4.2 ASP Basics

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2004 Prentice Hall, Inc. All rights reserved.

1

Active Server Pages (ASP)

Outline

33.1 Introduction

33.2 How Active Server Pages Work

33.3 Setup

33.4 Active Server Page Objects

33.5 Simple ASP Examples

33.6 File System Objects

33.7 Session Tracking and Cookies

33.8 ActiveX Data Objects (ADO)

33.9 Accessing a Database from an Active Server Page

33.10 Server-Side ActiveX Components

33.11 Web Resources

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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.

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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

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Active Server Pages 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

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Active Server Pages,cont. Communication with Server, cont.

ASP document is loaded into memory

asp.dll scripting engine on server

Parses (top to bottom)

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33.3 Setup

Web ServerNeed 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

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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

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Object Name DescriptionRequest Used to access information passed by an HTTP request.

Response Used to control the information sent to the client.

Server Used to access methods and properties on the server.

Fig. 25.1Commonly used ASP objects.

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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

1 LANGUAGE VBS i

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2004 Prentice Hall, Inc.

All rights reserved.

Outline10

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2

3

8

9

11

12

13

14 15 A Simple ASP Example

16

17

18 td { background-color:black;

19 color:yellow }

20 strong { font-family:arial, sans-serif;

21 font-size:14pt; color:blue }

22 p { font-size:14pt }

23

24

25

clock.asp

(1 of 2)

Scripting delimiter

wraps around code

executed on the server.

Processing directive

specifying scripting

languageRequires programmer explicitly

define all variables

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Outline11

26

27

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29

A Simple ASP Example

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39 40

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clock.asp

(2 of 2)

Returns server date and time

(Now) as a string formatted in

vbLongDate format

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Fig. 33.2 Simple Active Server Page.

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Outline13

HTML generated by

clock.asp

(1 of 2)

1

3

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5

6

7A Simple ASP Example

8

9

10 td { background-color: black;

11 color:yellow }

12 strong { font-family:arial, sans-serif;

13 font-size:14pt; color:blue }

14 p { font-size:14pt }15

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17

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19

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Outline14

HTML generated by

clock.asp

(2 of 2)

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22

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25 Thursday, May 24, 2001

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28

29 2:22:58 PM

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33

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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

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Outline16

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10 Name Request

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1415

16 Enter your name:

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name.html

(1 of 2)

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Outline17

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action set to ASP file

where information is

posted.

name.html

(2 of 2)

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Fig. 33.4 XHTML document that requests an ASP.

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2004 Prentice Hall, Inc.All rights reserved.

Outline19

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14 15 Name Information

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18 p { font-family:arial, sans-serif;

19 font-size:14pt; color:navy }

20 .special { font-size:20pt; color:green }

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22

name.asp

(1 of 2)

2023

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Outline20

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27

Hi ,

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Welcome to ASP!

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name.asp

(2 of 2)Request object retrieves

form data from text field

namebox

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Fig. 33.5 ASP document that responds to a client request.

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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 andTextStream

Use to create directories, move files, determine whether a

Drive exists

FileSystemObjectmethods (Fig. 33.7)

File object Allows programmer to gather info about files, manipulate

files, open files

File properties and methods (Fig. 33.8)

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Object type Description

FileSystemObject Allows the programmer to interact with Files, Folders and

Drives.

File Allows the programmer to manipulate Files of any type.

Folder Allows the programmer to manipulate Folders (i.e., directories).

Drive Allows the programmer to gather information about Drives (harddisks, RAM diskscomputer memory used as a substitute for harddisks to allow high-speed file operations, CD-ROMs, etc.). Drivescan be local or remote.

TextStream Allows the programmer to read and write text files.

Fig. 33.6 File System Objects (FSOs).

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Methods Description

CopyFileCopies an existing File.

CopyFolder Copies an existing Folder.

CreateFolder Creates and returns a Folder.

CreateTextFile Creates and returns a text File.

DeleteFile Deletes a File.

DeleteFolder Deletes a Folder.

DriveExists Tests whether or not a Drive exists. Returns a boolean.

