionals to alter script behavior
3 primary terms – if, else, elseif
Syntax:
if (condition) {
// do something! }
} else {
// do something else!
if (condition1) {
// do something!
} elseif (condition2) {
// do something else!
} else { }

35. Conditional and Operators
Condition can be TRUE for any number of reasons. Below are common TRUE conditions:
$var, if $var has a value other than 0, an empty string or NULL
isset($var), if $var has any value other than NULL, including 0 and an empty string.
TRUE

36. Conditional and Operators
Comparative and Logical Operators
Symbol
Meaning
Type
example =
Is assigned the value of
Assignment
$n=1 ==
Is equal to
Comparison
$x==$y !=
Is not equal to
$x!=$y
<
Less than
$x < $y
>
Greater than
$x > $y

37. Conditional and Operators
switch
Used in place of a long if–elseif–else conditional
Syntax :
switch ($variable) {
case ‘value1’ :
// do this
break;
case ‘value2’ :
default : }

38. Validating Form Data
Use of conditionals and any number of functions, operators and expressions.
Common functions : empty(), strlen(), isset()

39. Aims of validating data
Why validate form?
To ensure that something was entered or selected in form elements.
To ensure that submitted data is of the right type (numeric, string, etc), of the right format (eg: addr), or a specific acceptable value (eg: $gender is either M or F)

40. Sending Values to a script manually
2 ways to pass a PHP script variables and values
Use HTML hidden input type
<input type=“hidden” name=”name” value=“Brian”/>
As long as this code is anywhere between the form tags, the variable $name will have a value of ‘Brian’ in the handling PHP script
To append a value to the handling PHP scripts URL
- Emulate the get method of an HTML form

41. The $source variable
Observe the action attribute in the form tag below :
appended!
The page (handle_calculator.php) that handles the form (calculator.html) will receive a $source variable to indicate where the data (hidden input) came from.
The $source variable need also be validated; is set or not and if it is set with value, is the value correct or not.

42. What are Arrays?
An array can hold multiple, separate pieces of information
List of values
Each value being a string or a number or even another array
Structured as a series of key-value pairs.
Each item in the list, there is a key associate with it.
Support 2 kind of arrays
Indexed – use numbers as the key
Associative – use strings as key

43. What are Arrays? Example – indexed Example – associative $artists
$states
Key
Value
Low 1
Aimee 2
Ani Difranco 3
Spiritualized
Key
Value MD
Maryland PA
Penssylvania IL
Illinois MO
Missouri

44. What are Arrays?
To retrieve a specific value from an array, refer to the array name, followed by the key, in square brackets
echo $artists[2];
echo $states[‘MD’];
To print, wrap array name with curly braces
echo “IL is the abbreviation for {$states[‘IL’]}.”;

45. Superglobal Arrays Very useful and powerful tool
By default, PHP uses several types of arrays
$_GET to store all of the variables and values sent via the get method
$_POST to store all of the variables and values sent via the post method
$_SESSION, $_COOKIE

46. Creating Arrays Syntax to create arrays Add an element at a time
$array[] =‘value’;
$array[] =‘value one’;
$array[‘key’] =‘more values’;
Use array() function to build an entire array
$array =array(‘key’ =>’value’, ‘key2’ => ‘value2’);
$array =array(‘value’,’value2’,’value3’);
Create an array of sequential numbers, use range()
$ten = range(1,10);

47. Accessing arrays Access every array element, use foreach loop:
Syntax :
foreach ($array as $value)
echo $value ;
Iterate through every element in $array, assigning each element value to the $value variable.
To access both the keys and values
foreach ($array as $key => $value)
echo “The array value at $key is $value”;

48. Multidimensional arrays
An array consisting of other arrays
Combine 2 arrays into 1 multidimensional array
$states = array (‘MD’ =>’MaryLand’, ‘IL’ =>’Illinois’);
$provinces = array (‘QC’ =>’Quebec’, ‘AB’ =>’Alberta’);
$abbr = array (‘US’ =>$states, ‘Canade =>$provinces’);
To access $states array
$abbr[‘US’];
To access Maryland
$abbr[‘US’][‘MD’]
To print out
echo “The US state whose abbreviation is MD is {$abbr[‘US’][‘MD’]}.”;

49. Array and strings
2 functions for converting between strings and arrays
$array = explode (separator, $string);
Turning a string into an array
$string =‘Jan-Feb-Mac-Apr-May’;
$array =explode (‘-’, $string);
$string = implode (glue, $array);
Turning an array to string
$string =implode (‘ , ’, $array);
$string= ‘Jan,Feb,Mac,Apr,May’;

50. Sorting Arrays Use built in PHP function
sort() – sort an array by value discarding the original keys
The array keys will be reset after the sorting process
Avoid use this function if key-value relationship is important.
asort() – sort an array by value while maintaining the key
ksort() – sort an array by key
Each of these can sort reverse order by changing them to
rsort() , arsort() , krsort()
shuffle() – to randomize the order of an array

51. For and While Loops
While loop
If the condition is still true, the loop will be executed
Syntax :
while (condition) {
// do something }
For loop
first the initial expression is run, checked the condition and if true, content of the loop is executed. After execution, checked closing expression with condition again.
for (initial expression; condition; closing expression) {