(VB.NET) Page Through All Contacts

Demonstrates how to page through the entire list of Google Contacts.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

' 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 = rest.Connect("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..
' ----------------------------------------------

Dim startIndex As Integer = 1
Dim maxResults As Integer = 25
' The totalResults will get updated with the correct value in the 1st loop iteration..
Dim totalResults As Integer = 100
' To retrieve the contacts in pages of 25 each, we need to send the following for each page.

' 	GET /m8/feeds/contacts/default/full?max-results=25&start-index=<startIndex>
' 	GData-Version: 3.0

Dim sbMaxResults As New Chilkat.StringBuilder
sbMaxResults.AppendInt(maxResults)
Dim sbStartIndex As New Chilkat.StringBuilder

Dim loopIteration As Integer = 0
While startIndex <= totalResults

    sbStartIndex.Clear()
    sbStartIndex.AppendInt(startIndex)

    rest.ClearAllHeaders()
    rest.ClearAllQueryParams()
    rest.AddHeader("GData-Version","3.0")
    rest.AddQueryParam("start-index",sbStartIndex.GetAsString())
    rest.AddQueryParam("max-results",sbMaxResults.GetAsString())

    Dim sbResponseBody As New Chilkat.StringBuilder
    success = rest.FullRequestNoBodySb("GET","/m8/feeds/contacts/default/full",sbResponseBody)
    If (success <> True) Then
        Debug.WriteLine(rest.LastErrorText)
        Exit Sub
    End If


    ' A successful response will have a status code equal to 200.
    If (rest.ResponseStatusCode <> 200) Then
        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())
        Exit Sub
    End If


    ' If the 200 response was received, then the contacts XML is contained
    ' in the response body.
    Dim xml As New Chilkat.Xml
    xml.LoadSb(sbResponseBody,False)

    ' Now let's parse the XML...

    ' Get the the total number of results, the start index, and the items per page.
    ' We'll likely NOT get the full list, but will instead get the 1st page.
    totalResults = xml.GetChildIntValue("openSearch:totalResults")
    Dim startIndex2 As Integer = xml.GetChildIntValue("openSearch:startIndex")
    Dim itemsPerPage As Integer = xml.GetChildIntValue("openSearch:itemsPerPage")
    Debug.WriteLine("totalResults = " & totalResults)
    Debug.WriteLine("startIndex = " & startIndex2)
    Debug.WriteLine("itemsPerPage = " & itemsPerPage)

    ' Iterate over each contact.
    Dim numEntries As Integer = xml.NumChildrenHavingTag("entry")
    Dim i As Integer = 0
    While i < numEntries
        xml.I = i
        Debug.WriteLine((loopIteration * maxResults + i + 1) & " ----")
        Debug.WriteLine("title: " & xml.GetChildContent("entry[i]|title"))

        Dim idUrl As String = xml.GetChildContent("entry[i]|id")
        Debug.WriteLine("id: " & idUrl)

        Dim fullName As String = xml.ChilkatPath("entry[i]|gd:name|gd:fullName|*")
        If (xml.LastMethodSuccess = True) Then
            Debug.WriteLine("fullName: " & fullName)
        End If


        Dim emailAddress As String = xml.ChilkatPath("entry[i]|gd:email|(address)")
        If (xml.LastMethodSuccess = True) Then
            Debug.WriteLine("email address: " & emailAddress)
        End If


        ' Find the photo link and check to see if this contact has a photo.
        Dim xLink As Chilkat.Xml = xml.GetChildWithAttr("link","rel","http://schemas.google.com/contacts/2008/rel#photo")
        If (xml.LastMethodSuccess = True) Then
            ' Get the photo etag.
            Dim bHasPhoto As Boolean = xLink.HasAttribute("gd:etag")
            If (bHasPhoto = True) Then
                Debug.WriteLine("This contact has a photo.")
            End If


        End If


        i = i + 1
    End While

    startIndex = startIndex + maxResults
    loopIteration = loopIteration + 1
End While