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Today: Introduction to ASP- Part 1

• Explain the client/server architecture

• Explain Web-based client/server applications

• Understand the essentials of Active Server Pages

• Write and edit simple ASP files.

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Client/Server ArchitecturesWhat is Client/Server Architecture?

Client/Server Architecture is the structural design of a computer network.

Components;

- Clients, or client computers and their software- Servers, which include hardware and software

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Client/Server Architectures

A typical Client/Server Relationship

- Users at the client computers send service requests to a server computer

- The server computer process the requests sends the results back to the client computers.

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Web-Based Client/Server Applications

Flowchart of a Sample Web-based, three-tiered Client/Server architecture

Internet Explorer

-Netscape

Transaction

server

Application

Servers

Data Server

Web Server

IIS- Apachi

Access-SQL Server- Oracle

Database

Internet

Web Browser

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Active Server Pages

Active Server Pages (ASPs) are Web pages

ASP = server-side scripts + HTML

The appearance of an Active Server Page depends on who or what is viewing it.

• If the Web browser that receives it, an Active Server Page looks just like a normal HTML page.

• However, the file located in the server looks very different. In addition to text and HTML tags, you also see server-side scripts.

This is what the Active Server Page looks like to the Web server before it is processed and sent in response to a request.

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How ASP Works?

1. User brings up a Web site where the default page has the

extension .asp.

2. The browser requests the ASP file from the Web server

3. The server-side scripts begins to run with ASP.

4. ASP processes the requested file sequentially (top-down),

executes any script command contained in the file, and produces

an HTML Web page.

5. The Web page is sent to the browser.

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ASP vs HTMLASP = HTML + some other stuff!

What is the difference? Basically we are taking the HTML and adding some elements...

• ASP files end with the .asp extension, so the Web server knows what it is.

• ASP files include server-side code that contain instructions for the server.

• Browser can not display your code!

• ASP files provide dynamic information

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Active Server Pages

Server-side scripts ~ HTML tags.

<%...%> ~ <...>

You can insert server-side scripts anywhere in your Web page--

even inside HTML tags.

<h1> <% = “Hello World” %> </h1>

The server looks inside the ASP tags and runs the instructions, sends the

results

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Variables

Every application uses variables, and ASP scripts are no exception!

But there is no obligation in Visual Basic and VbScript

No need to define the variables and variable types at the beginning of the program. But if you want you can...

If you add the following line after the language info to the page;

<% Option Explicit %> You must declare your variables. i.e. dim number1

dim number2

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Variables

Basic Variable Types: numeric, alpha-numeric, and logical.

No need to know other variable types, because when you assign a value to a variable, Visual Basic understands your variable type!variable_1 = 15variable_2 = “15”variable_3 = true

If you want to learn type of any variable;

<% variable_1 = 15Response.write vartype(variable_1) ‘it writes 2 to the page%>

List of Variant type variables of the VBScriptvbNull 1 contains no data, vbInteger 2 integer type, vbLong 3 .....

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VBScript Looping – flow controlsLooping constructs provide the foundation for any application that must repetitively perform a task.Such as adding 1 to a variable, reading a text file, or processing an e-mail message.VBScript and Jscript provide several looping mechanism. For... Next, For each ... in ...Next, Do.. Loop While, Do...While...Loop, Do..Until...Loop, Do...Loop Until..., While ...Wend

conditional operatorsConditional operators, together with variables and looping constructs, for the fundamental building blocks of applications.Such as sending a page to the client browser that consists of the current time and date and a greeting

If..Then, If...then...else, If...then...Elseif...then else, Select...Case, Switch..case

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How to Create ASP Pages?

1. Open notpad2. Create the necessary HTML codes.3. Add ASP codes into their respective places.4. Save your file with the extension .asp.

1. Design the followings in FrontPage:

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How to Create ASP Pages ?

2. Switch to HTML tab.

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How to Create ASP Pages?3. Add ASP codes into their respective places.

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Reponse.Write ( )

Response object is the part of ASP that handles responding to the request of a browser

If you want to display information to Web page Write method of the response object will be used.

<%Response.Write(“Hello World”)%>

NOTE : equal sign (=) is a short-cut of response.write object

<% = “Hello World” %>

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How to Save ASP Pages?

4. Save your file with the extension .asp.

Write asp extension with the file name.

Select Active Server Pages option as file type. So, you do not need to write file extension.

OR

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How to transfer to the Server?

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How to Display ASP Pages?

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Another example! (“for – next”)

We want to write “hosgeldiniz” in 5 different font size!

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Handling HTML codes in ASP codes

<% response.write “ “ & “ “ & i%>

<% Response.write “<BR>” %>

htmlTuna Tuna<B>Tuna</B> Tuna<font size = “2”>Tuna</font> response.write “<font size = “2”>Tuna</font>“

typeMismatch

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response.writeresponse.write “<font size = “2”>Tuna</font>“

Handling Error:1st way: Do not use “ “ in HTML! But;

<font face = lucida handwriting> face = lucida?

<%response.write<table width = 100%>%> ?

2nd way: use ‘ ‘ instead of “ “

Examples:Example 1:Adding 2 numbers<%num1 = 40num2 = 30response.write num1 + num2%>

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response.writeExample 2:finding y

<% a=1b=5c=2y= b*b - 4*a*cresponse.write y%>

<%num1 = 10num2 = 20sq1 = num1 * num1sq2 = num2 * num2sum = num1 + num2response.write sq2 &","& sq1 & "," & sum

Example 3:finding the square of 2 numbers and the addition of their square

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response.write & if..then..else..end ifExample 4:VAT included Price

<%VAT = 18PRICE = 3000000VAT_INC = PRICE + (PRICE * VAT)/100Response.Write "VAT included price is"& " " & VAT_INC%>

<%num = 89IF num >0 THEN

response.write num &" "& "is a positive number.“ELSE

response.write num &" "& "is a negative number.“END IF%>

Example 5:positive or negative?

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response.write & if..then..else..end ifExample 6: If a number less than 10, output it's square otherwise the number only.<% num = 9IF num > 10 THEN

sq = num * numresponse.write sq

ELSEresponse.write num

END IF %>

<% num1 = 3num2 = 5IF num1>num2 THEN

num = num1 - num2ELSE

num = num2 - num1END IF Response.Write num %>

Example 7: Subtract the smaller from the larger

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response.write & if..then..else..end ifExample 8: SNG room 100$ others 150$>

<% room_type = "DBL“num_of_night = 10IF room_type = "SNG" THEN

price = 100 * num_of_night ELSE

price = 150 * num_of_nightEND IFResponse.Write "room price is " & price %>

Example 9: PASS, FAIL

<% final = 50IF final >= 50 THEN

Response.Write "PASS“ELSE

Response.Write "FAIL“END IF%>