CODEWITHSUNDEEP
office365office365api
nigelgomm
nigelgomm

Reputation: 89

download an attachment from office365 rest api knowing only the attachmentItemID

Drag and dropping a file from a browser logged into office365/outlook gives me a JSON string with the attachmentItemId but not the message ID. 

attachmentV{"itemType":"attachment","attachmentFile":{"attachmentItemId":"AAMkADhmNz......","name":"feb invoices archive.pdf","size":64276,"fileType":5,"type":"ItemIdAttachment:#Exchange"}}

Yet the only endpoints I can see for fetching an attachment require the messageID.

e.g. GET https://outlook.office.com/api/v2.0/me/messages/{message_id}/attachments/{attachment_id}

Is there a way to download an attachment without knowing the message id?

Upvotes: 0

Views: 378

Answers (2)

Frederick Grumieaux
Frederick Grumieaux

Reputation: 478

I found a way to get the messageId based on the attachmentItemId.

It seems that if you make this call:

HTTP GET GET https://graph.microsoft.com/v1.0/me/messages/{attachmentItemId}

You get the same response as if you would have made this call:

HTTP GET GET https://graph.microsoft.com/v1.0/me/messages/{messageId}

And that response is a JSON object that has an id property, which will be the message id.

So once you have that, you can just do this call:

HTTP GET https://graph.microsoft.com/v1.0/me/messages/{message_id}/attachments/{attachment_id}

You would expect that if you use that last call with twice the attachment-id parameter it should also work, but no. I have no idea where this would be documented, or how they expect you to figure this out... But I guess it is a bit better then searching for all attachments by name

PS: I assume that my solution that calls the graph api with a user token will work the same way as the outlook.office.com api that was used in the question. But I have not tested it.

Upvotes: 0

nigelgomm
nigelgomm

Reputation: 89

best i could find so far is to search messages for the file name

.../messages/?$search="attachment:{Name}"&$expand=Attachments

and then loop through the returned messages and their attachments looking for the specific id.

not ideal... but it's working.

n.b. you have to replace any "/" characters with "-" and any "+" with "_" in the attachmentid when comparing with the id returned in the search.

Upvotes: 0

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