slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
PHP Lecture 2 Xingquan (Hill) Zhu xqzhu@cse.fau PowerPoint Presentation
Download Presentation
PHP Lecture 2 Xingquan (Hill) Zhu xqzhu@cse.fau

Loading in 2 Seconds...

play fullscreen
1 / 18

PHP Lecture 2 Xingquan (Hill) Zhu xqzhu@cse.fau - PowerPoint PPT Presentation


  • 344 Views
  • Uploaded on

PHP Lecture 2 Xingquan (Hill) Zhu xqzhu@cse.fau.edu PHP PHP overview PHP General Syntactic Characteristics PHP Output to browser Primitives, Operations, and Expressions Control Statement Array Function File access Cookie Session Form process PHP: Files

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'PHP Lecture 2 Xingquan (Hill) Zhu xqzhu@cse.fau' - jaden


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2
PHP
  • PHP overview
  • PHP General Syntactic Characteristics
  • PHP Output to browser
  • Primitives, Operations, and Expressions
  • Control Statement
  • Array
  • Function
  • File access
  • Cookie
  • Session
  • Form process

PHP

php files
PHP: Files
  • Deal with any file on the server

$fptr = fopen(filename, use_indicator)

  • Use indicators:
    • “r” read only, from the beginning
    • “r+” read and write, from the beginning
    • “w” write only, from the beginning (also creates the file, if necessary)
    • “w+” read and write, from the beginning (also creates the file, if necessary)
    • “a” write only, at the end, if it exists (creates the file, if necessary)
    • “a+” read and write, read at the beginning, write at the end
    • “b” binary file: on systems which differentiate between binary and text files

$fptr1=fopen(“test1.php”, “w+”); files.php

$fptr2=fopen(“test1.php”, “r+”);

PHP

php files4
PHP: Files
  • fopen could fail
    • it will return “false”
    • Use file_exists(filename) to determine whether file exists before trying to open it
    • Use fopen with “die”
    • Always use fclose(file_var) to close a file, after your reading/writing

Fopen.php

PHP

php write to files
PHP: Write to Files
  • $bytes_written = fwrite(file_var, string)
    • fwrite returns the number of bytes it wrote
    • Return “false” on error

fwrite.php

PHP

php reading files
PHP: Reading Files
  • Read all or part of the file into a string variable
    • $str = fread(file_var, #bytes)
    • To read the whole file, use filesize(file_name) as the second parameter
  • Read one line from the file
    • $line = fgets(file_var[, #bytes])
    • Reads characters until eoln, eof, or #bytes characters have been read
  • Read one character from the file
    • $ch = fgetc(file_var)
      • Control reading lines or characters with eof detection using feof (TRUE for eof; FALSE otherwise)

while(!feof($file_var))

{

$ch = fgetc($file_var);

}

Readingfile.php

PHP

php file access
PHP file access
  • Read the lines of the file into an array
    • array file ( string filename)
      • file() returns the file in an array
      • Each element of the array corresponds to a line in the file, with the newline still attached.
      • Upon failure, file() returns FALSE

File.phpFiltering.php

PHP

slide8
PHP
  • PHP overview
  • PHP General Syntactic Characteristics
  • PHP Output to browser
  • Primitives, Operations, and Expressions
  • Control Statement
  • Array
  • Function
  • File access
  • Cookie
  • Session
  • Form process

PHP

building a shopping cart
Building a Shopping Cart
  • What is a shopping cart
    • Putting things together and then check out.
    • A series of scripts that keep track of items a visitor picks to buy from your site until they proceed to the "checkout
  • Web server is basically stateless
    • HTTP is stateless
    • It does not store any information about a web client
      • Why?
    • Web server records nothing about the previous actions of a web client
      • It only knows the current web page the web browser is visiting
  • How are we going to keep our browser “continuously” connected to the server
    • So we can feel the we are connected to the server all the time
  • How are we going to collect information across different web pages
    • Cookie & Session
    • Hidden fields of a form
      • <input type = "hidden" name = “customername" value = “San Jose" />

