1. Chapter 33 - Active Server Pages (ASP)
Outline
Introduction
How Active Server Pages Work
Setup
Active Server Page Objects
Simple ASP Examples
File System Objects
Session Tracking and Cookies
33.8 ActiveX Data Objects (ADO)
Accessing a Database from an Active Server Page
Server-Side ActiveX Components
Web Resources

2. In this tutorial, you will learn:
Objectives
In this tutorial, you will learn:
To program Active Server Pages using VBScript.
To understand how Active Server Pages work.
To understand the differences between client-side scripting and server-side scripting.
To be able to pass data between Web pages.
To be able to use server-side include statements.
To be able to use server-side ActiveX components.
To be able to create sessions.
To be able to use cookies.
To be able to use ActiveX Data Objects (ADO) to access a database.

3. Server-side technologies
33.1 Introduction
Server-side technologies
Dynamically creates Web pages
Use client information, server information and information from the Internet
Active Server Pages (ASP)
Microsoft Server-side technology
Dynamically build documents in response to client requests
Deliver dynamic Web content
XHTML, DHTML, ActiveX controls, client-side scripts and Java applets

4. 33.2 How Active Server Pages Work
Processed by scripting engine
Server-side ActiveX control
.asp file extension
Can contain XHTML tags
Scripting written with VBScript
JavaScript also used
Others (Independent Software Vendors)
Communication with Server
Client HTTP request to server
Active server page processes request and returns results

5. 33.2 How Active Server Pages Work
Active Server Pages,cont.
Communication with Server, cont.
ASP document is loaded into memory
asp.dll scripting engine on server
Parses (top to bottom)

6. 33.3 Setup
Web Server
Need to run Web server to use Active Server Pages
IIS 5.0 (Internet Information Services) or higher
Create a virtual directory
Copy files to c:\InetPub\Wwwroot

7. 33.4 Active Server Page Objects
Built-in objects
Communicate with a Web browser
Gather data sent by HTTP request
Distinguish between users
Request
Get or post information
Data provided by the user in an XHTML form
Access to information stored on client machine
Cookies
File upload (binary)
Response
Sends information to client
XHTML, text
Server
Access to server methods or properties

8. 33.4 Active Server Page Objects

9. 33.5 Simple ASP Examples ASP Scripts Scripting delimiters
<% %>
@LANGUAGE directive
Option Explicit
As in VBScript, forces all variables to be declared in advance
FormatDateTime
Time to display
Now
Format to display in

10. Scripting delimiter wraps around code executed on the server.
Processing directive specifying scripting language
clock.asp (1 of 2)
Requires programmer explicitly define all variables

11. Returns server date and time (Now) as a string formatted in vbLongDate format
“<%=“ is short for Response.write
clock.asp (2 of 2)
Statement is short for: <% Call Response.write( Time()) %>

12. 33.5 Simple ASP Examples
Fig Simple Active Server Page.

13. HTML generated by clock.asp (1 of 2)

14. HTML generated by clock.asp (2 of 2)

15. 33.5 Simple ASP Examples ASP processes input
Form information sent by client
E-commerce Web site
Use to verify customer information
Server responds to process request
Form
Using post method
action attribute indicates the .asp file to which the form information is posted
Request object retrieves form data

16. name.html (1 of 2)

17. action set to ASP file where information is posted.
name.html (2 of 2)

18. 33.5 Simple ASP Examples
Fig XHTML document that requests an ASP.

19. name.asp (1 of 2)

20. name.asp (2 of 2)
Request object retrieves form data from text field “namebox”

21. 33.5 Simple ASP Examples
Fig ASP document that responds to a client request.

