Upload file to Microsoft Graph/Sharepoint API

graph_upload.R

# I struggled with uploading things to Microsoft Graph API/Sharepoint/OneDrive for business
# here's the code that finally worked for me.

library(AzureGraph)
library(httr)

# Creates authentication token via browser 
graph_token <- AzureGraph::create_graph_login()$token

# Send a PUT request to the Microsoft Graph API

AzureGraph::call_graph_url(graph_token,
               "https://graph.microsoft.com/v1.0/sites/{site-id}/drives/{drive-id}/root:/filename.txt:/content",
               body = httr::upload_file('path/filename.txt'),
               encode = 'multipart',
               http_verb = "PUT")
               
# I found Graph Explorer helpful for finding the correct site-id and drive-id 
# (I was uploading to a Sharepoint subsite's document library and it took a while to find). 
# httr:upload_file() encodes the file in a suitable way for uploading to Graph - and 
# you need to pass encode = 'multipart' for it to work correctly.