Creating Your First Page
with ASP
Active Server Pages is a very powerful and yet
easy-to-learn server-side scripting environment. Active Server Pages comes with
Internet Information Server for Windows NT Server, and with Personal Web Server
for Windows NT Workstation and Windows 98. This environment enables you to
create a Web site that is dynamic, fast, and interactive without requiring you
to worry about the capabilities of your clients' browsers, which you must do if
you rely on client-side scripting like client-side JavaScript or client-side
Visual Basic Script (VBScript).
In this hour, you will learn the following tasks:
What You Need to Run ASP
ASP is available on multiple platforms. With all
Microsoft platforms presented in this hour, I recommend you use at least
Microsoft Personal Web Server (PWS) for Windows NT Workstation to develop
Active Server Pages applications because of its superior functionality over PWS
for Windows 98. However, to use all features--such as the full-text search in
the ASP documentation--you should install Microsoft Internet Information Server
(IIS) version 4.0 on Windows NT Server for development.
If you have only a small computer available for
development, and Windows NT Server is out of reach, you can take your first
steps in the world of ASP using the PWS for Windows 98 or Windows NT
Workstation.
Personal Web Server (PWS)
Personal Web Server (PWS)is a Web server that was
developed for companies or individuals who need a down-scaled IIS for intranet
applications or development. Unlike IIS, a PWS can host only one Web site. PWS'
advantage is that it can be run on an inexpensive Windows 95, Windows 98, or
Windows NT Workstation operating system.
Installing PWS on Windows
98
For certain purposes, you might want to install PWS on
Windows 98 if it is the only operating system available to you, or you want to
take the first steps in ASP programming. To install PWS on Windows 98, you only
need the Windows 98 operating system CD because PWS is contained on this CD.
NOTE:
If you want to install PWS on a Windows 95 computer, you must
install it from the Windows NT 4.0 Option Pack, which also includes a Windows
95 version of PWS.
If you already have installed Windows 98 on your
computer, proceed as follows to install PWS on your Windows 98 operating
system.
To Do: Install PWS on
Windows 98
1. Put
the Windows 98 CD in your CD-ROM drive.
2. Click
the Start button and choose Run.
3. In
the Run dialog box, type X:\add-ons\pws\setup.exe in
the Run input field. Substitute the letter of your CD drive for X, and click OK.
4. The
Personal Web Server Setup window appears (see Figure 1.1). Click Next.
FIGURE 1.1 The Personal Web Server
Setup window.
5. Click
the Custom button in the configuration menu (see Figure 1.2).
FIGURE 1.2 Personal Web Server Setup
options.
6. Add
the ADO documentation (about database access): Double-click Microsoft Data
Access Components, and in the active window on MDAC: ADO, ODBC, and OLE DB.
Then check the ADO documentation to be installed (see Figure 1.3).
FIGURE 1.3 Add a checkmark next to ADO
Documentation in setup.
7. Click
OK to close the window and OK in the second window to close it as well. It is
recommended for development to install ADO documentation because you will need
the documentation to develop database-driven ASP pages.
8. Then
add the Active Server Pages documentation. To do so, double-click Personal Web
Server (PWS), and double-click Documentation. Checkmark Active Server Pages in
the window that appears (see Figure 1.4).
FIGURE 1.4 Checkmark Active Server
Pages Documentation in Setup.
9. Close
the two windows by clicking OK.
10.
Click Next in the PWS Setup Window.
11.
Notice the default Web publishing home directory, X:\Inetpub\wwwroot, where X: is
a drive letter. Click Next to accept the default value (when you change it,
remember that all procedures in this book refer to the default location).
12.
Leave the Microsoft Transaction Server (MTS) install folder to its default
value, and click the Next button.
13. The
PWS setup is completing the installation. When the installation is finished,
you can end setup with a click on the Finish button.
14.
Restart the computer now to be able to use PWS.
After restart, you can use the PWS. Start the PWS, where
you can control it using Start, Programs, Microsoft Personal Web Server,
Personal Web Manager. In the left frame, you see the icons for the five
available areas that appear in the right frame (see Figure 1.5).
FIGURE 1.5 The main section of
Personal Web Manager.
FIGURE 1.6 The Personal Web Manager
Publishing Wizard.
FIGURE 1.7 The Personal Web Manager
Home Page Wizard.
FIGURE 1.8 The Personal Web Manager
Product Tour.
FIGURE 1.9 The Personal Web Manager
advanced options.
