ASP Web Form To Check Existence of A Remote URL

Category:

ASP, HTML and XML

Type:

Snippets

Difficulty:

Beginning

Author:

Anonymous

Version Compatibility: ASP, Visual Basic Script

More information:

There are 2 parts in the example; a basic HTML page to capture a URL that be checked, and the asp code that checks whether the URL does or does not exist. I use this routine because we have multiple webs capturing data that is then saved in a central administrative web. I need to make sure that the admin Web page is available before I send data to it for processing.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
None

Code:

HTML Page with a form to type in the URL. The function to call the asp page is just a way I prefer to code.

</script>
<form>
  <p>Enter the URL including the http declaration<br>
  <br>
  <input type="text" name="CheckURL" size="60"><br>
  <br>
  <input type="button" value="Check URL" name="CheckAddress" onclick="postForm(this.form, 'xxx.asp')">
  </p>
</form>
</body>
</html>

ASP Page to check the URL -  to make this example work, you must saved it as CheckURL.asp and in the same directory as the HTML page.

<% 
//
// Get the URL to be checked from the html form
//
	CheckURL = request.form("CheckURL")
// 
// create an XMLHTTP object that is the vehicle for the page check
//
	Set GetConnection = CreateObject("Microsoft.XMLHTTP")
// 
// open a path to the chosen URL and attempt to send data to it
//
	GetConnection.Open "get", CheckURL, False 
	GetConnection.Send()
// 
// check the return code, 200 mean OK, all the rest are warnings or errors
// If 200 is returned, this script redirects to the valid page, if not it returns an error statement
//
	if GetConnection.status = 200 then
		response.redirect (CheckURL)
	else
		response.write ("<br>Error code " & GetConnection.status & " detected<br><br>Status codes are at the end of page<br><br><a href='http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/html/f6de15fc-72e9-418e-b275-d94b0b2045de.asp'>http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/html/f6de15fc-72e9-418e-b275-d94b0b2045de.asp</a>")
	end if
//
// get rid of the XMLHTTP object 
//
	Set GetConnection = Nothing
%>