Setting Data with the Go SDK

Question

I recently started using the Go SDK to interact with the horizon testnet.

I am able to read data from the account key/value store using the func (*Account) GetData method:

stellarAcc, err := client.LoadAccount(accountId)
if err != nil {
   log.Println("Stellar AccountId not found")
   return
}
res, _ := stellarAcc.GetData(key)
s := string(res[:5])
log.Printf("Value: %s", s)

I can't find in the documentation any method to set a new key/value pair. Is it possible with the current state of the SDK?

Answer 1

I now understand that you have to build the transaction yourself using build. Example if anyone else gets stuck:

import (
    build "github.com/stellar/go/build"
    "github.com/stellar/go/clients/horizon"
)

var b = []byte("Hello, goodbye, etc!")

tx, err := build.Transaction(
    build.SourceAccount{AddressOrSeed: accountId},
    build.TestNetwork,
    build.AutoSequence{SequenceProvider: horizon.DefaultTestNetClient},
    build.SetData("key", b),
)
if err != nil {
     panic(err)
}
txe, err := tx.Sign("xxx")
if err != nil {
    panic(err)
}

txeB64, err := txe.Base64()

if err != nil {
    panic(err)
}

fmt.Printf("tx base64: %s", txeB64)

resp, err := horizon.DefaultTestNetClient.SubmitTransaction(txeB64)
if err != nil {
    panic(err)
}

fmt.Println("transaction posted in ledger:", resp.Ledger)

Answer 2

You need to build the transaction and include the SetData operation.

Sample code:

import "github.com/stellar/go/build"

tx, err := build.Transaction(
    build.SourceAccount{AddressOrSeed: accountId},
    build.TestNetwork,
    build.AutoSequence{SequenceProvider: horizon.DefaultTestNetClient},
    build.SetData("key", []byte("value")),  // data value is a []byte
)

Note that when you read the data from horizon it will be in base64 format and will need to be decoded to give the original "value" string.