FileExists Tests whether or not a File exists. Returns a boolean.

FolderExists Tests whether or not a Folder exists. Returns a boolean.

GetAbsolutePathName Returns the absolute path as a string.

Fig. 33.7 FileSystemObjectmethods. (Part 1 of 2)

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Methods Description

GetDriveReturns the specified Drive.

GetDriveName Returns the Drive drive name.

GetFile Returns the specified File.

GetFileName Returns the File file name.

GetFolder Returns the specified File.

GetParentFolderName Returns a string representing the parent folder name.

GetTempName Creates and returns a string representing a file name.MoveFile Moves a File.

MoveFolder Moves a Folder.

OpenTextFile Opens an existing text File. Returns a TextStream.

Fig. 33.7 FileSystemObjectmethods. (Part 2 of 2)

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Property/method Description

Property

DateCreated Date. The date the File was created.

DateLastAccessed Date. The date the File was last accessed.

DateLastModified Date. The date the File was last modified.

Drive Drive. The Drive where the file is located.

Name String. The File name.

ParentFolder String. The Files parent folder name.

Path String. The Files path.

ShortName String. The Files name expressed as a short name.

Size Variant. The size of the File in bytes.

Method

Copy Copy theFile

. Same asCopyFile

ofFileSystemObject

.

Delete Delete the File. Same as DeleteFile ofFileSystemObject.

Move Move the File. Same as MoveFile ofFileSystemObject.

OpenAsTextStream Opens an existing File as a text File. Returns TextStream.

Fig. 33.8 Some commonFile properties and methods.

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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)

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Properties

Attributes Integer. Value indicating Folders attributes (read only, hidden, etc.).

DateCreated Date. The date the folder was created.

DateLastAccessed Date. The date the folder was last accessed.

DateLastModified Date. The date the folder was last modified.

Drive Drive. The Drive where the folder is located.

IsRootFolder Boolean. Indicates whether or not a Folder is a root folder.

Name String. The Folders name.

ParentFolder Folder. The Folders parent folder.

Path String. The Folders path.

ShortName String. The Folders name expressed as a short name.

ShortPath String. The Folders path expressed as a short path.

Size Variant. The total size in bytes of all subfolders and files.

Type String. The Folder type.

Fig. 33.9 SomeFolderproperties and methods. (Part 1 of 2)

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MethodsDelete Delete the Folder. Same as DeleteFolder of

FileSystemObject.

Move Move the Folder. Same as MoveFolder of

FileSystemObject.

Copy Copy the Folder. Same as CopyFolder of

FileSystemObject.

Fig. 33.9 Some Folder properties and methods. (Part 2 of 2)

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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)

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File System Objects (FSOs) Drive object (Fig. 33.10) Gather information about drives

Property DriveLetter

Contains drive letter

Property SerialNumber

Contains drive serial number

Property FreeSpace

Contains number of available bytes

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Property Description

AvailableSpace Variant. The amount of available Drivespace in bytes.

DriveLetter String. The letter assigned to the Drive(e.g., C).

DriveType Integer. The Drivetype. Constants Unknown, Removable, Fixed,

Remote, CDRom and RamDisk represent Drive types and have thevalues 05, respectively.

FileSystem

String. The file system Drivedescription (FAT, FAT32, NTFS, etc.).FreeSpace Variant. Same as AvailableSpace.

IsReady Boolean. Indicates whether or not a Driveis ready for use.

Path String. The Drives path.

RootFolder Folder object. The Drives root Folder.

SerialNumber Long. The Driveserial number.

TotalSize Variant. The total Drivesize in bytes.VolumeName String. The Drivevolume name.

Fig. 33.10 Drive properties.

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File System Objects (FSOs) TextStream object (Fig. 33.11) Manipulate text files

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Property/Method Description

Properties

AtEndOfLine Boolean. Indicates whether the end of a line has been encountered.

AtEndOfStream Boolean. Indicates whether the end of file has been encountered.

Column Integer. Returns the characters position in a line.

Line Integer. Returns the current line number.

