Website Development with PHP and MySQL Saving Data

What you will achieve this week! Submitting data to the server Saving data on a server using files

: Customer browser request service access page interpret set data present html return html get data databasescripting language web server Reminder of the general process

What can we do with Forms? Standard HTML tags which: –Collect user input –Specify where to send the input –Specify how to send the input to be processed HTML tags simply provide an interface to allow user interaction Input is handled by a separate script or program: –On the server e.g. via PHP, ASP, CGI etc. –In the browser e.g. JavaScript

More Input Types Radio buttons Choose ONE of the following: A B C Check boxes Choose ANY, ALL or NONE of the following: A B C

Even More Input Types Drop-down menus Text area

Secret Stuff? Passwords Care to give us a password? Hidden fields

Submit and Reset B uttons The submit button sends form data to be processed The reset button returns fields to original state

How to get data from a form to a program Specify how to send the form data –Specified with the method attribute –GET or POST or –If not specified – default is GET Specify where to send the form data –Specified by the action attribute –Usually a script or program – can be local or full URL

The GET Method Client makes an HTTP GET request for a script –Form data is appended to the script URL as name/value pairs – a querystring –The script has access to values sent in the querystring In addition –Input data can be hard-coded directly in a URL No need for a form –Results can be bookmarked

The POST Method Client makes an HTTP POST request for a script –Form data is sent as name/value pairs in the body of the request In addition –Useful for large amounts of data Browser may truncate a long querystring –Data is not visible in the URL –Results cannot be bookmarked

Form Processing Scripts Scripts are run by the web server via a web server application –CGI, PHP, ASP, ColdFusion etc… Scripts can be written in almost any language –PHP, VBScript, Perl, CFML etc… –Language may depend on web server application(s) Scripts receive form input from via GET or POST –Process input based on instructions in the script Create an message Perform database query Write information to a file Generate a web page

Form Processing Query database? Name: Arnold Comments: “Nice website!"... User submits form to web server Web server passes form data to processing script Write a file? Send ? Return a web page?

Submitting data to server through forms Simple examples that echo the submitted data back

: customer simpleTextBox.htmwebServerechoName.php enter name submit submit(echoName.php3) open($name) display

Name test a PHP page to process the form a variable to pass to the PHP page

echoName.php

: customer calculator.htmwebServercalculatorResult.php enter numbers submit submit(calculatorResult.php3) open($num1,$num2) display

Number 1 Number 2 test

calculatorResult.php

Saving data using files

: customer nameAddress.htmwebServersaveAddress.phpnameAddress enter name enter address submit submit(saveAddress.php) open($name,$address) open write close display

int fopen (string filename, string mode) mode may be any of the following:  'r' - Open for reading only; place the file pointer at the beginning of the file.  'r+' - Open for reading and writing; place the file pointer at the beginning of the file.  'w' - Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.  'w+' - Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.  'a' - Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it.  'a+' - Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it.

string sprintf (string format [, mixed args...]) The format string is composed of zero or more directives: ordinary characters (excluding %) that are copied directly to the result, and conversion specifications, each of which results in fetching its own parameter. b - the argument is treated as an integer, and presented as a binary number. c - the argument is treated as an integer, and presented as the character with that ASCII value. d - the argument is treated as an integer, and presented as a decimal number. f - the argument is treated as a double, and presented as a floating-point number. o - the argument is treated as an integer, and presented as an octal number. s - the argument is treated as and presented as a string. e.g. sprintf(“%d is the number of %s in a %y”, 12, “months”, “year”) results in “12 is the number of months in a year”

Name Address Test

saveAddress.php

Guestbook Application We need: A form A file (or database table) to hold the data entered via the form Some means of reading the data from the file so that we can see it We will look into this case study further when we move onto databases.

So, what have we got so far? A means of collecting data from the user A means of transmitting it to the server A means of recording it on the server