A virtual directory is a directory that doesn't
have to be located within your home directory; in fact, it could reside on
another disk or computer, but it can be accessed by a client browser through
the Internet as if it were located within your home directory. For further details,
see the section "Creating Virtual Directories" in Hour 2,
"Introducing Internet Information Server."
Installing PWS on Windows
NT Workstation 4.0
It is necessary to apply Service Pack 3 (or higher) for
Windows NT to your workstation and install Microsoft Internet Explorer (IE)
4.01 (or higher) first before you can install PWS.
NOTE:
IE 4.01 is the minimum requirement; however, you will learn
features in this book that are available only in IE 5.0. Therefore, it is
strongly recommended that you install IE 5.0.
PWS is included in the Windows NT 4.0 Option Pack.
Therefore, you must install the Option Pack to get PWS on your workstation.
NOTE:
You can download Windows NT 4.0 Option Pack from Microsoft's Web
site. The Web address for download is http://www.microsoft.com/ntserver/nts/_downloads/recommended/NT4OptPk/default.asp
(that's 4O, not four zero in the address).
Be sure to also install the Internet Service Manager
(ISM) by performing the following Windows NT 4.0 Option Pack setup steps:
1. Start
Windows NT Option Pack setup.
2. Click
the Custom button in the configuration menu (refer to Figure 1.2).
3. Add
the Internet Service Manager: Double-click the Personal Web Server (PWS)
component and checkmark Internet Service Manager (see Figure 1.10).
FIGURE 1.10 Subcomponents of
PWS--Internet Service Manager.
TIP:
To install the Internet Service Manager (ISM) is some good
advice to take to become familiar with this tool. If you decide to work with
IIS under Windows NT Server, the ISM is necessary for Web server
administration. Also you cannot use Microsoft Script Debugger to find errors in
your script if you have not installed ISM.
It is also useful to install the whole Online Documentation subcomponent of PWS
and the whole Microsoft Data Access Components 1.5. This will make it easier
for you to get answers to questions that are raised during work.
4. All
other setup settings might be left to their defaults. Click the Next button.
5. You
will see the folders of the Web publishing home directory and the Application
Installation Point (see Figure 1.11).
FIGURE 1.11 Web publishing home
directory and Application Installation Point _folders default setup.
6. Click
Next, and you will see the MTS install folder. Click the Next button.
7. Configure
the administrative Account as local and click the Next button.
8. Windows
NT 4.0 Option Pack Setup is completing installation.
9. Click
the Finish button and restart your computer to use PWS.
10.
ISM, the administrative interface of PWS, can be found using Start, Programs,
Windows NT 4.0 Option Pack, Microsoft Personal Web Server, Internet Service
Manager.
NOTE:
It is recommended to install Windows NT Service Pack 4 after
installing PWS. You can download Service Pack 4 from Windows NT from the
Microsoft Web site at http://www.microsoft.com/support/winnt/default.htm.
Keep in mind that you must reapply Service Pack 4 after you install new
features from Windows NT operating system or from Windows NT 4.0 Option Pack.
Internet Service Manager
(ISM) is the name for the IIS administration tool. ISM on Windows NT is
available in the form of an IIS snap-in to the Microsoft Management Console.
The Microsoft Management Console (MMC) is a
common management console that provides a consistent framework that can be used
for all network administration programs, like the IIS or the MTS. A screenshot
of the MMC with the IIS snap-in is provided in Figure 1.12. Because you can
manage Internet services like PWS or IIS from the MMC, it is often referred to
as Internet Service Manager.
FIGURE 1.12 MMC with the IIS snap-in
opened.
NOTE:
For the difference between PWS for Windows NT Workstation and
PWS for Windows 95/98, refer to Hour 2.
In Windows NT Workstation, the MMC with the IIS snap-in
can be accessed through Start, Programs, Windows NT 4.0 Option Pack, Microsoft
Personal Web Server, Internet Service Manager if installed. You can configure
your Web site more precisely with MMC than it would be possible using Personal
Web Manager.
Microsoft Transaction Server, or
MTS, is a transaction processing system for building, administering, and
deploying robust Internet server applications. A transaction is a set of
processes that must be executed either all or none. For example, if you pay
with your credit card, there are two processes:
Either both processes or none of these processes must be
executed, or there would be a magic money increase or decrease.
Internet Information Server
Microsoft Internet Information Server (IIS) is a Web
server that integrates into the Windows NT Server. IIS allows you to publish
information on the Web and to run multiple business applications using ASP.
