Since Smart Contracts are event driven, can a new XML file thats generated by some remote system be an event source input to the smart contract?
I.e., when the XML file is generated on a folder e.g., /dir/ethereum, this smart contract is automatically evoked via web3j, javascript etc.
It's really not a question about smart contracts as they can't access anything outside the blockchain. You can do whatever you want outside the smart contract but when you want your contract to do something, you have to send it a transaction with whatever data you want it to process.
So feel free to add functionality outside the blockchain that creates a transaction for whatever event but remember that the contract needs to have all its data as an input in a transaction.
Have a look at for example Non Deterministic External Service Call for more information
