VB.NET

Upload a File to a SharePoint Documents Library using HttpCurl

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This example shows how to use Chilkat's HttpCurl class to upload a local file to the root of a SharePoint Documents document library. The example uses Microsoft Graph to automatically resolve the SharePoint site name to a site ID, find the drive ID for the Documents library, and then upload helloChilkat.txt so it is stored in SharePoint as example.txt. A successful upload returns 201 Created when a new file is created, or 200 OK when an existing file is updated or replaced.

VB.NET

Dim success As Boolean = False

' This example uploads a local file to the root of a SharePoint
' Documents document library.
' 
' The local file:
' 
'   qa_data/helloChilkat.txt
' 
' is uploaded and stored in SharePoint as:
' 
'   example.txt
' 
' The example demonstrates how HttpCurl automatically resolves:
' 
'   site_name  -> site_id
'   site_id    -> document_library_id
' 
' and then uploads the file to the target document library using
' the Microsoft Graph file upload API.

success = False

' --------------------------------------------------------------------------------------------------------
' Before running this example, create an Azure App Registration and grant it
' the Microsoft Graph permissions required to access SharePoint.
' 
' The application will authenticate using OAuth2 Client Credentials.
' See:
' How to Create SharePoint App Registration for OAuth 2.0 Client Credentials
' --------------------------------------------------------------------------------------------------------

' Build a JSON authentication configuration.
' HttpCurl will use this information to automatically obtain OAuth2 access tokens.
Dim jsonAuth As New Chilkat.JsonObject

' Enable secret lookup.
' 
' Instead of hard-coding sensitive values such as the client ID,
' client secret, and token endpoint, secret specification strings
' are used.  Chilkat automatically retrieves the actual values from
' Windows Credential Manager (Windows) or Apple Keychain (macOS).
' 
' See:
' Secret Specification Strings
jsonAuth.EnableSecrets = True

success = jsonAuth.UpdateString("oauth2.client_id","!!sharepoint|oauth2|client_id")
If (success = True) Then
    success = jsonAuth.UpdateString("oauth2.client_secret","!!sharepoint|oauth2|client_secret")
End If

If (success = True) Then
    success = jsonAuth.UpdateString("oauth2.token_endpoint","!!sharepoint|oauth2|token_endpoint")
End If

If (success = False) Then
    Debug.WriteLine(jsonAuth.LastErrorText)
    Exit Sub
End If


' Request Microsoft Graph permissions that were granted to the application.
jsonAuth.UpdateString("oauth2.scope","https://graph.microsoft.com/.default")

' ---------------------------------------------------------------------------------------------------

Dim curl As New Chilkat.HttpCurl

' Associate the OAuth2 configuration with HttpCurl.
' 
' When the request is executed, Chilkat automatically obtains an access token
' if needed and adds the Authorization: Bearer header to the HTTP request.
curl.SetAuth(jsonAuth)

' Define values that are already known.
' 
' These variables are referenced in curl commands using
' {{variable_name}} substitution syntax.
curl.SetVar("sharepoint_hostname","example.sharepoint.com")
curl.SetVar("site_name","test")

' The upload request requires a Microsoft Graph site ID.
' 
' Because the application only knows the SharePoint site name,
' define a helper function that can retrieve the site information.
curl.AddFunction("getSite","GET https://graph.microsoft.com/v1.0/sites/root:/sites/{{site_name}}")

' Extract the site's ID and store it in the HttpCurl variable named site_id.
curl.AddOutput("getSite","id","site_id")

' The upload request also requires the drive ID of the Documents
' document library.
' 
' Microsoft Graph refers to document libraries as "drives".
curl.AddFunction("getDrives","GET https://graph.microsoft.com/v1.0/sites/{{site_id}}/drives")

' Search the returned drives for the one named "Documents"
' and save its drive ID in the document_library_id variable.
curl.AddOutput2("getDrives","value","name","Documents",True,"id","document_library_id")

' This is the target Microsoft Graph request.
' 
' PUT /drives/{drive-id}/root:/{filename}:/content
' 
' This endpoint uploads a file to a document library.  If the target
' file already exists, Microsoft Graph replaces the existing content.
' If the file does not exist, a new file is created.
' 
' The --data-binary option uploads the contents of the local file
' exactly as stored on disk.
' 
' The uploaded file will be named "example.txt" in the root of the
' Documents document library.
Dim curlCommand As String = "curl -X PUT -H ""Content-Type: text/plain; charset=utf-8"" --data-binary @qa_data/helloChilkat.txt ""https://graph.microsoft.com/v1.0/drives/{{document_library_id}}/root:/example.txt:/content"""

' Execute the request.
' 
' HttpCurl examines the target request and determines that
' document_library_id is required.
' 
' To obtain this value, it automatically builds and executes
' the following dependency chain:
' 
'   1) getSite    -> site_id
'   2) getDrives  -> document_library_id
'   3) upload     -> example.txt
' 
' The final response returned by DoYourThing is the response
' from the upload request.
success = curl.DoYourThing(curlCommand)
If (success = False) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


' A successful upload can return:
' 
'   201 (Created)
'       A new file was created.
' 
'   200 (OK)
'       An existing file was updated or replaced.
' 
' Any other status code typically indicates an authentication,
' permission, site lookup, document library lookup, or upload error.
Dim statusCode As Integer = curl.StatusCode
If ((statusCode <> 201) And (statusCode <> 200)) Then
    Debug.WriteLine(curl.ResponseBodyStr)
    Debug.WriteLine("status code = " & statusCode)
    Exit Sub
End If


' The file has been uploaded successfully and is now available
' in the root of the Documents document library as:
' 
'   example.txt
' 
Debug.WriteLine("Success.")