22. File System Objects (FSOs)
Allow programmer to manipulate files, directories and drives
Read and write text
Microsoft Scripting Runtime Library (Fig 33.6)
FileSystemObject, File, Folder, Drive and TextStream
Use to create directories, move files, determine whether a Drive exists
FileSystemObject methods (Fig. 33.7)
File object
Allows programmer to gather info about files, manipulate files, open files
File properties and methods (Fig. 33.8)

23. 33.6 File System Objects

24. 33.6 File System Objects

25. 33.6 File System Objects

26. 33.6 File System Objects

27. File System Objects (FSOs)
Path property
Contains File path in long name format
ShortName property
Contains File path in short name format
Folder object
Allows programmer to manipulate and gather info about directories
Folder properties (Fig. 33.9)

28. 33.6 File System Objects

29. 33.6 File System Objects

30. File System Objects (FSOs)
IsRootFolder property
Indicates whether folder is the root folder for the Drive
If not:
Method ParentFolder
Retrieves parent folder
Method Size
Returns the total bytes the folder contains (includes subfolders)

31. File System Objects (FSOs)
Drive object (Fig )
Gather information about drives
Property DriveLetter
Contains drive letter
Property SerialNumber
Contains drive serial number
Property FreeSpace
Contains number of available bytes

32. 33.6 File System Objects

33. File System Objects (FSOs)
TextStream object (Fig )
Manipulate text files

34. 33.6 File System Objects

35. 33.6 File System Objects

36. 33.6 File System Objects Creating a guestbook XHTML Form
hidden field
Determine if page loaded by form submission
Write data to text file
ServerVariables
APPL_PHYSICAL_PATH
OpenTextFile
Append mode 8

37. Creating a guestbook, cont.
33.6 File System Objects
Creating a guestbook, cont.
Name returned as mailto: URL
Request object
Chr function
Generate characters from ASCII code
Always Close files

38. guestbook.asp (1 of 5)

39. Concatenated with file name guestbook.txt
Set is required to establish a variable in VBScript
Pass Request method ServerVariables server key APPL_PHYSICAL_PATH
guestbook.asp (2 of 5)
Creating a FSO instance assigned to reference fileObject
Request object retrieves hiddenInput value and tests it against string “true”
Prints string followed by users name input in the form
Submitted name and are combined and assigned to string mailtoUrl
Pass value 34 into VBScript Chr function to produce double quotes (“”)
Displays a mailto: link.
Date() assigns current server date to beginning of mailtoUrl
Request retrieves “ ” and “username”

40. Contstant 8 indicates append mode (writing to the end of the file.)
guestbook.asp (3 of 5)
Method OpenTextFile retrieves TextStream object for accessing file guestbook.txt
Contstant 8 indicates append mode (writing to the end of the file.)
TextStream method WriteLine writes to guestbook.txt
Close() method closes the file
Form post action to .asp page

41. Form contains two text fields and text area for user input
guestbook.asp (4 of 5)
Passes parameter hiddenInput value “true”

42. FSO object FileExists checks if guestbook.txt exists.
guestbook.asp (5 of 5)
Response.Write writes text to client. Contains XHTML markup rendered on client browser.
Read entries from guestbook.txt and write XHTML to the client
TextStream and ReadAll methods read entire contents of guestbook.txt

43. 33.6 File System Objects
Fig Guestbook Active Server Page.

44. 33.6 File System Objects
Fig Guestbook Active Server Page.

45. XHTML generated by guestbook.asp (1 of 1)

46. 33.6 File System Objects

47. 33.7 Session Tracking and Cookies
Helps server to distinguish between clients
Provide custom content
Shopping cart
Marketing/advertising
SessionID
Assigned by server to each unique session
Compared with sessionIDs stored in server
Session object
Timeout property
Length of session before it expires
Abandon property
Terminates individual session

48. 33.7 Session Tracking and Cookies
ASP application
Multiple ASP pages linked with session variables
Example
instantpage.asp
Form, requests information from the user
Posted to process.asp
process.asp
Redirects user to instantpage.asp if errors exist
Otherwise creates users ASP page
Stores message in session variable welcomeBack
Every time user submits the form

49. 33.7 Session Tracking and Cookies
Server-side include
Commands embedded in XHTML documents
Add dynamic content
Places a .shtml include file within another file
Physical or virtual path
<!--#include file = “includes\file.shtml” -->
Not all Web servers support
Written as comment
Performed before scripting code is interpreted.
ASP page cannot determine which includes to use
Can contain scripting code
Must use <script> tag or <% %> delimiters

50. instantpage.asp (1 of 4)

51. First time page is executed, line 35 returns true
Server-side include
instantpage.asp (2 of 4)
If statement tests errorMessage equality to “no error”. Return True or False.
Session object retrieves variable value
errorMessage never has a value unless errors are encountered
errorMessage session variable used for error messages
First time page is executed, line 35 returns true
If true, errorMessage value is written to client
Else, WelcomeBack value is written to the client
welcomeBack session variable displays “welcome back” message to returning users
Requests process.asp when form is posted

52. instantpage.asp (3 of 4)

53. instantpage.asp (4 of 4)
Server-side include

54. 33.7 Session Tracking and Cookies
Fig ASP that posts user information to process.asp.