Installing IIS on Windows NT
Server 4.0
Make sure to have Service Pack 3 (or higher) and Windows
Internet Explorer 4.01 (or higher) installed on your Windows NT Server before
you install the Option Pack. It is recommended to install Internet Explorer 5
instead of 4.
Similar to PWS on Windows NT Workstation, IIS 4.0 is
contained in the Windows NT 4.0 Option Pack. Therefore, you must install the
Option Pack to run IIS 4.0. IIS is administered using the ISM, which is in fact
the IIS snap-in running in the MMC framework.
I recommend developing and testing your ASP site using
IIS on a Windows NT server. IIS provides the Microsoft Index Server, which is
also needed to allow a full text search in the Windows NT Option Pack
documentation that includes IIS and ASP documentation. Therefore, you are able
to find information on a certain topic much faster without knowing the full
structure of the Option Pack documentation.
Microsoft Index Server indexes the contents
and properties of documents. In addition to indexing Web pages, it also indexes
Microsoft Word or Excel documents. Using the capabilities of Microsoft Index
Server, you can provide a full-text search for areas of your Web site running
on an IIS. To install IIS, start Windows NT 4.0 Option Pack setup. Make sure
you install Script Debugger and all needed online documentation.
I recommend applying Service Pack 4 for Windows NT after
installing IIS. You must reapply Service Pack 4 to your computer when you
install a new component of the Windows NT operating system or the Windows NT
4.0 Option Pack.
Write a Little ASP Example
You bought this book because you already mastered HTML
page development and want to make the pages more dynamic with database binding
and more. This is why you are learning Active Server Pages. ASP pages are
nothing more than HTML files interspersed with server-side script code. An ASP
file has an .asp extension instead of .htm or .html
to denote server-side code to the hosting Web server. Because an ASP file is a
text file with the extension .asp that contains a combination of text, HTML
tags, and ASP script commands, you can use every text editor to create or
change an ASP file.
It is time to practice. Open Notepad or another text
editor, and type the lines from Listing 1.1. Do not type the line numbers! Type
Output:<BR>
instead of 3: Output:<BR>.
Line numbers are used to reference the lines of the code during explanation of
the script.
LISTING 1.1 A
SIMPLE ASP FILE THAT COMPUTES THE NUMBER OF SECONDS IN AN HOUR AND RETURNS THE
RESULT TO THE CLIENT
1:
<HTML>
2:
<BODY>
3:
Output:<BR>
4: <%
5: intS = 60*60
6: %>
7: There
are
8: <%
9: Response.Write intS
10: %>
11: seconds in an hour.
12: </BODY>
13: </HTML>
Save Listing 1.1 as asp24h.asp in the home directory of the default Web
site that was installed with PWS or IIS. The path of the home directory is X:\InetPub\wwwroot, where X is the
operating systems hard disk in a default installation.
Congratulations! You have written an ASP file yourself
and deployed it on the server by saving it in the Web server's home directory.
You can access the ASP page asp24h.asp by opening the following
URL in your Web browser:
http://localhost/asp24h.asp
The result of the processed ASP page asp24h.asp appears
as follows:
Output:
There are 3600 seconds in an hour.
Take a closer look at the ASP file in Listing 1.1. In
lines 1 and 2, there are _common HTML tags. The third line consists of text and
an HTML tag.
Output:<BR>
Line 4 includes the characters <%, which indicates the
beginning of a server-side script block. The whole script block is
<%
intS = 60*60
%>
The <% and
%>
characters, called delimiters, enclose server-side script commands of the
default scripting language, which is Visual Basic Script (VBScript) unless you
changed the settings of IIS.
Line 5 is a statement that assigns the value of the
multiplication 60*60 to
the variable intS.
intS = 60*60
Line 6 closes the script block.
Another line of text follows in line 7.
There are
The last script block in lines 9-11 write the content of
the variable strS to the browser.
<%
Response.Write intS
%>
The final line of text follows in line 11.
seconds in an hour.
As you can see now, an ASP page is an HTML page extended
by ASP statements. The ASP statements also control the appearance of text and
HTML tags outside the script blocks, which are just performed in the program
flow of the server-side script. ASP controls the appearance of the Web page
with every call of the ASP file.
You can call the default Web site of your PWS or IIS
using an address like http://localhost/
when the browser is running on the same machine as the PWS or IIS. You can also
use an address like http://IP-Address,
where IP_Address is
the Internet Protocol address of the computer that is running PWS or IIS. Note
that one or more Internet Protocol (IP) addresses are assigned to each Web site
and the IP addresses also must be assigned to the network adapter of the
computer hosting the Web sites.
