Does Transfer event fire for transactions in pending status (not confirmed) on ethereum platform?

Question

I am developing a software that deals with smart-contract in ethereum platform (ERC20) that transfers tokens from one wallet to another. I have ethereum node (geth) deployed on my server that listens for events.

I need to catch Transfer events whenever someone sends tokens to my smart-contract. Is it possible? I just in doubt when I would receive transfer event:

1. When transaction was already approved? or
2. When transaction was just created and then when it was confirmed/rejected?

I need to achieve the second behavior. Is it possible?

Answer 1

You will receive the event when the transaction is included in a block. I guess you call it "approved"

Keep in mind that some blocks that you initially see in the main chain may end up in a forkchain, thus your Transfer will be "reverted". This is quite an unlikely event but it's good if your system can handle it.