Methods

Read String. Returns a specified number of characters from the file

referenced by the TextStreamobject.

ReadAll String. Returns the entire contents of the file referenced by the

TextStreamobject.

Fig. 33.11 TextStream methods and properties. (Part 1 of 2)

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Property/Method Description

Methods, cont.

ReadLine String. Returns one line from the file referenced by the

TextStreamobject.

Write String. Writes text to the file referenced by the TextStreamobject.

WriteBlankLines String. Writes newline characters to the file referenced by the

TextStreamobject.WriteLine String. Writes one line to the file referenced by the TextStream

object.

Skip Variant. Skips a specified number of characters while reading from thefile referenced by the TextStreamobject.

SkipLine Variant. Skips a line of characters while reading from the file

referenced by the TextStreamobject.

Close Close the file referenced by the TextStreamobject.

Fig. 33.11 TextStream methods and properties. (Part 2 of 2)

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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

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Creating a guestbook, cont.Name returned as mailto: URL

Request object

Chr function

Generate characters from ASCII code

Always Close files

O tli381

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Outline23

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8

10

11

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14 GuestBook Example15

16

17 hr { size:1; color:blue }

18 table { text-align:center }

19 td { font-size:12pt }

20 p { font-size:14pt; color:blue }

21 .font { font-family:arial, sans-serif }

22

23

24

guestbook.asp

(1 of 5)

O tline3925

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Outline26 Dim fileObject, textFile, guestBook, mailtoUrl27

28 ' get physical path for this ASP page and

29 ' concatenate guestbook.txt to it

30 guestbook = Request.ServerVariables( "APPL_PHYSICAL_PATH" ) _

31 & "\guestbook.txt"

32

33 ' instantiate a FileSystemObject

34 Set fileObject = Server.CreateObject( _

35 "Scripting.FileSystemObject" )

36

37 ' Check if this request is after the user has posted the form

38If Request( "hiddenInput" ) = "true"Then

39

40 ' Print a thank you

41 Call Response.Write( "Thanks for your entry, " & _

42 Request( "username" ) & "!" )

43 %>

44

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Outline5152 ' open the guestbook, 8 is for appending

53 ' create the guestbook if it does not exist

54 Set textFile = _

55 fileObject.OpenTextFile( guestbook, 8, True )

56

57 ' write data to guestbook.txt

58 Call textFile.WriteLine( "" & mailtoUrl & _

59 Request( "comment" ) )

60 Call textFile.Close()

61 End If

62 %>

63

64

Please leave a message in our guestbook.

65

66

67

68

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70 Your Name: 71

74

guestbook.asp

(3 of 5)

Method OpenTextFileretrieves TextStream object

for accessing fileguestbook.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

Outline4175

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Outline

guestbook.asp

(4 of 5)

76

77 Your email address:

78

82

83

84

85

86 Tell the world:

87

89 Replace this text with the information

90 you would like to post.

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93

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95 96

98

99

Form contains two

text fields and text

area for user input

Passes parameter

hiddenInput

value true

Outline42100

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Outline101 check if the file exists102 If fileObject.FileExists( guestBook ) = TrueThen

103

104

105 ' open the guestbook, "1" is for reading

106 Set textFile = fileObject.OpenTextFile( guestbook, 1 )

107

108 ' read the entries from the file and write them to

109 ' the client.

110 Call Response.Write( "Guestbook Entries:
" & _

111 textFile.ReadAll() )

112 Call textFile.Close()

113

114 End If

115 %>

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117

118

119

guestbook.asp

(5 of 5)

FSO object FileExists

checks ifguestbook.txt

exists.

Read entries from

guestbook.txt and write

XHTML to the client

TextStream and ReadAll

methods read entire

contents ofguestbook.txtResponse.Write writes

text to client. Contains

XHTML markup rendered

on client browser.

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Fig. 33.12 Guestbook Active Server Page.

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Fig. 33.12 Guestbook Active Server Page.

Outline451 5/24/2001 tem: ASP is a great tool

for server-side development.

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Outline

XHTML generated by

guestbook.asp

(1 of 1)

for server side development.

