Chilkat Examples

ChilkatHOMEAndroid™Classic ASPCC++C#Mono C#.NET Core C#C# UWP/WinRTDataFlexDelphi ActiveXDelphi DLLVisual FoxProJavaLianjaMFCObjective-CPerlPHP ActiveXPHP ExtensionPowerBuilderPowerShellPureBasicCkPythonChilkat2-PythonRubySQL ServerSwift 2Swift 3,4,5...TclUnicode CUnicode C++Visual Basic 6.0VB.NETVB.NET UWP/WinRTVBScriptXojo PluginNode.jsExcelGo

VB.NET UWP/WinRT Examples

Web API Categories

ASN.1
Amazon EC2
Amazon Glacier
Amazon S3
Amazon S3 (new)
Amazon SES
Amazon SNS
Amazon SQS
Azure Cloud Storage
Azure Service Bus
Azure Table Service
Base64
Bounced Email
Box
CAdES
CSR
CSV
Certificates
Compression
DKIM / DomainKey
DSA
Diffie-Hellman
Digital Signatures
Dropbox
Dynamics CRM
EBICS
ECC
Ed25519
Email Object
Encryption
FTP
FileAccess
Firebase
GMail REST API
GMail SMTP/IMAP/POP
Geolocation
Google APIs
Google Calendar
Google Cloud SQL
Google Cloud Storage
Google Drive
Google Photos
Google Sheets
Google Tasks
Gzip
HTML-to-XML/Text
HTTP

HTTP Misc
IMAP
JSON
JSON Web Encryption (JWE)
JSON Web Signatures (JWS)
JSON Web Token (JWT)
Java KeyStore (JKS)
MHT / HTML Email
MIME
MS Storage Providers
Microsoft Graph
NTLM
OAuth1
OAuth2
OIDC
Office365
OneDrive
OpenSSL
Outlook
Outlook Calendar
Outlook Contact
PDF Signatures
PEM
PFX/P12
PKCS11
POP3
PRNG
REST
REST Misc
RSA
SCP
SCard
SFTP
SMTP
SSH
SSH Key
SSH Tunnel
ScMinidriver
SharePoint
Socket/SSL/TLS
Spider
Stream
Tar Archive
Upload
WebSocket
XAdES
XML
XML Digital Signatures
XMP
Zip
curl

 

 

 

(VB.NET UWP/WinRT) REST Follow Redirects

Demonstrates how to follow a 302/303 redirect response.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads

Chilkat for the Universal Windows Platform (UWP)

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim rest As New Chilkat.Rest

Dim bTls As Boolean = True
Dim port As Integer = 443
Dim bAutoReconnect As Boolean = True
Dim success As Boolean = Await rest.ConnectAsync("chilkatsoft.com",port,bTls,bAutoReconnect)
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


' Send a POST to a URL that will respond with a 302 redirect..
rest.AddQueryParam("firstName","John")
rest.AddQueryParam("lastName","Doe")
Dim responseText As String = Await rest.FullRequestFormUrlEncodedAsync("POST","/echoPost302.asp")
If (rest.LastMethodSuccess <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


Dim statusCode As Integer = rest.ResponseStatusCode

' Examine the response status code
If (statusCode < 300) Then
    Debug.WriteLine("Not a redirect.")
    Debug.WriteLine(responseText)
    Exit Sub
End If


If (statusCode > 399) Then
    Debug.WriteLine("Error response: Status code = " & statusCode)
    Debug.WriteLine(responseText)
    Exit Sub
End If


Debug.WriteLine("Redirect status code = " & statusCode)

' 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.

Debug.WriteLine(rest.ResponseHeader)

Dim redirectUrl As Chilkat.Url = rest.RedirectUrl()
If (rest.LastMethodSuccess = False) Then
    Debug.WriteLine("No Location header found for redirect.")
    Exit Sub
End If


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

' Disconnect and re-connect.  
' (This can be skipped if both the host and SSL/TLS conditions are the same.)
Await rest.DisconnectAsync(100)
success = Await rest.ConnectAsync(redirectUrl.Host,redirectUrl.Port,redirectUrl.Ssl,bAutoReconnect)
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


If ((statusCode = 301) Or (statusCode = 307)) Then
    ' Redirect using a POST, sending the same params to the new destination
    rest.AddQueryParam("firstName","John")
    rest.AddQueryParam("lastName","Doe")
    responseText = Await rest.FullRequestFormUrlEncodedAsync("POST",redirectUrl.Path)
    If (rest.LastMethodSuccess <> True) Then
        Debug.WriteLine(rest.LastErrorText)
        Exit Sub
    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 = Await rest.FullRequestFormUrlEncodedAsync("GET",redirectUrl.PathWithQueryParams)
    If (rest.LastMethodSuccess <> True) Then
        Debug.WriteLine(rest.LastErrorText)
        Exit Sub
    End If

End If


' Show the final status code and the response text.
Debug.WriteLine("Final status code = " & rest.ResponseStatusCode)

Debug.WriteLine("Final response text (HTML, XML, JSON, or whatever..)")
Debug.WriteLine(responseText)

 

© 2000-2022 Chilkat Software, Inc. All Rights Reserved.