The ERC721 standard is an interface for non-fungible tokens, also known as deeds. Let's see how HAL can be used to track events for one of the most adopted token, Crypto Kitties.
Track when a new auction for a kitten you like is created
1.
Create a new Event Trigger
2.
In the form field, insert 0x1f52b87C3503e537853e160adBF7E330eA0Be7C4 (SaleClockAuction)
3.
From the "contract event to watch" dropdown menu, select AuctionCreated
4.
In the "tokenId" field, insert the id for the kitten you want to track
You need to specify the right contract for the Event you're interested in watching. For example, AuctionCreated is defined in the SaleClockAuction contract (rather than in the main KittyCore contract).
Track when a kitten is ready to breed again
1.
Create a new Contract Trigger
2.
In the form field, insert 0x06012c8cf97bead5deae237070f9587f8e7a266d (KittyCore)
3.
From the "contract function to watch" dropdown menu, select isReadyToBreed
4.
In the _kittyId field, insert the id of the kitten you want to track
5.
In the "returns" field, select true.
Track when kitten ownership is assigned to you, including births
1.
Create a new Event Trigger
2.
In the form field, insert 0x06012c8cf97BEaD5deAe237070F9587f8E7A266d (KittyCore)
3.
From the "contract event to watch" dropdown menu, select Transfer
4.
In the "to" field, insert your address
The transfer event as defined in ERC721 is emitted every time a kitten ownership is assigned, including births. If you want to track specifically new births, you can use the Birth event instead.
Track when a certain kitten gives birth as a matron
1.
Create a new Event Trigger
2.
In the form field, insert 0x06012c8cf97BEaD5deAe237070F9587f8E7A266d
3.
From the "contract event to watch" dropdown menu, select Birth
4.
In the "matronId" field, insert the id for the kitten you want to track