csc317 – internet programming csc318 – dynamic web application development

CSC317 – INTERNET PROGRAMMINGCSC318 – DYNAMIC WEB APPLICATION DEVELOPMENTBY: SITI NURBAYA ISMAILFACULTY of COMPUTER and MATHEMATICAL SCIENCES

Outline

How does a server side page work? Introduction to IIS/PWS ASP Requirements What is ASP? How ASP file looks like? Form Processing Using ASP JavaScript vs VBScript Other Server Scripting Language

Introduction to Server-Side Scripting


Basically, A Web requires two components: a Web server and a client The client is usually a browser (I.E/Firefox/Chrome/etc) Both the server & the client can communicate each other Must use a defined protocol to communicate The most common protocols are HTTP & FTP and also carried over an

underlying network protocol called TCP/IP The client sends an initialization (is a defined series of bytes) to start a

session, when the server receives the initialization request, it acknowledges the transmission by returning another series of bytes to the client

How does a server side page work?


The conversation between client & server continues in this back-and forth manner

You can imagine the conversation being conducted as follows:

How does a server side page work?

`

Hello!

Hello

Can you give me index.php file?

Okay, here is the index.php fileClient Side Server Side


You can choose either IIS/PWS as a web server to run your ASP file If you choose IIS, you must have access to a Windows NT 4.0 server with

IIS 4.0 or Windows 2000 Server with IIS 5.0 Or you can install PWS on your local hard disk and enables you to work

as same as IIS PWS/IIS designate a master directory on the hard drive that contains all

date and script file for use by Internet Server

Introduction to IIS/PWS


The default master directory is: \Inetpub You can place your ASP file under subdirectory: \wwwroot (Example: C:\

Inetpub\wwwroot\MyFirstAsp.asp) IIS/PWS have built-in intelligence that knows to route a request for a Web

page using HTTP to this directory.

Introduction to IIS/PWS


ASP Requirements


Stands for Active Server Pages An ASP is a Web page that is processed by a web server ASP is a Microsoft technology ASP is a program that runs inside a web server (IIS/PWS) An ASP file is just the same as an HTML file An ASP file can contain text, HTML, XML, and scripts An ASP file has the file extension ".asp"

What is ASP?


Dynamically edit, change or add any content of a Web page Respond to user queries or data submitted from HTML forms Access any data or databases and return the results to a browser Customize a Web page to make it more useful for individual users Provides security since your ASP code can not be viewed from the browser Since ASP files are returned as plain HTML, they can be viewed in any browser Clever ASP programming can minimize the network traffic

What ASP can do?


At top of the ASP file, we have this line of code

You can place ASP code anywhere in the ASP file, BUT the code must be within its opening and closing delimiters tag

How ASP file looks like?

<%@LANGUAGE = “JAVASCRIPT”%>

<%// the rest of your ASP code%>

Introduction to Server-Side ScriptingHow ASP file looks like?

<%@LANGUAGE=“JAVASCRIPT”%><%// it can be here%><html><head><title></title></head><body><%// it can be here%></body></html><%// it can be here%>

Introduction to Server-Side ScriptingHow ASP file looks like?

<%@LANGUAGE="JAVASCRIPT"%><html><head><title>My First ASP Page</title></head><body><% Response.Write("Hello World!"); %></body></html>


Remember how to create a complete HTML form with input fields?

Form Processing Using ASP

<%@LANGUAGE="JAVASCRIPT" CODEPAGE="1252"%><html><head><title>HTML and ASP</title></head><body><form name="form1" method="post" action="login.process.asp"> <p>Username: <input name="username" type="text" id="username"></p> <p>Password: <input name="password" type="password" id="password"></p> <p><input name="Login" type="submit" id="Login" value="Login"></p></form></body></html>


Okay, save that file on the previous slide as login.asp Notice that there is a value in action=“login.process.asp” It means, the

login process will be done at another ASP file, which is login.process.asp


<%@LANGUAGE="JAVASCRIPT" CODEPAGE="1252"%><%if(Request.Form("Login") == "Login"){

var username, password;username = Request.Form("username");password = Request.Form("password");Response.Write("Username: " + username + "<br>");Response.Write("Password: " + password);

}%>

<%@LANGUAGE="JAVASCRIPT" CODEPAGE="1252"%>// as usual, code above is compulsory<%// code below means, if Login button is clicked, then the code block will // be executedif(Request.Form("Login") == "Login"){

// variables declarationvar username, password; // 2 lines of codes below, show how to capture inputs from HTML// formusername = Request.Form("username");password = Request.Form("password");// 2 lines of codes below, show how to display the values on the// web pageResponse.Write("Username: " + username + "<br>");Response.Write("Password: " + password);

}%>


Why do we need to create a code if a button is clicked?

- To execute a specific code once the button is clicked- Sometimes, in a single form, we have more than 1 buttons. Each 1 has its own

specific (code|task)- By doing so, the system knows which code to be executed depending on

which button has been clicked


<%// code below means, if Login button is clicked, then the code block will // be executedif(Request.Form("Login") == "Login"){

// code block to be executed if button is clicked}%>


Why do we need to create a code if a button is clicked?


