Transcript Document

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 Architectures
What 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.
3
Web-Based Client/Server Applications
Flowchart of a Sample Web-based, three-tiered
Client/Server architecture
Web
Server
Web
Browser
IISApachi
Data
Server
Access-SQL
ServerOracle
Transaction
Internet
Internet
Explorer
Netscape
server
Application
Servers
Database
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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 HTML
ASP = 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 = 15
variable_2 = “15”
variable_3 = true
If you want to learn type of any variable;
<% variable_1 = 15
Response.write vartype(variable_1) ‘it writes 2 to the page
%>
List of Variant type variables of the VBScript
vbNull 1 contains no data, vbInteger 2 integer type, vbLong 3 .....
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VBScript Looping – flow controls
Looping 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
operators
Conditional 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.
2.
3.
4.
Open notpad
Create the necessary HTML codes.
Add ASP codes into their respective places.
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.
OR
Write asp extension with the
file name.
Select Active Server Pages
option as file type. So, you do
not need to write file extension.
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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>” %>
html
Tuna
<B>Tuna</B>
<font size = “2”>Tuna</font>
Tuna
Tuna
response.write “<font size = “2”>Tuna</font>“
typeMismatch
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response.write
response.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 = 40
num2 = 30
response.write num1 + num2
%>
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response.write
Example 2:finding y
<%
a=1
b=5
c=2
y= b*b - 4*a*c
response.write y
%>
Example 3:finding the square of 2 numbers
and the addition of their square
<%
num1 = 10
num2 = 20
sq1 = num1 * num1
sq2 = num2 * num2
sum = num1 + num2
response.write sq2 &","& sq1 & "," & sum
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response.write & if..then..else..end if
Example 4:VAT included Price
<%
VAT = 18
PRICE = 3000000
VAT_INC = PRICE + (PRICE * VAT)/100
Response.Write "VAT included price is"& " " & VAT_INC
%>
Example 5:positive or negative?
<%
num = 89
IF num >0 THEN
response.write num &" "& "is a positive number.“
ELSE
response.write num &" "& "is a negative number.“
END IF
%>
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response.write & if..then..else..end if
Example 6: If a number less than 10, output it's square
otherwise the number only.
<% num = 9
IF num > 10 THEN
sq = num * num
response.write sq
ELSE
response.write num
END IF %>
Example 7: Subtract the smaller from the larger
<% num1 = 3
num2 = 5
IF num1>num2 THEN
num = num1 - num2
ELSE
num = num2 - num1
END IF
Response.Write num %>
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response.write & if..then..else..end if
Example 8: SNG room 100$ others 150$>
<% room_type = "DBL“
num_of_night = 10
IF room_type = "SNG" THEN
price = 100 * num_of_night
ELSE
price = 150 * num_of_night
END IF
Response.Write "room price is " & price %>
Example 9: PASS, FAIL
<%
final = 50
IF final >= 50 THEN
Response.Write "PASS“
ELSE
Response.Write "FAIL“
END IF
%>
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