The System Contract on V Systems is quite unique in that it is directly included in the protocol and not registered by users. Since Contract variables and VSYS tokens use different databases, it is normally not possible for them to interact. However, the System Contract handles the mixing of these two databases, and allows users to do things such as deposit and withdraw VSYS token from contracts.
// acnt: *vsys.Account
// ch: *vsys.Chain
// initial a new system contract on testnet
mainnetCtrt := vsys.NewSysCtrtForMainnet(acnt.Chain)
// initial a new system contract on testnet
testnetCtrt := vsys.NewSysCtrtForTestnet(acnt.Chain)
fmt.Println(mainnetCtrt.CtrtId)Example output
*vsys.CtrtId(vsys.Str(CCL1QGBqPAaFjYiA8NMGVhzkd3nJkGeKYBq))
Send VSYS tokens to another user.
// sc: *vsys.SysCtrt
// acnt0: *vsys.Account
// acnt1: *vsys.Account
// amount: float64
resp, err = sc.Send(
acnt0, // by
acnt1.Addr.B58Str().Str(), // receiver
10, // amount
"". // attachment
)
if err != nil {
log.Fatalln(err)
}
fmt.Println(resp)Example output
*vsys.BroadcastExecuteTxResp({TxBasic:{Type:vsys.TxType(9) Id:vsys.Str(GbkCZzjLjp57VpacQJiLrVkJfCAB6gTtkc2psY7o7t9i) Fee:vsys.VSYS(30000000) FeeScale:vsys.VSYS(100) Timestamp:vsys.VSYSTimestamp(1659931522952066000) Proofs:[{ProofType:vsys.Str(Curve25519) PubKey:vsys.Str(6VH5QC2ktUA5UK4j6c4hxQTZi4cm9jdNYhnCQV2rT4Wv) Addr:vsys.Str(AU8xJNjE5RNo8hmPYA1bSgQzPKYNgejytiP) Signature:vsys.Str(43BuiGTeX3WcHH5VxPe4RaNFSpjPHzwB8iSphuEzef4ASzFKwXagtoZy1ESeRXsnsQ9RanGsyH6Xro6C7KBDHgMC)}]} CtrtId:vsys.Str(CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt) FuncIdx:vsys.FuncIdx(0) FuncData:vsys.Str(14uNyN6a28tELN5meLbsyCHuaq8V5BX6rDJmU7ATMJaoF73Gfz7) Attachment:vsys.Str()})
Deposit VSYS tokens to a token-holding contract instance(e.g. lock contract).
Note that only the token defined in the token-holding contract instance can be deposited into it.
// sc: *vsys.SysCtrt
// acnt: *vsys.Account
// lc: *vsys.LockCtrt
// amount: float64
lcId := lc.CtrtId.B58Str().Str();
resp, err = sc.Deposit(
acnt, // by
lcId, // ctrtId
10, // amount
"", // attachment
)
if err != nil {
log.Fatalln(err)
}
fmt.Println(resp)Example output
*vsys.BroadcastExecuteTxResp({TxBasic:{Type:vsys.TxType(9) Id:vsys.Str(DhyyHBcUtUjv2oK9y1sqgCuca5WemN85eCcCsWkJy68J) Fee:vsys.VSYS(30000000) FeeScale:vsys.VSYS(100) Timestamp:vsys.VSYSTimestamp(1659931919720595000) Proofs:[{ProofType:vsys.Str(Curve25519) PubKey:vsys.Str(6VH5QC2ktUA5UK4j6c4hxQTZi4cm9jdNYhnCQV2rT4Wv) Addr:vsys.Str(AU8xJNjE5RNo8hmPYA1bSgQzPKYNgejytiP) Signature:vsys.Str(2hwfFsP5yhCriFpVm6YW7N1FKmmYGXe9ketHSSwYfdFh6NRaS4Q8E4TWFW55u2F5tuFRpj3dao8SGfnNwFp8WFn4)}]} CtrtId:vsys.Str(CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt) FuncIdx:vsys.FuncIdx(1) FuncData:vsys.Str(14VJY1ZthR99KumZMvcjjGnwmMggYiBsTzkczYTMmwdPNFkpULXaUg11ynCnJ7PAqewTixfGjTC6XwkJu1ucT1rf) Attachment:vsys.Str()})*vsys.BroadcastExecuteTxResp({TxBasic:{Type:vsys.TxType(9) Id:vsys.Str(DhyyHBcUtUjv2oK9y1sqgCuca5WemN85eCcCsWkJy68J) Fee:vsys.VSYS(30000000) FeeScale:vsys.VSYS(100) Timestamp:vsys.VSYSTimestamp(1659931919720595000) Proofs:[{ProofType:vsys.Str(Curve25519) PubKey:vsys.Str(6VH5QC2ktUA5UK4j6c4hxQTZi4cm9jdNYhnCQV2rT4Wv) Addr:vsys.Str(AU8xJNjE5RNo8hmPYA1bSgQzPKYNgejytiP) Signature:vsys.Str(2hwfFsP5yhCriFpVm6YW7N1FKmmYGXe9ketHSSwYfdFh6NRaS4Q8E4TWFW55u2F5tuFRpj3dao8SGfnNwFp8WFn4)}]} CtrtId:vsys.Str(CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt) FuncIdx:vsys.FuncIdx(1) FuncData:vsys.Str(14VJY1ZthR99KumZMvcjjGnwmMggYiBsTzkczYTMmwdPNFkpULXaUg11ynCnJ7PAqewTixfGjTC6XwkJu1ucT1rf) Attachment:vsys.Str()})
Withdraw VSYS tokens from a token-holding contract instance(e.g. lock contract).