55. 33.7 Session Tracking and Cookies
Fig ASP that posts user information to process.asp.

56. 33.7 Session Tracking and Cookies
Fig ASP that posts user information to process.asp.

57. header.shtml (1 of 1)

58. footer.shtml server-side include file for the document footer

59. Assign message value to session variable errorMessage
process.asp (1 of 6)
If field is empty or contains default string yourfilename, lines assign XHTML error message to variable message.
If statement validates contents of text field.
Assign message value to session variable errorMessage
Server method Transfer requests instantpage.asp

60. Builds fileName by concatenating “filename” to the .asp file extension
FSO object is created if valid user name is entered and assigned reference fileObject
Request.ServerVariables retrieves physical path
Builds fileName by concatenating “filename” to the .asp file extension
process.asp (2 of 6)
Specify server path where ASP file is written
If file exists, variable errorMessage value is set to XHTML containing error message
filePath passed FileExists method. Determines if file exists.
Server.Transfer method requests instantpage.asp

61. process.asp (3 of 6)
Assigns XHTML for “welcome back” message to welcomeBack session variable
Assign ASP scripting delimiters to string variables openMark and closeMark
Construct XHTML for header

62. Form values retrieved using Request object process.asp (4 of 6)
footer variable assigned to XHTML footer contents

63. process.asp (5 of 6)
Lines send XHTML to client that contains link to created page

64. process.asp (6 of 6)

65. aboutme.asp (1 of 2)

66. aboutme.asp (2 of 2)

67. 33.7 Session Tracking and Cookies
Fig Welcome back message displayed by instantpage.asp.

68. 33.7 Session Tracking and Cookies
Fig Error message generated by instantpage.asp.

69. 33.8 ActiveX Data Objects (ADO)
Enables database connectivity
Part of Universal Data Access architecture
OLE DB provides low-level access
ODBC allows C programs to access databases
ADO allows web applications to access databases
Provides pre-built objects for use in ASP and VBScript
Collections

70. 33.8 ActiveX Data Objects (ADO)
Fig Microsoft’s UDA architecture.
ADO
OLE DB
Legacy data
Relational data sources
Application or Browser
Non-relational data sources
ODBC

71. 33.8 ActiveX Data Objects (ADO)
Fig Portion of the ADO object model.
Connection
Command
Parameters
Parameter
Errors
Error
RecordSet
Fields
Field

72. 33.8 ActiveX Data Objects (ADO)

73. 33.9 Accessing a Database from an Active Server Page
Web applications
Communicating with databases
Use ActiveX Data Objects (ADO)
Provides uniform way for programs to connect with databases
Three-tier distributed applications
User interface
Created with XHTML, DHTML or XML
Contains ActiveX controls, client-side scripts, Java applets
Communicate directly with business logic
Business logic
Database access
May reside on separate computers

74. 33.9 Accessing a Database from an Active Server Page
Web applications, cont.
Three-tier distributed applications, cont.
Web servers build middle tier
Provide business logic
Manipulates databases
Communicates with client Web browsers
ASP communications with databases
Use SQL-based queries
ADO handled specifics
Through OLE DB
Databases provide data source for dynamic content
Allows users who are not familiar with Web languages to create Web pages
Restrict access
Password protection
Query Access database

75. Ignores errors until end of script
database.asp (1 of 2)
Ignores errors until end of script
Server method CreateObject creates ADODB.Connection
When Open finishes executing, points to first record or EOF if no records were found
Declares session variable errorString
Method Open opens database specified by ODBC System DSN (login)
loginData reference is set to an ADODB.recordset object
errorHandlerLog processes errors
Open method is passed string containing SQL query and ADODB.Connection object
errorHandlerLog called again
Sets session variable loginData to variable loginData which references the ADODB.recordset containing all records matching SQL query

76. Error number and message concatenated to variable errorString
If true, errorString variable is assigned XHTML text containing error number and message
Err object Number property contains VBScript error number. Tests if error has occurred.
database.asp (2 of 2)
Error number and message concatenated to variable errorString

77. 33.9 Accessing a Database from an Active Server Page
Fig Error messages sent to login.asp by database.asp.

