I have an MVC app that uploads an XLS file and imports it. Ther main issue is that these will often be password protected. Unfortunately we can't have Office on the server so interop is not an option server side. I was thinking that when the user browses to the file via their browser and clicks import that I could some how transform the file into plain old CSV before it actually gets to the server at which point I could do the main import. It's an intranet app so the clients will have Office.
So the question is, is there anypoint between the users selecting the file annd clicking upload where the file will be available for me to process on the browser side (where interop would be available) to transform the file?
Ended up using Syncfusion which does the job nicely.