2 5/24/2001 dan: ASP is my

preferred server-side development tool.

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Key name DescriptionAPPL_PHYSICAL_PATHReturns the physical path.HTTPS Boolean. Determines whether the request

came in through SSL (Secure Sockets Layer).

REMOTE_ADDR Clients DNS name or IP address.REQUEST_METHOD Request method (i.e., get and post).SERVER_NAME Servers hostname (DNS or IP address).HTTP_USER_AGENT

Returns information about the client makingthe request.

HTTP_COOKIE Returns cookies residing on the client.Fig. 33.13 Some server variable keys.

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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

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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

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Server-side include Commands embedded in XHTML documents

Add dynamic content

Places a .shtml include file within another file

Physical or virtual path

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 tag or delimiters

Outline501

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Outline3

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15 Instant Page Content Builder

16

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18 table { text-align:center;

19 font-size:12pt;

20 color:blue;

21 font-size:12pt;22 font-family:arial, sans-serif }

23

24

25

instantpage.asp

(1 of 4)

Outline5126

27 Server-side include

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Outliney28

29

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31 Instant Page Content Builder

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Outline51

52

53

54 Enter the Filename:

55

56

59

60

61

62 Enter the Title:

63

64

67

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69 70 Enter the content:

71

72

74 Replace this text with the

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Outline75 information you would like to post.

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instantpage.asp

(4 of 4)Server-side include

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Fig. 33.15 ASP that posts user information to process.asp.

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Outline571

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header.shtml

(1 of 1)

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Outline581

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footer.shtml

server-side include file

for the document footer

3

4 ordering information -

6 contact the editor

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Outline591

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28 Set fileObject = Server.CreateObject( _

29 "Scripting.FileSystemObject" )

30

31 directoryPath = _

32 Request.ServerVariables( "APPL_PHYSICAL_PATH" )

33

34 fileName = Request( "filename" ) & ".asp"

35

36 ' build path for text file

37 filePath = directoryPath & "\" & fileName

38

39 ' check if the file already exists

40 If fileObject.FileExists( filePath ) Then

41 message = "

" & "The file name is in use.
" & _

43 "Please use a different file name.
"
44 Session( "errorMessage" ) = message

45 Call Server.Transfer( "instantpage.asp" )

46 End If47

process.asp

(2 of 6)

name is entered and assigned

reference fileObject

Specify server path whereASP file is written

Request.ServerVariables

retrieves physical path Builds fileName by

concatenating

filename to the .asp

file extension

filePath passed FileExists

method. Determines if file exists.

If file exists, variable

errorMessage value is set to

XHTML containing error message

Server.Transfermethod

requests instantpage.asp

Outline6148 ' save XHTML for the welcome back message

49 ' in a session variable

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50 message = "

" & "Welcome Back, " & Request( "username" ) & _

52 "

"
53 Session( "welcomeBack" ) = message

54

55 Dim header, footer, textFile, openMark, closeMark

56 openMark = ""

58

59 ' build the header.

60 ' vbCrLf inserts a carriage return/linefeed into the text

61 ' string which makes the XHTML code more readable

62 header = openMark & " @LANGUAGE = VBScript " & closeMark _

63 & vbCrLf & openMark & " ' " & fileName _

64 & " " & closeMark & vbCrLf & vbCrLf _

65 & "" & vbCrLf & _69 "" & vbCrLf & "" & vbCrLf _

71 & "" & vbCrLf _

73 & "" & vbCrLf _

75 & "" & Request( "doctitle" ) & "" _

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process.asp

(4 of 6)

76 & vbCrLf & "" & vbCrLf & "" & vbCrLf _

77 & "" _

79 & vbCrLf & "" & Request( "doctitle" ) & "" & _

81 vbCrLf & "
" & vbCrLf

82

83 ' build the footer using a different style for

84 ' building the string

85 footer = vbCrLf & "

" & vbCrLf & _

86 "You have requested this page on " & _

87 openMark & " =Date() " & closeMark & "," & _

88 vbCrLf & "at " & openMark & " =Time() " & _

89 closeMark & "." & vbCrLf & _

90 "" _

92 & vbCrLf & vbCrLf & "" & vbCrLf & ""