<%/* 1. code below means, if “Login” button is clicked, then the code block will be executed2. “Login” name can be replaced with any name, depending on the name of button you specified in the form*/if(Request.Form("Login") == "Login"){

// code block to be executed if button is clicked}%>


How to capture inputs from HTML form?

- Similar to JavaScript, you need to declare variables to hold values captured from form

- Request.Form(“<your_field_name>”) is used to capture the values before assign to variable- <your_field_name> is depending on names of input fields from text field,

drop down list, text area, radio button, and checkbox


<%// variables declarationvar username, password; /* 2 lines of codes below, show how to capture inputs from HTML form */username = Request.Form("username");password = Request.Form("password");%>


How to display value on the web page?

- Did you find any similarity with JavaScript? In JavaScript, we use document.write() to display an output, BUT in ASP, we use Response.Write() for the same purpose

- To concatenate join several (text|codes), we use plus (+) symbol


<%/* 2 lines of codes below, show how to display the values on the web page*/Response.Write("Username: " + username + "<br>");Response.Write("Password: " + password);%>


How to redirect from 1 page to another in ASP?- Sometimes, after we have successfully log into web application, we will be

redirected to the menu page (for example) or any other pages- This can be done by using Response.Redirect(“<url_or_file>”)- “<url_or_file>” can be URL (website address) or ASP files


<%if(Request.Form("Login") == "Login"){

Response.Redirect("http://www.google.com/");}%><%if(Request.Form("Login") == "Login"){

Response.Redirect("menu_administrator.asp");}%>

Introduction to Server-Side ScriptingJavaScript vs VBScript

JavaScript VBScript

Case-sensitive Not case-sensitive

Able to be executed on any web browsers

Some web browsers may have problems execute VBScript

<%@LANGUAGE=“JavaScript”%> <%@LANGUAGE=“VBScript”%>

JavaScript is open protocol VBScript is not

More complex Less complex

More powerful than VBScript Less powerful than JavaScript


Scripting Language: programming language that allows control of one or more software applications

JavaScript VBScript Hypertext Preprocessor: PHP

Other Server Scripting Language

Outline

Adding server-side scripts into a web page- Inline or intersperse

Using ASP Response.Write to display text on a web page

Server-Side Scripting

Outline

The Response Object The Request Object The Session Object

Build-in ASP Objects

Outline

The Application & Server Objects Using Form Object

Build-in ASP Objects

Outline

Introduction to ADO Accessing data with ADO

Accessing Database with ASP and ADO


Response.Redirect(), Response.Write(), Request.Form() You have seen those three ‘things’ in the previous slides What are they? They are called ASP Objects We have:

- ASP Response Object- ASP Request Object- ASP Server Object- And few others

ASP Objects

Introduction to Server-Side ScriptingASP Response Objects

Property Description

Buffer Specifies whether to buffer the page output or not

CacheControl Sets whether a proxy server can cache the output generated by ASP or not

Charset Appends the name of a character-set to the content-type header in the Response object

ContentType Sets the HTTP content type for the Response object

Expires Sets how long (in minutes) a page will be cached on a browser before it expires

ExpiresAbsolute Sets a date and time when a page cached on a browser will expire



IsClientConnected Indicates if the client has disconnected from the server

Pics Appends a value to the PICS label response header

Status Specifies the value of the status line returned by the server


Method Description

AddHeader Adds a new HTTP header and a value to the HTTP response

AppendToLog Adds a string to the end of the server log entry

BinaryWrite Writes data directly to the output without any character conversion

Clear Clears any buffered HTML output

End Stops processing a script, and returns the current result

Flush Sends buffered HTML output immediately


Method Description

* Redirect Redirects the user to a different URL

* Write Writes a specified string to the output

ASP Response Objects

Collection Description

Cookies Sets a cookie value. If the cookie does not exist, it will be created, and take the value that is specified

Introduction to Server-Side ScriptingASP Request Objects

Collection Description

ClientCertificate Contains all the field values stored in the client certificate

Cookies Contains all the cookie values sent in a HTTP request

* Form Contains all the form (input) values from a form that uses the post method

* QueryString Contains all the variable values in a HTTP query string

ServerVariables Contains all the server variable values



TotalBytes Returns the total number of bytes the client sent in the body of the request

ASP Request Objects

Method Description

BinaryRead Retrieves the data sent to the server from the client as part of a post request and stores it in a safe array

Introduction to Server-Side ScriptingASP Server Objects

Method Description

* CreateObject Creates an instance of an object

* Execute Executes an ASP file from inside another ASP file

GetLastError Returns an ASPError object that describes the error condition that occurred

HTMLEncode Applies HTML encoding to a specified string

* MapPath Maps a specified path to a physical path


Method Description

Transfer Sends (transfers) all the information created in one ASP file to a second ASP file

URLEncode Applies URL encoding rules to a specified string

ASP Server Objects


ScriptTimeOut Sets or returns the maximum number of seconds a script can run before it is terminated

Question?

Knuckles (2001). Introduction to Interactive Programming on the Internet using HTML & Javascript. John Wiley & Sons, Inc.

http://www.w3schools.com/asp/default.asp

Bibliography (Book)

Bibliography (Website)

http://www.w3schools.com/asp/default.asp

csc317 – internet programming csc318 – dynamic web application development

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