(Classic ASP) REST Follow Redirects

Demonstrates how to follow a 302/303 redirect response.

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

<html>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<%
' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Rest")
set rest = Server.CreateObject("Chilkat.Rest")

bTls = 1
port = 443
bAutoReconnect = 1
success = rest.Connect("chilkatsoft.com",port,bTls,bAutoReconnect)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
    Response.End
End If

' Send a POST to a URL that will respond with a 302 redirect..
success = rest.AddQueryParam("firstName","John")
success = rest.AddQueryParam("lastName","Doe")
responseText = rest.FullRequestFormUrlEncoded("POST","/echoPost302.asp")
If (rest.LastMethodSuccess <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
    Response.End
End If

statusCode = rest.ResponseStatusCode

' Examine the response status code
If (statusCode < 300) Then
    Response.Write "<pre>" & Server.HTMLEncode( "Not a redirect.") & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( responseText) & "</pre>"
    Response.End
End If

If (statusCode > 399) Then
    Response.Write "<pre>" & Server.HTMLEncode( "Error response: Status code = " & statusCode) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( responseText) & "</pre>"
    Response.End
End If

Response.Write "<pre>" & Server.HTMLEncode( "Redirect status code = " & statusCode) & "</pre>"

' The response header will contain a Location field with the redirect URL, such as this:
' Location: http://www.chilkatsoft.com/echoPostFinal.asp

' The response status code determines how the client should behave.
' Here are some common possibilities:

' 301: Moved Permanently
' This and all future requests should be directed to the given URI.  (Keep the original HTTP method for the redirect.  In this case, the 
' original request was a POST, so we POST to the redirect URL.)

' 302: Found (aka Object Moved aka Moved Temporarily)
' This is the most popular redirect code, but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945 ) required the client
' to perform a temporary redirect (the original describing phrase was �Moved Temporarily�), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1
' added status codes 303 and 307 to disambiguate between the two behaviors. However, the majority of Web applications and frameworks still use the 302 status code
' as if it were the 303.

' 303: See Other
' The response to the request can be found under another URI using a GET method. When received in response to a PUT, it should be assumed that the server has
' received the data and the redirect should be issued with a separate GET message.

' 307: Temporary Redirect
' In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method
' should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.

Response.Write "<pre>" & Server.HTMLEncode( rest.ResponseHeader) & "</pre>"

' redirectUrl is a Chilkat.Url
Set redirectUrl = rest.RedirectUrl()
If (rest.LastMethodSuccess = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( "No Location header found for redirect.") & "</pre>"
    Response.End
End If

' Prep for the redirect..
success = rest.ClearAllParts()

' Disconnect and re-connect.  
' (This can be skipped if both the host and SSL/TLS conditions are the same.)
success = rest.Disconnect(100)
success = rest.Connect(redirectUrl.Host,redirectUrl.Port,redirectUrl.Ssl,bAutoReconnect)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
    Response.End
End If

If ((statusCode = 301) Or (statusCode = 307)) Then
    ' Redirect using a POST, sending the same params to the new destination
    success = rest.AddQueryParam("firstName","John")
    success = rest.AddQueryParam("lastName","Doe")
    responseText = rest.FullRequestFormUrlEncoded("POST",redirectUrl.Path)
    If (rest.LastMethodSuccess <> 1) Then
        Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
        Response.End
    End If

End If

If ((statusCode = 302) Or (statusCode = 303)) Then
    ' Redirect using a GET, sending the query params found in the redirect URL.
    responseText = rest.FullRequestFormUrlEncoded("GET",redirectUrl.PathWithQueryParams)
    If (rest.LastMethodSuccess <> 1) Then
        Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
        Response.End
    End If

End If

' Show the final status code and the response text.
Response.Write "<pre>" & Server.HTMLEncode( "Final status code = " & rest.ResponseStatusCode) & "</pre>"

Response.Write "<pre>" & Server.HTMLEncode( "Final response text (HTML, XML, JSON, or whatever..)") & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( responseText) & "</pre>"

%>
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