PHP

cookie
Cookie
  • What is a cookie?
    • An message given to a web browser by a web server, then send back to the server each time the browser requests a page from the server.
  • What can cookie do for us?
    • Identify users and store client side information
    • Authenticate or identify a registered user
      • No need to sign in again every time they access a website
  • Where is the cookie located? How does it look like?
    • C:\Documents and Settings\YourLoginID\Local Settings\Temporary Internet Files
    • Cookie:hill@google.com
  • Will browser return all cookies to each server?
    • No, only those matched domains
    • Malicious cookies setting
  • Are cookies dangerous to my computer?
    • No
  • Is this a major privacy issue?
    • You could lose identify information
    • You have choices of not using any cookie

PHP

cookie11
Cookie
  • Create a cookie with setcookie
    • setcookie(cookie_name, cookie_value, lifetime)
      • setcookie("voted", "true", time() + 86400);
      • setcookie("voted", "true", time() + 60*60*24);
    • Is “lifetime” important?
      • Without this value, cookie expires right after you close the current web browser window.
      • Expired cookies will be deleted without sending back to the server
  • Cookies must be created before any other HTML is created by the script
    • Before <html><body>…were sent
  • How to access the cookie value
    • Using the $_COOKIE array
      • setcookie("visits“, $visitcount, time()+3600);
      • $visitcount = $_COOKIE["visits"];
    • Check whether a cookie has been set before
      • Isset($_COOKIE[“visits”])

Cookie_simple.phpcookie1.php

PHP

simple shopping cart
Simple Shopping Cart
  • How to update cookie value based on your choice?
    • $_SERVER["PHP_SELF"]
      • The name of the current script
    • Using implicit arrays for form values
      • $_POST
      • $_GET

Simpleupdate.php

Updatecookie.phpuppdatecookie1.php

PHP

simple shopping cart13
Simple Shopping Cart
  • At checkout page, summarize all the cookie values

Checkout.phpcheckout1.php

Checkoutmain.php

PHP

session tracking
Session Tracking
  • What is a session
    • SUN API: Provides a way to identify a user across more than one page request or visit to a Web site and to store information about that user
    • web applications make use of sessions to remember who you are
    • A session is available as long as the browser is opened
    • A session is closed as soon as the browser is closed or you go to another website
  • Why session?
    • Some users block cookies for privacy concerns
  • Are cookie & session same thing?
    • Cookie
      • cookies are normally stored in your hard disk
      • privacy
    • Session
      • A session aren't stored in your hard disk
      • Considered more secure

PHP

session tracking15
Session tracking
  • For session tracking, PHP creates and maintains a session tracking id
    • Create the id with a call to session_start with no parameters
    • Subsequent calls to session_start retrieves any session variables that were previously registered in the session
  • To create a session variable
    • $_SESSION['myVar'] = $myVarValue;
    • Check session

if(isset($_SESSION['myVar']))

{

print $_SESSION['myVar'];

$_SESSION['myVar']++;

}

  • Example: count number of pages visited

Session.phpmain_1.phpmain_2.php

PHP

form process
Form Process
  • Action property
    • Where to send form data
  • Method property
    • Post vs get
  • Each element has unique name
    • Using implicit arrays for form element access
      • $_POST
      • $_GET

Simpleform.htmlsimpleform.php

PHP

a complete shopping cart
A complete Shopping Cart
  • Client Side:
    • Set cookie for each page
    • Collect information across web pages
    • A summarization form (before user submit the order)
    • “Submission” -> invoke form processing program
  • Server Side:
    • A form processing program
    • Read form values from $_POST or $_GET array
    • Process and save values
    • Confirmation

formselection.phpformselection1.php formprocess.php

PHP

slide18
PHP
  • PHP overview
  • PHP General Syntactic Characteristics
  • PHP Output to browser
  • Primitives, Operations, and Expressions
  • Control Statement
  • Array
  • Function
  • File access
  • Cookie
  • Session
  • Form process

PHP