Published: Sunday, July 11, 1999
Grabbing Information from other Servers
Have you ever wanted to write an ASP page that did the following: execute an ASP script on another webserver;
retrieve that remote ASP script's output; and act on that output? Or perhaps you've always wanted to
be able to do remote Server Side Includes, like <!--#include file="http://www.someserver.com/somefile.txt"-->.
ASP, alone, can't do that sort of thing. There are, however, third party components that will!
There are two components that I am aware of. The first,
AspHttp, costs $49.95 for a single CPU liscense. Being a cheap skate, I am not going to discuss this
component, since I can't test it out without paying $50 bucks. Fortunately there is a free component,
AspTear, from Softwing. :)
This component is easy to install, and even easier to use. Let's say that you want to execute an ASP script
on another server that returns the current stock price for Microsoft. We could write our own ASP script
on our own server that would show this value, by simply doing:
'AspTear constants
Const Request_POST = 1
Const Request_GET = 2
Set objTear = CreateObject("SOFTWING.ASPtear")
Response.ContentType = "text/html"
On Error Resume Next
Dim strRetval
' URL, action, payload, username, password
strRetval = objTear.Retrieve("http://www.stockquotes.com/msft.asp", Request_GET, "", "", "")
If Err.Number <> 0 Then
Response.Write "<b>"
If Err.Number >= 400 Then
Response.Write "Server returned error: " & Err.Number
Else
Response.Write "Component/WinInet error: " & Err.Description
End If
Response.Write "</b>"
Response.End
End If
Response.Write "Microsoft currently selling at " & FormatCurrency(strRetval, 2)
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Please note that I have no idea if there even exists an http://stockquotes.com, I just made up an
example site/ASP script that might return Microsoft's current stock price.
It's pretty easy, eh? You can even send information in the QueryString or POST (to do so, you choose
Request_GET or Request_POST, respectively). So, let's say that there was an
ASP page that would return any stock quote. All you needed to do was specify the stock symbol in
the QueryString. Let's look at how the code for that might look:
'AspTear constants
Const Request_POST = 1
Const Request_GET = 2
Set objTear = CreateObject("SOFTWING.ASPtear")
Response.ContentType = "text/html"
On Error Resume Next
Dim strRetval
' URL, action, payload, username, password
strRetval = objTear.Retrieve("http://www.stockquotes.com/getquote.asp", Request_GET, "symbol=MSFT", "", "")
' ... Error checking code omitted ...
Response.Write "Microsoft currently selling at " & FormatCurrency(strRetval, 2)
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And you're not limited to executing just ASP scripts. You can grab raw HTML, or
execute Perl or CGI scripts. Pretty neat, eh?
Happy Programming!
