gno.land/p/nt/grc721/v0⧉

1// PKGPATH: gno.land/r/demo/grc721veto23// Extension hooks run before the Transfer event is emitted, so a hook that vetoes4// a movement leaves nothing on the event stream. Only the second mint, which no5// hook refuses, is announced.6package grc721veto78import (9	"gno.land/p/nt/grc721/v0"10)1112type vetoExtension struct {13	refuse grc721.TokenID14}1516func (e *vetoExtension) ExtensionKind() string { return "veto" }1718func (e *vetoExtension) OnMint(to address, tid grc721.TokenID) {19	if tid == e.refuse {20		panic("veto: mint refused")21	}22}2324func (e *vetoExtension) OnTransfer(from, to address, tid grc721.TokenID) {}2526func (e *vetoExtension) OnBurn(tid grc721.TokenID) {}2728func main(cur realm) {29	_, ledger := grc721.NewToken("Veto", "VETO", 0, cur)30	ledger.RegisterExtension(&vetoExtension{refuse: "1"})3132	func() {33		defer func() { println("recovered:", recover()) }()34		ledger.Mint(cur.Address(), "1")35	}()3637	ledger.Mint(cur.Address(), "2")38}3940// Output:41// recovered: veto: mint refused4243// Events:44// [45//   {46//     "type": "NewToken",47//     "attrs": [48//       {49//         "key": "token",50//         "value": "gno.land/r/demo/grc721veto.VETO.0000000"51//       },52//       {53//         "key": "name",54//         "value": "Veto"55//       },56//       {57//         "key": "symbol",58//         "value": "VETO"59//       }60//     ],61//     "pkg_path": "gno.land/p/nt/grc721/v0"62//   },63//   {64//     "type": "Transfer",65//     "attrs": [66//       {67//         "key": "token",68//         "value": "gno.land/r/demo/grc721veto.VETO.0000000"69//       },70//       {71//         "key": "from",72//         "value": ""73//       },74//       {75//         "key": "to",76//         "value": "g1dywcn8v2jdpl6fuks8tw3l8gnzer0hv8mfkraa"77//       },78//       {79//         "key": "tokenId",80//         "value": "2"81//       }82//     ],83//     "pkg_path": "gno.land/p/nt/grc721/v0"84//   }85// ]86