(VB.NET) Google Contacts - Retrieve as JSON

Demonstrates how to retrieve Google Contacts as JSON.

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' 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..
' ----------------------------------------------

' To retrieve the contacts, we need to send the following:

' 	GET /m8/feeds/contacts/default/full
' 	GData-Version: 3.0


' To get the contacts data in JSON format, set the "alt" query parameter to "json"
rest.AddQueryParam("alt","json")
rest.AddHeader("GData-Version","3.0")

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 JSON is contained
' in the response body.
Dim json As New Chilkat.JsonObject
json.LoadSb(sbResponseBody)
json.EmitCompact = False

' Save the pretty-printed JSON response to a file.
sbResponseBody.Clear()
json.EmitSb(sbResponseBody)
sbResponseBody.WriteFile("qa_output/google_contacts.json","utf-8",False)

' Parse the Google Contacts JSON, and iterate over the contacts..
Dim totalResults As Integer = json.IntOf("feed.openSearch$totalResults.$t")
Dim startIndex As Integer = json.IntOf("feed.openSearch$startIndex.$t")
Dim itemsPerPage As Integer = json.IntOf("feed.openSearch$itemsPerPage.$t")
Debug.WriteLine("totalResults = " & totalResults)
Debug.WriteLine("startIndex = " & startIndex)
Debug.WriteLine("itemsPerPage = " & itemsPerPage)

Dim numEntries As Integer = json.SizeOfArray("feed.entry")
Dim i As Integer = 0
While i < numEntries
    json.I = i
    Debug.WriteLine((i + 1) & " ----")
    Debug.WriteLine("title: " & json.StringOf("feed.entry[i].title.$t"))

    Dim fullName As String = json.StringOf("feed.entry[i].gd$name.gd$fullName.$t")
    If (json.LastMethodSuccess = True) Then
        Debug.WriteLine("fullName: " & fullName)
    End If


    ' There can be multiple email addresses, so it's stored as a JSON array..
    Dim numEmailAddresses As Integer = json.SizeOfArray("feed.entry[i].gd$email")
    Dim j As Integer = 0
    While j < numEmailAddresses
        Dim emailAddress As String = json.StringOf("feed.entry[i].gd$email[j].address")
        If (json.LastMethodSuccess = True) Then
            Debug.WriteLine("email address: " & emailAddress)
        End If

        j = j + 1
    End While

    i = i + 1
End While

' A sample Google Contacts JSON response:

' 	{ 
' 	  "version": "1.0",
' 	  "encoding": "UTF-8",
' 	  "feed": { 
' 	    "xmlns": "http://www.w3.org/2005/Atom",
' 	    "xmlns$openSearch": "http://a9.com/-/spec/opensearch/1.1/",
' 	    "xmlns$gContact": "http://schemas.google.com/contact/2008",
' 	    "xmlns$batch": "http://schemas.google.com/gdata/batch",
' 	    "xmlns$gd": "http://schemas.google.com/g/2005",
' 	    "gd$etag": "\"QHw5eTVSLyt7I2A9XRFaE0kNTwI.\"",
' 	    "id": { 
' 	      "$t": "chilkat.support@gmail.com"
' 	    },
' 	    "updated": { 
' 	      "$t": "2016-11-17T01:57:41.221Z"
' 	    },
' 	    "category": [
' 	      { 
' 	        "scheme": "http://schemas.google.com/g/2005#kind",
' 	        "term": "http://schemas.google.com/contact/2008#contact"
' 	      }
' 	    ],
' 	    "title": { 
' 	      "$t": "Chilkat Support's Contacts"
' 	    },
' 	    "link": [
' 	      { 
' 	        "rel": "alternate",
' 	        "type": "text/html",
' 	        "href": "https://www.googleapis.com/"
' 	      },
' 	      { 
' 	        "rel": "http://schemas.google.com/g/2005#feed",
' 	        "type": "application/atom+xml",
' 	        "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full"
' 	      },
' 	      { 
' 	        "rel": "http://schemas.google.com/g/2005#post",
' 	        "type": "application/atom+xml",
' 	        "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full"
' 	      },
' 	      { 
' 	        "rel": "http://schemas.google.com/g/2005#batch",
' 	        "type": "application/atom+xml",
' 	        "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full/batch"
' 	      },
' 	      { 
' 	        "rel": "self",
' 	        "type": "application/atom+xml",
' 	        "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full?max-results=25&alt=json"
' 	      },
' 	      { 
' 	        "rel": "next",
' 	        "type": "application/atom+xml",
' 	        "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full?max-results=25&alt=json&start-index=26"
' 	      }
' 	    ],
' 	    "author": [
' 	      { 
' 	        "name": { 
' 	          "$t": "Chilkat Support"
' 	        },
' 	        "email": { 
' 	          "$t": "chilkat.support@gmail.com"
' 	        }
' 	      }
' 	    ],
' 	    "generator": { 
' 	      "version": "1.0",
' 	      "uri": "http://www.google.com/m8/feeds",
' 	      "$t": "Contacts"
' 	    },
' 	    "openSearch$totalResults": { 
' 	      "$t": "350"
' 	    },
' 	    "openSearch$startIndex": { 
' 	      "$t": "1"
' 	    },
' 	    "openSearch$itemsPerPage": { 
' 	      "$t": "25"
' 	    },
' 	    "entry": [
' 	      { 
' 	        "id": { 
' 	          "$t": "http://www.google.com/m8/feeds/contacts/chilkat.support%40gmail.com/base/0"
' 	        },
' 	        "gd$etag": "\"SX8zcTVSLyt7I2A9WxBXFU4MQwI.\"",
' 	        "updated": { 
' 	          "$t": "2010-01-26T20:07:48.189Z"
' 	        },
' 	        "app$edited": { 
' 	          "xmlns$app": "http://www.w3.org/2007/app",
' 	          "$t": "2010-01-26T20:07:48.189Z"
' 	        },
' 	        "category": [
' 	          { 
' 	            "scheme": "http://schemas.google.com/g/2005#kind",
' 	            "term": "http://schemas.google.com/contact/2008#contact"
' 	          }
' 	        ],
' 	        "title": { 
' 	          "$t": "Joe Sample"
' 	        },
' 	        "link": [
' 	          { 
' 	            "rel": "http://schemas.google.com/contacts/2008/rel#photo",
' 	            "type": "image/*",
' 	            "href": "https://www.googleapis.com/m8/feeds/photos/media/chilkat.support%40gmail.com/0"
' 	          },
' 	          { 
' 	            "rel": "self",
' 	            "type": "application/atom+xml",
' 	            "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full/0"
' 	          },
' 	          { 
' 	            "rel": "edit",
' 	            "type": "application/atom+xml",
' 	            "href": "https://www.googleapis.com/m8/feeds/contacts/chilkat.support%40gmail.com/full/0"
' 	          }
' 	        ],
' 	        "gd$name": { 
' 	          "gd$fullName": { 
' 	            "$t": "Joe Sample"
' 	          },
' 	          "gd$givenName": { 
' 	            "$t": "Joe"
' 	          },
' 	          "gd$familyName": { 
' 	            "$t": "Sample"
' 	          }
' 	        },
' 	        "gd$email": [
' 	          { 
' 	            "address": "somebody@gmail.com",
' 	            "primary": "true",
' 	            "rel": "http://schemas.google.com/g/2005#other"
' 	          }
' 	        ]
' 	      },
' 		... more entries ...
'