78. login.asp (1 of 7)
Assigns SQL query to session variable query
Executes database.asp to retrieve login IDs from the database

79. login.asp (2 of 7)
Tests if session variable errorString value is empty string
Lines test is session variable loginFailure is True

80. Requests loginID cookie
login.asp (3 of 7)
select structure builds drop-down list of loginIDs
Requests loginID cookie
Selects the returning user’s login ID option
Build loginID options

81. login.asp (4 of 7)
If false, print error message to user

82. login.asp (5 of 7) Tests for EOF found set to False before loop
If statement tests whether option needs to be selected

83. Once selected is written for an option, found set to true
Determines whether current record’s loginID field is equal to loginID cookie
If statement writes selected for an option
login.asp (6 of 7)
Once selected is written for an option, found set to true

84. Increments the record set pointer to next record
login.asp (7 of 7)
Increments the record set pointer to next record
while loop (lines ) iterates through loginData’s records
Sets option value to current login ID
Writes option display as current login ID

85. 33.9 Accessing a Database from an Active Server Page
Fig ASP document that allows the user to log in to a site.

86. 33.9 Accessing a Database from an Active Server Page
Fig ASP document that allows the user to log in to a site.

87. Checks password against the password in recordset
Check whether password field is empty or id loginID field contains default value
submitlogin.asp (1 of 2)
If so, variable loginFailure set to true, client redirected back to login.asp
Checks password against the password in recordset
WHERE specifies a condition on which records are selected
Executes database.asp to query database
Sets reference loginData to session variable loginData (contains records matching query.)

88. Sets cookie’s expiration date to current date plus 3 days
Sets session variable loginFailure value to False
If true, line writes form’s loginID value as cookie named loginID
submitlogin.asp (2 of 2)
Calls Server method Transfer to redirect client to instantpage.asp
Otherwise loginFailure set to True and client is redirected to login.asp

89. 33.9 Accessing a Database from an Active Server Page
Fig ASP document that validates user login.

90. 33.9 Accessing a Database from an Active Server Page
Fig ASP document that validates user login.

91. 33.9 Accessing a Database from an Active Server Page
Fig Cookies folder before and after cookie creation.

92. 33.10 Server-Side ActiveX Components
ActiveX controls on the server with no GUI
Make features available in ASP
AdRotator ActiveX component
Rotates advertisements on a Web page
Randomly displays one of several advertisements
Minimizes space on a Web page committed to advertisements
Client does not have to support ActiveX technologies (on the server)
PageCounter ActiveX component
Page “hit” counter

93. 33.10 Server-Side ActiveX Components

94. component.asp (1 of 4)

95. Sends advertisement as HTML to client
Sends advertisement as HTML to client. Method GetAdvertisement called using reference rotator. Retrieves advertisements from config.txt
component.asp (2 of 4)
Creates AdRotator component instance, assigns it reference rotator
Obtains information about user’s browser
Check property VBScript value
Test JavaScript property

96. Tests Cookies property to determine if browser supports cookies
BrowserType object’s Browser, Version and MinorVer properties can obtain similar client information
Passes server variable key HTTP_USER_AGENT to ServerVariables, obtains string containing user information
component.asp (3 of 4)
Tests Cookies property to determine if browser supports cookies
Increments number of “hits” by one

97. Returns number of “hits”
component.asp (4 of 4)

98. 33.10 Server-Side ActiveX Components
Fig Demonstrating server-side ActiveX components.

99. 33.10 Server-Side ActiveX Components
Fig Demonstrating server-side ActiveX components.

100. 33.10 Server-Side ActiveX Components
Fig Demonstrating server-side ActiveX components.

101. Header contains REDIRECT file URL
Image URL, destination URL, alt value, image display ratio
Advertisement dimensions
Asterisk separates header from advertisements
config.txt (1 of 1)

102. redirect.asp (1 of 1)