introduction to php and server side technology. slide 2 php history created in 1995 php 5.0 is the...
TRANSCRIPT
Introduction to PHP and Server Side
Technology
Slide 2
PHP History Created in 1995 PHP 5.0 is the current version
It’s been around since 2004
Slide 3
General PHP Characteristics (1) PHP is made up of a PHP scripting block
PHP scripting blocks can appear anywhere in a Web page
In addition to PHP scripting blocks, PHP documents typically contain HTML
A page having embedded PHP script must have a file suffix of .php
Slide 4
General PHP Characteristics (2) Like ASP.NET PHP is server-side
technology It runs on nearly all Web servers There is an IIS version
It’s open source It talks to databases
MySQL and others Facebook is a PHP application
Slide 5
General PHP Characteristics (2) PHP works with XML PHP supports AJAX PHP supports cookies
Slide 6
The Basics of PHP Syntax PHP scripts always appears between <?php and ?> PHP statements always end in a semi-
colon Comments have the same format as
JavaScript PHP KEYWORDS ARE NOT CASE
SENSITIVE BUT VARIABLE NAMES ARE
Slide 7
A First PHP Program As in <html> <body><?phpecho "Hello";?> </body></html>
Slide 8
PHP Variables Like JavaScript, variables are ‘loosely
typed’ Variables can be declared anywhere in a
PHP script Variable names
Must begin with a letter or underscore ‘_’ character
The remaining characters can be letters, numbers or the underscore
Variables cannot contain spaces
Slide 9
PHP Variables (Declaring) Variable declarations begin with the
dollar sign ‘$’, followed by the variable name
An equals sign and value follow the declaration
Examples:$userName = “joe”;
$pi = 3.14;
Slide 10
PHP Variables (Scope) Global variables are declared outside of a
function Use the global keyword to access variables
from a function
Local variables are declared within a function
Works the same way as JavaScript
Slide 11
Using Numeric Variables (1) Arithmetic operations work similarly in PHP
and JavaScript Use print or echo to write output
print returns 1 while echo returns nothing Use the $ to reference all variable names
$x = 10;
$y = 100;
print $x + $y; /* 110 */
Slide 12
Using Numeric Variables (2) The following prints 10 + 100 because
the value is quoted
$x = 10;
$y = 100;
print "$x + $y";
Slide 13
PHP Strings (Introduction) Strings work in PHP the same way they
work in other languages There are several string functions:
http://w3schools.com/php/php_ref_string.asp
The dot (.) is the concatenation operator
Slide 14
PHP Data Types Similar to JavaScript
Slide 15
A First Server Round Trip Using Forms (1) Remember form widgets from
JavaScript <input type=“text”> and so on Remember widgets are contained in a
form Widgets are visible from PHP script so
we can process their contents on the server
Slide 16
A First Server Round Trip Using Forms (2) The following form posts to the page
named Welcome.php (action attribute)
<form action="welcome.php" method="post">
Name: <input type="text" name="fname" />
Age: <input type="text" name="age" />
<input type="submit" />
</form>
Slide 17
A First Server Round Trip Using Forms (3) Welcome.php contains the script to
process the posted data<html>
<body>
Welcome <?php echo $_POST["fname"]; ?>!<br />
You are <?php echo $_POST["age"]; ?> years old.
</body>
</html>
Slide 18
A First Server Round Trip Using Forms (4)
Slide 19
GET and POST (Introduction) There are two basic ways to send data
back to a Web server We call these HTTP verbs
In all there are about 30 verbs http://annevankesteren.nl/2007/10/http-me
thods Both GET and POST send data to Web
servers
Slide 20
HTTP GET GET sends is data through the URL itself
as a query string The URL looks something like this
http://localhost/PhpProjectDemo1/welcome.php?fname=zaphod&age=42
<input> values appear after the ? Data appears as key=value pairs A & separates each key=value pair You don’t write the URL – HTTP does!
Slide 21
HTTP POST The request data does not appear inside
the query string Data is sent in the HTTP header itself
It’s possible to pull this data out of the header
Slide 22
HTTP GET and POST (Comparison) GET
Query strings are small (100 characters) Posted data is visible It’s possible to bookmark the page
PUT Large data blocks can be posted Posted data is hidden Page cannot be bookmarked
Slide 23
Reading Posted Data $_GET and $_POST retrieve data send to
the server via a GET or POST, respectively
They are built-in functions Pass the ID of the input control as an
argument
Slide 24
Example
<html>
<body>
Welcome <?php echo $_GET["fname"]; ?>!<br />
You are <?php echo $_GET["age"]; ?> years old.
</body>
</html>
Slide 25
PHP Functions (Introduction) PHP has built-in functions just like any
language In all, there are about 700 so we will not
get to all of them Refer to
http://w3schools.com/php/default.asp for a categorized list
Slide 26
PHP Functions (Syntax) It all looks just about like JavaScript
(except the $ notation for variables) Functions and accept 0, 1 or many
arguments Functions and return a value
Again, the arguments are loosely typed
Slide 27
Declaring a PHP Function (Example) Declare a function named ShowFooter<?php
function ShowFooter()
{
print("<br />");
print(“Rendered " . date("y-m-d"));
print("<br />");
}
?>
Slide 28
Calling a Function (Example) Call the ShowFooter function shown
previously
<?php ShowFooter(); ?>