(VB.NET) Outlook -- Search Multiple Folders

I don't yet see how it's possible to do a recursive search of Outlook folders using the Microsoft Graph API. My best guess is to somehow use OData v4.0's $expand query option, but the hierarchical structure of the "mailFolder" and "messages" Microsoft Graph resources don't quite fit. Suggestions are welcome and can be sent to support@chilkatsoft.com.

This example will iterate over a list of folder previously obtained by a recursive traversal of the Outlook mail folders. (See the link in the example code below.)

A separate search is performed on each desired folder, and the results are combined into a single result set.

Note: This example requires Chilkat v9.5.0.68 or greater.

This example applies to: Exchange Online | Office 365 | Hotmail.com | Live.com | MSN.com | Outlook.com | Passport.com

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

Dim http As New Chilkat.Http

' Use your previously obtained access token here:
' See the following examples for getting an access token:
'    Get Microsoft Graph OAuth2 Access Token (Azure AD v2.0 Endpoint).
'    Get Microsoft Graph OAuth2 Access Token (Azure AD Endpoint).
'    Refresh Access Token (Azure AD v2.0 Endpoint).
'    Refresh Access Token (Azure AD Endpoint).

http.AuthToken = "MICROSOFT_GRAPH_ACCESS_TOKEN"


' This example will iterate over the folders previously discovered by recursively traversing the Outlook folders
' as shown in this example:  Outlook Recursive Folder Traversal)

' The XML map produced by the recursive traversal looks like this:

' 	<?xml version="1.0" encoding="utf-8"?>
' 	<hashtable>
' 	<e><k>/Sent Items</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEJAAAA</v></e>
' 	<e><k>/Inbox</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA</v></e>
' 	<e><k>/Junk Email</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEiAAAA</v></e>
' 	<e><k>/Inbox/xyz</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwEAAAA=</v></e>
' 	<e><k>/Inbox/abc/subFolderA/a</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwIAAAA=</v></e>
' 	<e><k>/Inbox/abc</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huv8AAAA=</v></e>
' 	<e><k>/Outbox</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgELAAAA</v></e>
' 	<e><k>/Inbox/abc/subFolderA</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwAAAQ==</v></e>
' 	<e><k>/Inbox/abc/subFolderB</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwMAAAA=</v></e>
' 	<e><k>/Archive</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAG8XunwAAAA=</v></e>
' 	<e><k>/Deleted Items</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEKAAAA</v></e>
' 	<e><k>/Drafts</k><v>AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEPAAAA</v></e>
' 	</hashtable>

' We'll iterate over the folders, and search all folders beginning with "/Inbox" (effectively, we're recursively searching
' everything under Inbox)
Dim xmlMap As New Chilkat.Xml
Dim success As Boolean = xmlMap.LoadXmlFile("qa_data/outlook/folderMap.xml")
If (success <> True) Then
    Debug.WriteLine("Failed to load XML folder map.")
    Exit Sub
End If



' We're going to return just the message id, subject, and FROM name/address.
http.SetUrlVar("select","id,subject,from")

' Our search will be for emails with the word "sample" in the subject.
http.SetUrlVar("filter","contains(subject,'sample')")

Dim json As New Chilkat.JsonObject
json.EmitCompact = False

Dim jsonCombined As New Chilkat.JsonObject
jsonCombined.EmitCompact = False

Dim sbResponse As New Chilkat.StringBuilder
Dim sbPath As New Chilkat.StringBuilder
Dim numFolders As Integer = xmlMap.NumChildren
Dim i As Integer = 0
Dim j As Integer = 0
Dim k As Integer = 0
While i < numFolders
    xmlMap.I = i
    sbPath.SetString(xmlMap.GetChildContent("e[i]|k"))

    If (sbPath.StartsWith("/Inbox",True) = True) Then

        Debug.WriteLine("------------------------------------------------------------------")
        Debug.WriteLine("Searching " & sbPath.GetAsString())

        ' Search this mail folder..
        http.SetUrlVar("folder_id",xmlMap.GetChildContent("e[i]|v"))

        sbResponse.Clear()
        success = http.QuickGetSb("https://graph.microsoft.com/v1.0/me/mailFolders/{$folder_id}/messages?$filter={$filter}&$select={$select}",sbResponse)
        If ((success <> True) And (http.LastStatus = 0)) Then
            Debug.WriteLine(http.LastErrorText)
            Exit Sub
        End If

        json.LoadSb(sbResponse)

        If (http.LastStatus <> 200) Then
            Debug.WriteLine("HTTP response status = " & http.LastStatus)
            Debug.WriteLine(json.Emit())
            Debug.WriteLine("Failed.")
            Exit Sub
        End If


