Convert Attachment to CRM Document

A simple function for it doesn't exist I'm afraid.

You'll have to loop through all attachments, get the base64 encoded string, create a document using the NS classes and set the stream from the document.

You can create a function for it, though - something like this:

NSDocumentAgent docAgent;

Integer createCRMDocumentFromAttachment(Integer documentTypeId, Integer attachmentId, Integer contactId, Integer personId) {
    Integer documentId = -1;

    try {
        Attachment att;
        att.load(attachmentId);

        NSStream att_stream = decodeBase64AsStream(att.getBase64());

        NSDocumentEntity docEntity = docAgent.CreateDefaultDocumentEntity();
        
        // Set document attributes

        docEntity = docAgent.SaveDocumentEntity(docEntity);

        docAgent.SetDocumentStream(docEntity, att_stream, true);

        documentId = docEntity.GetDocumentId();
    }
    catch { 
        String errorMessage = "Exception caught: " + error + "...at " + errorLocation;
        // Do error handling
    }
    return documentId;
}