93

Form values retrieved

using Request object

footer variable assigned

to XHTML footer contents

Outline6394 ' create the ASP file

95 Set textFile = fileObject.CreateTextFile( filePath, False )

96 i i

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process.asp

(5 of 6)

96 With textFile

97 Call .WriteLine( header & Request( "content" ) & _

98 footer )

99 Call .Close()

100 EndWith

101 %>

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103

105

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108

109

110 File Generated:

111

112

113 h2 { font-family:arial, sans-serif;

114 text-align:center }115

116

117

118

Lines 103-129 send XHTML to

client that contains link to

created page

Outline64119

120

121 h2 Fil % fil N %

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process.asp

(6 of 6)

121 File

122 was created successfully.

123

124

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126 View your file

127

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129

Outline65

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aboutme.asp

(1 of 2)

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10 About Me

11

12

13

14

15

16

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18 About Me

19

20 This page contains lots of exciting and interesting information about me!

21

22 You have requested this page on 10/15/2003,

23 at 11:45:47 AM.

24

25

Outline66

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27 ordering information

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aboutme.asp

(2 of 2)

28 href = "mailto:orders">ordering information -

29 contact the editor

31

32

33

34

67

33 7 S i T ki d C ki

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Fig. 33.20 Welcome back message displayed by instantpage.asp.

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33 7 Session Tracking and Cookies

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Fig. 33.21 Error message generated by instantpage.asp.

69

33 8 ActiveX Data Objects (ADO)

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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

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ADO

OLE DB

Legacy dataRelational data sources

Application or Browser

Non-relational data sources

ODBC

Fig. 33.22 Microsofts UDA architecture.

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Fig. 33.23 Portion of the ADO object model.

Field

Parameter

Fields

Error

Parameters

RecordSet

Errors

Command

Connection

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Object/Collection DescriptionConnection object Connects to the data source.Command object Contains the query that interacts with the database (the data

source) to manipulate data.

Parameter object Contains information needed by a Command object to querythe data source.

Parameterscollection Contains one or more Parameter objects.Error object Created when an error occurs while accessing data.Errors collection Contains one or more Error objects.Recordset object Contains zero or more records that match the database query.

Collectively, this group of records is called a recordset.

Field object Contains the value (and other attributes) of one data sourcefield.

Fields collection Contains one or more Field objects.Property

object Contains a characteristic of an ADO object.Propertiescollection Contains one or more Property objects.Record object Contains a single row of a Recordset.Stream object Contains a stream of binary data.Fig. 33.24 Some ADO object and collection types.

7333.9 Accessing a Database from an Active

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g

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


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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 Webpages

Restrict access

Password protection

Query Access database

Outline751

2

3

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g

28

29 errorString = Session( "errorString" )

30 errorString = errorString & "

Error (" _

32 & Err.Number & ") in " & Err.Source & "
" & _33 Err.Description & "

"
34 Session( "errorString" ) = errorString

35 End If

36 End Sub

37 %>

database.asp

(2 of 2)

Err object Number property

contains VBScript error

number. Tests if error has

occurred.

variable is assigned

XHTML text containing

error number and messageError number and message

concatenated to variableerrorString


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Server PageFig. 33.26 Error messages sent to login.asp by database.asp.

Outline781

2

3

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4 ' Fig. 33.27 : login.asp

5 ' ASP document to login to instantpage.asp

6 Option Explicit

7

8 ' create the SQL query

9 Session( "query" ) = "SELECT loginID FROM Users"

10 Call Server.Execute( "database.asp" )

11 %>

12

13

15

16

17

18

19 Login Page

20

21 22 table { text-align:center;

23 font-size:12pt;

24 color:blue;

25 font-size:12pt;

login.asp

(1 of 7)

Assigns SQL query

to session variable

queryExecutes database.asp to retrievelogin IDs from the database

Outline79

26font-family:arial, sans-serif }

27 .error { color:red }

28

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login.asp

(2 of 7)

