"request" Object - Receiving Data from Client

ASP Tutorials - Herong's Tutorial Examples

∟"request" Object - Receiving Data from Client

This section provides a tutorial example on how to use the 'request' object provided by the ASP programming interface to receive data from the client, the Web browser.

The request object is a very rich object. It contains everything the client sends to the server:

QueryString: A read only collection object representing all the names and values sent from the browser by the GET method.
Form: A read only collection object representing all names and values sent from the browser by the POST method.
Cookies: A read only collection object representing all the cookies sent from the browser.
ServerVariables: A read only collection object representing all the names and values in the HTTP request header and in the server environment.
TotalBytes: A read only property indicating the total number of bytes in this request.
BinaryRead(): A method to read all names and values sent from the browser by the POST method.

The following ASP page shows how to access the property and collections of the request object.

<script language="vbscript" runat="server">
'  request_test.asp
'  Copyright (c) 2002 by Dr. Herong Yang
'  This program shows how to use the "request" object.
'
   response.write("<html><body>")
   response.write("<b>Tests on the request object</b>:<br/>")
   response.write("Total bytes = " & request.TotalBytes & "<br/>")
   set c = request.QueryString
   response.write("QueryString.Count = " & c.Count & "<br/>")
   for each v in c
      response.write( v & " = " & c.Item(v) & "<br/>")
   next
   set c = request.Form
   response.write("Form.Count = " & c.Count & "<br/>")
   for each v in c
      response.write( v & " = " & c.Item(v) & "<br/>")
   next
   set c = request.ServerVariables
   response.write("ServerVariables.Count = " & c.Count & "<br/>")
   for each v in c
      response.write( v & " = " & c(v) & "<br/>")
   next
   set c = request.Cookies
   response.write("Cookies.Count = " & c.Count & "<br/>")
   for each v in c
      response.write( v & " = " & c(v) & "<br/>")
   next
   set c = request.ClientCertificate
   response.write("ClientCertificate.Count = " & c.Count & "<br/>")
   for each v in c
      response.write( v & " = " & c(v) & "<br/>")
   next
   response.write("</body></html>")
</script>

Output:

Tests on the request object:
Total bytes = 0
QueryString.Count = 0
Form.Count = 0
ServerVariables.Count = 49
ALL_HTTP = HTTP_ACCEPT:*/* HTTP_ACCEPT_LANGUAGE:en-us HTTP_CONNECTION:...
ALL_RAW = Accept: */* Accept-Language: en-us Connection: Keep-Alive ...
APPL_MD_PATH = /LM/W3SVC/1/ROOT
APPL_PHYSICAL_PATH = c:\inetpub\wwwroot\
AUTH_PASSWORD = 
AUTH_TYPE = 
AUTH_USER = 
CERT_COOKIE = 
CERT_FLAGS = 
CERT_ISSUER = 
CERT_KEYSIZE = 
CERT_SECRETKEYSIZE = 
CERT_SERIALNUMBER = 
CERT_SERVER_ISSUER = 
CERT_SERVER_SUBJECT = 
CERT_SUBJECT = 
CONTENT_LENGTH = 0
CONTENT_TYPE = 
GATEWAY_INTERFACE = CGI/1.1
HTTPS = off
HTTPS_KEYSIZE = 
HTTPS_SECRETKEYSIZE = 
HTTPS_SERVER_ISSUER = 
HTTPS_SERVER_SUBJECT = 
INSTANCE_ID = 1
INSTANCE_META_PATH = /LM/W3SVC/1
LOCAL_ADDR = 127.0.0.1
LOGON_USER = 
PATH_INFO = /request_test.asp
PATH_TRANSLATED = c:\inetpub\wwwroot\request_test.asp
QUERY_STRING = 
REMOTE_ADDR = 127.0.0.1
REMOTE_HOST = 127.0.0.1
REMOTE_USER = 
REQUEST_METHOD = GET
SCRIPT_NAME = /request_test.asp
SERVER_NAME = localhost
SERVER_PORT = 80
SERVER_PORT_SECURE = 0
SERVER_PROTOCOL = HTTP/1.1
SERVER_SOFTWARE = Microsoft-IIS/5.0
URL = /request_test.asp
HTTP_ACCEPT = */*
HTTP_ACCEPT_LANGUAGE = en-us
HTTP_CONNECTION = Keep-Alive
HTTP_HOST = localhost
HTTP_USER_AGENT = Mozilla/4.0 (compatible; MSIE 6.0; MSNIA; Windows NT...
HTTP_COOKIE = ASPSESSIONIDQQGQQVFQ=DFPLLCDACFFBCIBMCKALNNMK
HTTP_ACCEPT_ENCODING = gzip, deflate
Cookies.Count = 0
ClientCertificate.Count = 0

A couple of interesting things to note here:

The collection object can be iterated by the "for each k in c" statement, where "k" is the key of each in the collection.
Since "c.Item(k)" is the default method, it can be written as "c(k)".
The ServerVariables object contains a lot of information, including remote host IP address, URL, translated path name, etc.

If you request this ASP page with the following url:

http://localhost/request_test.asp?Name=Bill+Smith&Country=Canada

You will see the following changes in the output:

Tests on the request object:
QueryString.Count = 2
Name = Bill Smith
Country = Canada
ServerVariables.Count = 49
...
QUERY_STRING = Name=Bill+Smith&Country=Canada

What happens here is:

When you request a Web page with a URL contains a "?", everything after "?" in the URL will be received by the server as the query string.
The query string will be store in the server variable called "QUERY_STRING". It will also be split into pairs of names and values and stored in "QueryString" collection.
"&" is used in the query string as delimiters.
Special characters in the query string need to be encoded. For example, " " is encoded as "+". I believe ASP offers both URL encoding and decoding methods.