        Debug.WriteLine(json.Emit())

        ' Each mail folder search will return JSON with a value array, which is non-empty if any matching messages were found:

        ' 			{
        ' 			  "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA')/messages(id,subject,from)",
        ' 			  "value": [
        ' 				Individual messages, if any, are listed here.
        ' 			  ]
        ' 			}

        Dim numMessages As Integer = json.SizeOfArray("value")
        j = 0
        While j < numMessages
            json.J = j

            ' Add this message to the final result set.
            jsonCombined.K = k
            jsonCombined.UpdateString("value[k].folderPath",sbPath.GetAsString())
            jsonCombined.UpdateString("value[k].id",json.StringOf("value[j].id"))
            jsonCombined.UpdateString("value[k].subject",json.StringOf("value[j].subject"))
            jsonCombined.UpdateString("value[k].from.emailAddress.name",json.StringOf("value[j].from.emailAddress.name"))
            jsonCombined.UpdateString("value[k].from.emailAddress.address",json.StringOf("value[j].from.emailAddress.address"))
            k = k + 1

            j = j + 1
        End While

    End If


    i = i + 1
End While


' Show the final combined JSON search result.
Debug.WriteLine("------------------------------------------------------------------")
Debug.WriteLine("Combined Search Results:")
Debug.WriteLine(jsonCombined.Emit())


' Sample output for the above program:

' ------------------------------------------------------------------
' Searching /Inbox
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA')/messages(id,subject,from)",
'   "value": [
'     {
'       "@odata.etag": "W/\"CQAAABYAAADn68XtMop0TpsYJGpfKXY9AADOpwfr\"",
'       "id": "AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgBGAAADsVyfxjDU406Ic4X7ill8xAcA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA5_vF7TKKdE6bGCRqXyl2PQAAAM6Jj10AAAA=",
'       "subject": "A sample email with Amazon in the body",
'       "from": {
'         "emailAddress": {
'           "name": "Chilkat Software",
'           "address": "support@chilkatsoft.com"
'         }
'       }
'     }
'   ]
' }
' 
' ------------------------------------------------------------------
' Searching /Inbox/xyz
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwEAAAA%3D')/messages(id,subject,from)",
'   "value": [
'   ]
' }
' 
' ------------------------------------------------------------------
' Searching /Inbox/abc/subFolderA/a
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwIAAAA%3D')/messages(id,subject,from)",
'   "value": [
'     {
'       "@odata.etag": "W/\"CQAAABYAAADn68XtMop0TpsYJGpfKXY9AADOpzfb\"",
'       "id": "AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgBGAAADsVyfxjDU406Ic4X7ill8xAcA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwIAAADn68XtMop0TpsYJGpfKXY9AAAAzombFQAAAA==",
'       "subject": "Sample email from admin@chilkat.io",
'       "from": {
'         "emailAddress": {
'           "name": "Chilkat Software",
'           "address": "admin@chilkat.io"
'         }
'       }
'     }
'   ]
' }
' 
' ------------------------------------------------------------------
' Searching /Inbox/abc
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huv8AAAA%3D')/messages(id,subject,from)",
'   "value": [
'   ]
' }
' 
' ------------------------------------------------------------------
' Searching /Inbox/abc/subFolderA
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwAAAQ%3D%3D')/messages(id,subject,from)",
'   "value": [
'   ]
' }
' 
' ------------------------------------------------------------------
' Searching /Inbox/abc/subFolderB
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders('AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwMAAAA%3D')/messages(id,subject,from)",
'   "value": [
'   ]
' }
' 
' ------------------------------------------------------------------
' Combined Search Results:
' {
'   "value": [
'     {
'       "folderPath": "/Inbox",
'       "id": "AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgBGAAADsVyfxjDU406Ic4X7ill8xAcA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA5_vF7TKKdE6bGCRqXyl2PQAAAM6Jj10AAAA=",
'       "subject": "A sample email with Amazon in the body",
'       "from": {
'         "emailAddress": {
'           "name": "Chilkat Software",
'           "address": "support@chilkatsoft.com"
'         }
'       }
'     },
'     {
'       "folderPath": "/Inbox/abc/subFolderA/a",
'       "id": "AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgBGAAADsVyfxjDU406Ic4X7ill8xAcA5_vF7TKKdE6bGCRqXyl2PQAAAL8huwIAAADn68XtMop0TpsYJGpfKXY9AAAAzombFQAAAA==",
'       "subject": "Sample email from admin@chilkat.io",
'       "from": {
'         "emailAddress": {
'           "name": "Chilkat Software",
'           "address": "admin@chilkat.io"
'         }
'       }
'     }
'   ]
' }
'