29

30

31

32

33

34

35

40

Login attempt failed,

41 please try again

42

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login.asp

(3 of 7)

51

52

53 Name:

54

55 56

57

58 Select your name

59

60

67

68

69

70

select structure builds

drop-down list ofloginIDs

Requests loginID cookie

Selects the returning users

login ID option

Build loginID options

Outline81

71

72 Password:

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74 name = "password" />

75

76

77

78 79

80

81

82

83

84

85

86

87

92

93

94

login.asp

(4 of 7)

If false, print error

message to user

Outline82

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login.asp

(5 of 7)

98 Sub BuildReturning()

99 Dim found, loginData

100

101 Set loginData = Session( "loginData" )

102

103 ' pull user names from the record set to populate the

104 ' dropdown list

105 found = False

106

107 While Not loginData.EOF

108 ' create this record's dropdown entry

109 %>

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login.asp

(6 of 7)

123 Chr( 34 ) & "selected" & Chr( 34 ) )

124 found = True

125 End If

126 End If

127 %> value = "">128

129

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login.asp

(7 of 7)

136 Dim loginData

137


139

140 ' pull user names from the record set to populate the141 ' dropdown list

142 While Not loginData.EOF

143 ' create this record's dropdown entry

144 %>

145

146

while loop (lines 107-130) iterates

through loginDatas records Sets optionvalue to

current loginID

Writes optiondisplay as

current login ID

Increments the record set pointerto next record


S P

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Server PageFig. 33.27 ASP document that allows the user to log in to a site.


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Server PageFig. 33.27 ASP document that allows the user to log in to a site.

Outline87

1

2

3

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4 ' ASP document to check user's username and password

5 Option Explicit

6

7 ' test if a user name and a password were

8' entered. If not, transfer back to the login page.

9 If Request( "password" ) = ""Or _

10 Request( "loginID" ) = "noSelection"Then

11 Session( "loginFailure" ) = True

12 Call Server.Transfer( "login.asp" )

13 End If

14

15 Dim connection, loginData16

17 ' create the SQL query

18 Session( "query" ) = _

19 "SELECT * FROM Users WHERE loginID = '" & _

20 Request( "loginID" ) & "'"

21

22 Call Server.Execute( "database.asp" )


24

submitlogin.asp

(1 of 2)

field is empty or id

loginID field contains

default value

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.)

Checks password against the

password in recordset

If so, variable

loginFailureset to

true, client redirected

back to login.asp

Outline88

25

If Request( "password" ) = loginData( "password" ) Then26

27 ' password is OK, adjust loginFailure

If true line writes forms loginID

Sets session variableSets cookies expiration date to

current date plus 3 days

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28 Session( "loginFailure" ) = False

29

30 ' write a cookie to recognize them the next time they

31 ' go to login.asp

32 Response.Cookies( "loginID" ) = Request( "loginID" )33

34 ' give it three days to expire

35 Response.Cookies( "loginID" ).Expires = Date() + 3

36

37 ' send them to instantpage.asp

38 Call Server.Transfer( "instantpage.asp" )

39 Else

40 Session( "loginFailure" ) = True

41 Call Server.Transfer( "login.asp" )

42 End If

43 %>

submitlogin.asp

(2 of 2)

If true, line writes form s loginID

value as cookie named loginIDloginFailurevalue

to False

current date plus 3 days

Calls Server method Transfer to

redirect client to instantpage.asp

Otherwise loginFailure set to True

and client is redirected to login.asp


S P

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Server PageFig. 33.28 ASP document that validates user login.


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Server PageFig. 33.28 ASP document that validates user login.


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Server PageFig. 33.29 Cookies folder before and after cookie creation.

