submit batch transaction

[bhaagiKenpachi]

I want to submit a batch tx which consists of 2 txs. One tx is system::remark and balances::transfer. Is there any function to submit batch tx?

[cdamian]

Hi @bhaagiKenpachi,

Please see the below example:

func main() {
	api, err := gsrpc.NewSubstrateAPI("ws://localhost:9946")
	if err != nil {
		panic(err)
	}

	meta, err := api.RPC.State.GetMetadataLatest()
	if err != nil {
		panic(err)
	}

	rv, err := api.RPC.State.GetRuntimeVersionLatest()
	if err != nil {
		panic(err)
	}

	genesisHash, err := api.RPC.Chain.GetBlockHash(0)
	if err != nil {
		panic(err)
	}

	aliceStorageKey, err := types.CreateStorageKey(meta, "System", "Account", signature.TestKeyringPairAlice.PublicKey)
	if err != nil {
		panic(err)
	}

	var accountInfo types.AccountInfo

	ok, err := api.RPC.State.GetStorageLatest(aliceStorageKey, &accountInfo)
	if err != nil || !ok {
		panic(err)
	}

	call1, err := types.NewCall(meta, "System.remark", []byte{})
	if err != nil {
		panic(err)
	}

	call2, err := types.NewCall(meta, "System.remark", []byte{})
	if err != nil {
		panic(err)
	}

	batchCall, err := types.NewCall(meta, "Utility.batch_all", []types.Call{call1, call2})
	if err != nil {
		panic(err)
	}

	ext := types.NewExtrinsic(batchCall)

	signOpts := types.SignatureOptions{
		BlockHash:          genesisHash, // using genesis since we're using immortal era
		Era:                types.ExtrinsicEra{IsMortalEra: false},
		GenesisHash:        genesisHash,
		Nonce:              types.NewUCompactFromUInt(uint64(accountInfo.Nonce)),
		SpecVersion:        rv.SpecVersion,
		Tip:                types.NewUCompactFromUInt(0),
		TransactionVersion: rv.TransactionVersion,
	}

	if err := ext.Sign(signature.TestKeyringPairAlice, signOpts); err != nil {
		panic(err)
	}

	sub, err := api.RPC.Author.SubmitAndWatchExtrinsic(ext)

	if err != nil {
		panic(err)
	}

	defer sub.Unsubscribe()

	select {
	case <-time.After(1 * time.Minute):
		panic("Timeout reached")
	case st := <-sub.Chan():
		extStatus, _ := st.MarshalJSON()
		fmt.Println("Done with status -", string(out))
	case err := <-sub.Err():
		panic(err)
	}
}

[bhaagiKenpachi]

@cdamian Thanks for your quick response. Will try and let you know.

[bhaagiKenpachi]

@cdamian In the code you got hash of block 0. Should I also do the same for any scenario or should I get latest block?

[cdamian]

@bhaagiKenpachi for the genesis hash you always need the first block.

[bhaagiKenpachi]

@cdamian So it should always be genesis hash at blockhash or I should include latest block hash near blockhash?

signOpts := types.SignatureOptions{
		BlockHash:          genesisHash, // using genesis since we're using immortal era
		Era:                types.ExtrinsicEra{IsMortalEra: false},
		GenesisHash:        genesisHash,
		Nonce:              types.NewUCompactFromUInt(uint64(accountInfo.Nonce)),
		SpecVersion:        rv.SpecVersion,
		Tip:                types.NewUCompactFromUInt(0),
		TransactionVersion: rv.TransactionVersion,
	}

is genesis hash field is compulsory in signature options?

[cdamian]

@bhaagiKenpachi for signature options, yes.

[bhaagiKenpachi]

@cdamian So it should always be genesis hash at blockhash or I should include latest block hash near blockhash?
What about above question?

signOpts := types.SignatureOptions{
		BlockHash:          genesisHash, // using genesis since we're using immortal era
		Era:                types.ExtrinsicEra{IsMortalEra: false},
		GenesisHash:        genesisHash,
		Nonce:              types.NewUCompactFromUInt(uint64(accountInfo.Nonce)),
		SpecVersion:        rv.SpecVersion,
		Tip:                types.NewUCompactFromUInt(0),
		TransactionVersion: rv.TransactionVersion,
	}

is genesis hash field is compulsory in signature options? ( YES)

[bhaagiKenpachi]

@cdamian So it should always be genesis hash at blockhash or I should include latest block hash near blockhash?
What about above question?

[cdamian]

@bhaagiKenpachi genesis hash is mandatory in the signature opts.

So it should always be genesis hash at blockhash or I should include latest block hash near blockhash?

If you are using immortal eras, that one should be the genesis hash. If you were using mortal eras then a different block hash would have to be used.

[bhaagiKenpachi]

@cdamian I want to go with mortal tx for now. Can you suggest the what can be the changes?

[cdamian]

@bhaagiKenpachi mortal eras are a WIP for us at this point - #286. We have yet to test the changes in this PR and eventually merge it. You are more than welcome to try it out and also contribute to it.

[bhaagiKenpachi]

@cdamian why did you use storage here?

[cdamian]

@cdamian why did you use storage here?

To retrieve the account info that is required in the signature opts.

[bhaagiKenpachi]

@cdamian I have sent friend request on discord. Can you please accept?. For faster communication.

[mikiquantum]

@bhaagiKenpachi lets try to keep this conversation as public as possible in case that other people run into the same questions later on.
For further support, please use the public channel on discord. Thanks!