Create signedTransaciton locally

[soichisumi]

Is there any method to create signedTransaction locally?

I want to create signed transaction without connection with ripple server.
like:

api.preparePayment(address, payment)
    .then(prepared => {
        const signRes = api.sign(prepared.txJSON, secret);
    }).catch(fail);

I already succeeded to create and send a signed transaction like the following snippet:

api.connect().then(()=>{
     console.log('connected...');
     return api.preparePayment(address, payment, instructions).then(prepared => {
         console.log('Payment transaction prepared....');
        
         const signRes = api.sign(prepared.txJSON, secret);
         console.log('Payment transaction signed....');
         const txHash = signRes.id;
         console.log(`txhash: ${txHash}`);
         api.submit(signRes.signedTransaction).then(quit, fail);
     });
 }).catch(fail);

[intelliot]

Yes. The sign() method works without a connection to a ripple server. You need to provide all of the transaction instructions like the sequence number, fee, etc.

[soichisumi]

I understood preparePayment() need to connect internet to correct information of ripple network.
So if I correct information(like fee, etc) beforehand, no need to connect internet in signing.

I succeed to sign transaction like this snippet:

const txJSON = '{"Flags":2147483648,"TransactionType":"AccountSet","Account":"r9cZA1mLK5R5Am25ArfXFmqgNwjZgnfk59","Domain":"726970706C652E636F6D","LastLedgerSequence":8820051,"Fee":"12","Sequence":23}';
var r = api.sign(txJSON, secret);

Thank you for your advice, @intelliot !

[intelliot]

@yoyoyousei Cool - that works. Note that writing txJSON that way requires using the rippled API's transaction format. The preparePayment() and most other prepare* methods can be used offline if you specify the fee, sequence, and maxLedgerVersion parameters. See this page: Offline functionality.

[soichisumi]

@intelliot wow. So if I fee, sequence and maxLedgerVersion specified in instructions, txJson is generated in offline.
I'll try it. Thank you for additional information!

[soichisumi]

As you said, I succeeded to get txJson in offline, by specifying fee, sequence and maxLedgerVersion in instructions. Thank you!