Note that only the one who deposits the token can withdraw.
// acnt0: *vsys.Account
// sc: *vsys.SysCtrt
// lc: *vsys.LockCtrt
// amount: float64
const lcId = lc.ctrtId.data;
lcId := lc.CtrtId.B58Str().Str();
resp, err = sc.Withdraw(
acnt, // by
lcId, // ctrtId
10, // amount
"", // attachment
)
if err != nil {
log.Fatalln(err)
}
fmt.Println(resp)Example output
*vsys.BroadcastExecuteTxResp({TxBasic:{Type:vsys.TxType(9) Id:vsys.Str(77DECrd5HAJu5fNNisM3fSG6xK6i5CUHBnDSLkEsrchR) Fee:vsys.VSYS(30000000) FeeScale:vsys.VSYS(100) Timestamp:vsys.VSYSTimestamp(1659931920016001000) Proofs:[{ProofType:vsys.Str(Curve25519) PubKey:vsys.Str(6VH5QC2ktUA5UK4j6c4hxQTZi4cm9jdNYhnCQV2rT4Wv) Addr:vsys.Str(AU8xJNjE5RNo8hmPYA1bSgQzPKYNgejytiP) Signature:vsys.Str(38pBkU2PnXCDLP3rVzAMtARYBqBCK3dho57URFwWrdibvCEgBfSfnjA15gcfhDTEeeUFZFgsoV7JSn5CKXzyLc7e)}]} CtrtId:vsys.Str(CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt) FuncIdx:vsys.FuncIdx(2) FuncData:vsys.Str(14WMYfjwYyNiNDuXJCfYqBWCzreXBLEjt4a8mrixiYxU8qT6ofpWGMuMqQGRmireKtWF2yz9aTqpA8UwUJxWFGfh) Attachment:vsys.Str()})
Transfer the VSYS token to another account(e.g. user or contract).
transfer is the underlying action of send, deposit, and withdraw. It is not recommended to use transfer directly. Use send, deposit, withdraw instead when possible.
// acnt0: *vsys.Account
// acnt1: *vsys.Account
// nc: *vsys.SysCtrt
// amount: float64
resp, err = sc.Transfer(
acnt0, // by
acnt0.Addr.B58Str().Str(),
acnt1.Addr.B58Str().Str(), // ctrtId
10, // amount
"", // attachment
)
if err != nil {
log.Fatalln(err)
}
fmt.Println(resp)Example output
*vsys.BroadcastExecuteTxResp({TxBasic:{Type:vsys.TxType(9) Id:vsys.Str(CMPfS49owQmWAt2hRwKWK7dC9JRdxfMoiQGex4UuMmhi) Fee:vsys.VSYS(30000000) FeeScale:vsys.VSYS(100) Timestamp:vsys.VSYSTimestamp(1659932081561444000) Proofs:[{ProofType:vsys.Str(Curve25519) PubKey:vsys.Str(6VH5QC2ktUA5UK4j6c4hxQTZi4cm9jdNYhnCQV2rT4Wv) Addr:vsys.Str(AU8xJNjE5RNo8hmPYA1bSgQzPKYNgejytiP) Signature:vsys.Str(5jdWvUsehLxoUGA1PK61ZBWaMjUJygg9bxohRG1gXM85cww4WFFfRwUqWiZ8j37cLhf3XLqBkr3ffz7xL3SAqM3F)}]} CtrtId:vsys.Str(CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt) FuncIdx:vsys.FuncIdx(3) FuncData:vsys.Str(14VJY1ZthR99KumZMvcjjGnwmMggYiBsTzkczYTL1fh62FGgJmJfWBJ1yGDjL7nEHzYr6iGDzhVwK4KCQnkkLAij) Attachment:vsys.Str()})