Programming PDF – PHP

PHP – Interaction with the client

Web Applications / Web Systems

Juan Pavón Mestras
Dep. Software Engineering and Artificial Intelligence
Facultad de Informática
Universidad Complutense Madrid

Licensed material Creative Commons

PHP – Interaction with the client

Forms

HTTP Protocol

 The browser (client, user agent) requests a resource (page

HTML, image, video, etc.) to a server
 Request: method that is used GET, POST, PUT, HEAD, etc.
 Header fields
 Blank line
 Body of the message (text): can carry parameters of the form
 The server responds by sending the resource or with a message of

error
 Line status: status code (OK, Error) and associated text
 Header fields
 Blank line
 Message body: the requested resource

Client

(Browser) [19659002] and

connection

1

request (GET / PO ST, …)

2

answer

80

x

Server

Juan Pavón – UCM 2012-13

close

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PHP

] Parameter passing

 The client request can take several parameters

 Normally they are obtained from a form

 How they are passed depends on the action indicated in the form

HTML in which they are collected data

 GET: information request (idempotent operation)

GET queryphonephone.php? customer = company1

• Parameters are passed as name = value pairs
• Several parameters can be passed in succession with &

 POST: requests that change server status

• Save or update data
• Send email
• Sort data

POST modify.php? Customer = company1 & phone = 917892893

Juan Pavón – UCM 2012-13

PHP

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4

Typical scenario of in teraction (with GET)

http: //localhost/CursoPHP/hola.html

hi.html

please, give your name:

By

Name:

procesaform.php

<? Php

?>

$ client = $ _ REQUEST [“cliente”];
echo "Hello $ client";

Juan Pavón – UCM 2012-13

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Typical scenario of interaction (with POST)

http: // localhost / CursoPHP / hello.html

hello.html

please, enter your name:

By

Name:

procesaform.php

<? Php

?>

$ client = $ _ REQUEST [“cliente”];
echo "Hello $ client";

Juan Pavón – UCM 2012-13

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Forms



 Set of controls that allow the user to interact
]  Usually to enter data and send it to the web server
 The browser sends only the data of the contained controls

in the form

 On the same page there may be several forms that send

data to the same or different agents

Enter your name:

POST "/procesaform.php "

name =" value "

Juan Pavón – UCM 2012-13

PHP

Forms

 Within a form there may be:

 Any typical element of a web page [19659002] • Paragraphs, images, divisions, lists, tables, etc.

 Form controls

• [19659083] •