(VB.NET UWP/WinRT) Download Google Contact Photo

Demonstrates how to download Google Contact's photo.

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.

' --------------------------------------------------------------------------------------------------------
' Note: The code for setting up the Chilkat REST object and making the initial connection can be done once.
' Once connected, the REST object may be re-used for many REST API calls.
' (It's a good idea to put the connection setup code in a separate function/subroutine.)
' --------------------------------------------------------------------------------------------------------

' It is assumed we previously obtained an OAuth2 access token.
' This example loads the JSON access token file 
' saved by this example: Get Google Contacts OAuth2 Access Token

Dim jsonToken As New Chilkat.JsonObject
Dim success As Boolean = jsonToken.LoadFile("qa_data/tokens/googleContacts.json")
If (success <> True) Then
    Debug.WriteLine("Failed to load googleContacts.json")
    Exit Sub
End If


Dim gAuth As New Chilkat.AuthGoogle
gAuth.AccessToken = jsonToken.StringOf("access_token")

Dim rest As New Chilkat.Rest

' Connect using TLS.
Dim bAutoReconnect As Boolean = True
success = Await rest.ConnectAsync("www.google.com",443,True,bAutoReconnect)

' Provide the authentication credentials (i.e. the access token)
rest.SetAuthGoogle(gAuth)

' ----------------------------------------------
' OK, the REST connection setup is completed..
' ----------------------------------------------

' To get the photo, send the following:

' 	GET /m8/feeds/photos/media/default/contactId

rest.AddHeader("GData-Version","3.0")

Dim sbPath As New Chilkat.StringBuilder
' Get the photo for the contact having contactId = "1ea2e4fe0ef24e09"
Dim contactId As String = "1ea2e4fe0ef24e09"
sbPath.SetString("/m8/feeds/photos/media/default/{contactId}")
Dim numReplacements As Integer = sbPath.Replace("{contactId}",contactId)

Dim imageData As New Chilkat.BinData
success = Await rest.FullRequestNoBodyBdAsync("GET",sbPath.GetAsString(),imageData)
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


' A 404 response indicates the contact has no photo.
' (We could've first fetched the contact information, parsed out the 
' photo etag, and then if no photo etag existed, we'd know the contact has no
' photo.  Or... we can just try to download the photo and if a 404 is received,
' we know there's no photo.  Much simpler.)
If (rest.ResponseStatusCode = 404) Then
    Debug.WriteLine("This contact has no photo.")
    Exit Sub
End If


' A successful response will have a status code equal to 200.
If (rest.ResponseStatusCode <> 200) Then
    ' If the response was not successful, then the response body
    ' does not contain image data.  Instead it contains XML.
    Dim sbResponseBody As New Chilkat.StringBuilder
    sbResponseBody.AppendBd(imageData,"utf-8",0,0)

    Debug.WriteLine("response status code = " & rest.ResponseStatusCode)
    Debug.WriteLine("response status text = " & rest.ResponseStatusText)
    Debug.WriteLine("response header: " & rest.ResponseHeader)
    Debug.WriteLine("response body: " & sbResponseBody.GetAsString())
    Debug.WriteLine("request startline: " & rest.LastRequestStartLine)
    Debug.WriteLine("request header: " & rest.LastRequestHeader)
    Exit Sub
End If


' Examine the content-type in the response header so we know what file
' extension to use (.jpg, .png, etc.)
Dim sbContentType As New Chilkat.StringBuilder
sbContentType.Append(rest.ResponseHdrByName("Content-Type"))

If (sbContentType.ContentsEqual("image/jpeg",False) = True) Then
    imageData.WriteFile("qa_output/contact_photo.jpg")
End If

If (sbContentType.ContentsEqual("image/png",False) = True) Then
    imageData.WriteFile("qa_output/contact_photo.png")
End If


Debug.WriteLine("Content-Type: " & sbContentType.GetAsString())
Debug.WriteLine("Success.")