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p

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

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p

Component name DescriptionMSWC.BrowserType ActiveX component for gathering information about the

clients browser (e.g., type, version).MSWC.AdRotator ActiveX component for rotating advertisements on a

Web page.MSWC.NextLink ActiveX component for linking Web pages together.MSWC.ContentRotator ActiveX component for rotating HTML content on a

Web page.MSWC.PageCounter ActiveX component for storing the number of times a

Web page has been requested.MSWC.Counters ActiveX components that provide general-purpose

persistent counters.MSWC.MyInfo ActiveX component that provides information about a

Web site (e.g., owner name, owner address).Scripting.FileSystemObject

ActiveX component that provides an object library for

accessing files on the server or on the servers network.ActiveX Data Objects (ADO)Data Access Components ActiveX components that provide an object libraryfor accessing databases.Fig. 33.30 Some server-side ActiveX components.

Outline94

1

2

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4 ' Fig. 33.31 : component.asp

5 ' Demonstrating Server-side ActiveX Components

6 Option Explicit

7 %>

8

9

11

12

13

14

15 ActiveX Component Example

16

17

18

19

20

21Server-side ActiveX Components

22

23

24

component.asp

(1 of 4)

Outline95

25

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28 ' create an AdRotator object

29 Set rotator = Server.CreateObject( "MSWC.AdRotator" )

30

31 ' use config.txt to send an advertisement to the client

32 Call Response.Write( _33 rotator.GetAdvertisement( "config.txt" ) )

34

35 ' create a BrowserType object

36 Set browser = Server.CreateObject( "MSWC.BrowserType" )

37

38 If browser.VBScript = True Then

39 %>

40

41 Call Msgbox( "Client browser supports VBScript!" )

42

43

48

49 alert( "Client browser supports JavaScript!" );

50

component.asp

(2 of 4)

Creates AdRotator component instance,

assigns it reference rotator

GetAdvertisement called using referencerotator.

Retrieves advertisements from config.txt

Obtains information about users browser

Check property VBScript value

Test JavaScript property

Outline96

51

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54 get client s browser information

55 information = "

Your browser information is:
" & _

56 Request.ServerVariables( "HTTP_USER_AGENT" ) & _

57 "
Browser: " & browser.Browser & " Version: " & _

58 browser.Version & " Minor version: " & _59 browser.MinorVer & "
Cookies are "

60

61 If browser.Cookies Then

62 information = information & "enabled

"
63 Else

64 information = information & "disabled

"
65 End If

66

67 Call Response.Write( information )

68

69 ' create Page Counter Object

70 Set counter = Server.CreateObject( "MSWC.PageCounter" )

71 Call counter.PageHit() ' page has been "hit"

72 %>

component.asp

(3 of 4)

can obtain similar client information

Tests Cookies property to determine ifbrowser supports cookies

Increments number of hits by one

Passes server variable key

HTTP_USER_AGENT to

ServerVariables, obtains string

containing user information

Outline97

73

74

75

76 This page has been visited

Returns number of hits

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component.asp

(4 of 4)

76 This page has been visited

77 times!

78

79

98


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Fig. 33.31 Demonstrating server-side ActiveX components.


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Outline101

1 REDIRECT redirect.asp

2 width 54

3 height 36

4 border 1

Header contains

REDIRECT file URL

Advertisement dimensions

Image URL, destination URL,

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4 border 1

5 *

6 /images/us.gif

7 http://www.odci.gov/cia/publications/factbook/geos/us.html

8 United States Information9 20

10 /images/france.gif

11 http://www.odci.gov/cia/publications/factbook/geos/fr.html

12 France Information

13 20

14 /images/germany.gif

15 http://www.odci.gov/cia/publications/factbook/geos/gm.html

16 Germany Information

17 20

18 /images/italy.gif

19 http://www.odci.gov/cia/publications/factbook/geos/it.html

20 Italy Information

21 20

22 /images/spain.gif

23 http://www.odci.gov/cia/publications/factbook/geos/sp.html

24 Spain Information

25 20

config.txt

(1 of 1)

Asterisk separates header

from advertisementsalt value, image display ratio

Outline102

1

2

3

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redirect.asp

(1 of 1)

Fig. 33.33 : redirect.asp

5 ' Redirection Page for AdRotator Component

6 Option Explicit

7

8Call Response.Redirect( Request( "url" ) )

9 %>

4.2 ASP Basics

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