The unique IP (Internet Protocol) address
identifies a node (such as a workstation or a server) in a network. It is also
used to specify routing information from one network or subnet to another
network or subnet. You can also use domain names in the Internet instead of IP
addresses when calling a Web page. This is made possible through Domain Name
System Server, which provides the correct IP address for a given domain name.
In most of the figures in this book, the domain name www.asp24h.com is used instead of an IP
address like 127.0.0.1.
You cannot use the domain name www.asp24h.com to
run the examples in this book unless you have installed and configured WINS
(Windows Internet Naming Service) or DNS (domain name service). Use the domain localhost or
its IP address 127.0.0.1
instead when you are using a browser that is running on the same computer as
PWS or IIS.
Handling an ASP File
You can edit an ASP file with every text editor as long
as you save it like a text file with the .asp extension instead of .txt. There
are also several software products available that support developing ASP
applications. More about ASP development software is presented in Hour 3,
"Working with ASP."
The Browser's Result of a
Computed ASP File
How is the magic of an ASP file done? You will examine
the processing of an ASP file, from its storage on the hard disk, to being
handled in IIS, to sending the HTML result to the browser.
The basic information to take away from this section is
that processed ASP pages are plain HTML after the Web server has finished
processing the ASP page. See Figure 1.13 for a schematic overview of how this
processing is done.
FIGURE 1.13 Processing of an Active
Server Page request.
The following list walks you, step-by-step, through what
happens if the client requests the page xyz.asp:
1. The
client requests the page xyz.asp from the server. The
Web server checks the file extension to see whether a special program (such as
the Active Server Pages engine) must be invoked to process the request. If
there's an .asp extension, the Web server determines that it should invoke ASP
to process this page.
2. If
this page has never been requested before or has been changed since the last
request, it must be parsed and the syntax checked and compiled by the Web
server. Otherwise, the page might be read from a cache of recently processed
pages, which aids in performance. During the parsing process, the HTML and
scripting code are separated. IIS determines which scripting engine is
responsible for which part of the script and delegates the work of syntax
checking and compiling to the proper scripting engine (such as VBScript).
3. Now
the code is executed by the scripting engine using resources from IIS, which is
hosting the scripting engines. All objects that the language engine cannot
handle are requested from IIS, which is also responsible for handling inputs
and outputs for external ActiveX objects that are created and used inside the
script. If it is not able to supply the object, an error is generated.
4. Script
output and static HTML code in the ASP file are merged.
5. The
final HTML is sent back to the user in an HTTP response.
An ActiveX object provides--as every component
does--reusable code stored in a wrapper, which provides access to the object
through properties, methods, and events. Additionally, the code of the ActiveX
object is running in the same process space as the application that uses it.
ActiveX provides a standard mechanism to extend any programming or scripting
language using the same reusable object. ActiveX Data Objects (ADO) are ActiveX
objects that provide an interface to OLE DB, so you can access nearly any
database through ADO. ADO is the first choice if you want to access a database
from an ASP file.
Summary
In this hour's lessons, you got an overview about how to
install PWS or IIS. You wrote an ASP file, deployed it on the default Web
server, and called it using a Web browser. You also learned a lot of new terms.
The following are the most important terms that will come up, over and over
again, in this book:
Q&A
Q Where can I get Windows
NT 4.0 Option Pack and Service Pack 3 for Windows NT?
A Ask
your local software dealer for Windows NT 4.0 Option Pack and Service Pack 3 or
download the software from Microsoft. Windows NT Service Pack 3 is available at
http://support.microsoft.com/support/downloads/LNP400.asp.
Windows NT 4.0 Option Pack can be obtained on http://www.microsoft.com/ntserver/nts/downloads/recommended/NT4OptPk/default.asp.
Q I want to host more than
one Web site on my Web server. Can I use PWS?
A You
can host only one Web site on PWS. To host multiple Web sites on the same
computer, you have to use Windows NT Server and IIS.
Workshop
The quiz questions and exercises are provided for your
further understanding. See Appendix A, "Answers," for the answers.
Quiz
1. Is
an ASP file processed on the server side (Web server) or on the client side
(Web browser)?
2. Is
any ASP code of an .asp file transmitted from the server to the browser?
3. Which
URL do you call in the browser when you want to access the default Web site?
Exercise
Explore the files in a directory of the default Web site
in PWS or ISM. To explore directories in PWS, you must view the Advanced Option
section, select a directory, right-click it and select Explore. To explore
directories using ISM, double-click the Internet Information snap-in and the
icon of your computer. Then you can browse a directory simply by opening it.