Simplified API for creating transactions

I propose to add a simplified API for creating a single operation transactions. New methods will be added to Server class and names representing operations that will be created:

var StellarSdk = require('stellar-sdk');
var server = new StellarSdk.Server('https://horizon-testnet.stellar.org');
server.payment({
    source: 'SCZZ5GHGUAY4OVME5G5FRQEF5XWBWMAIISB3GXPU24F3VHLMU75NAM4S',
    destination: 'GC3FALN2RUQIYG2T4I5JIMSFQO6ZAVSRBC22E5TS3Q7Y7MUDIHM5X5M6',
    amount: '10',
    asset: StellarSdk.Asset.native()
  }).then(result => {
    console.log(result);
  });

is equivalent of the following code built using current API:

var StellarSdk = require('stellar-sdk');

var keypair = StellarSdk.Keypair.fromSeed('SCZZ5GHGUAY4OVME5G5FRQEF5XWBWMAIISB3GXPU24F3VHLMU75NAM4S');
var server = new StellarSdk.Server('https://horizon-testnet.stellar.org');

server.loadAccount(keypair.accountId())
  .then(function(source) {
    var transaction = new StellarSdk.TransactionBuilder(source)
      .addOperation(StellarSdk.Operation.payment({
        destination: 'GD6WU64OEP5C4LRBH6NK3MHYIA2ADN6K6II6EXPNVUR3ERBXT4AN4ACD',
        amount: "10",
        asset: StellarSdk.Asset.native()
      }))
      .build();

    transaction.sign(keypair);

    server.submitTransaction(transaction)
      .then(function(result) {
        console.log(result);
      });
  });

[bartekn]

If anyone’s interested in something similar: Stellar Burrito.

[morleyzhi]

@bartekn I’m wary of adding API calls that do the same thing as existing calls, as we have to explain how they’re different (if at all), and that message might not come across. I think other packages like StellarBurrito (or alternate SDKs that we make) fill that need a lot better than the main SDK, which I think should focus on feature-completeness and backwards compatibility. So I’ll close this issue for now.

@Pedity-Luffy new Server().loadAccount doesn’t return an AccountCallBuilder instance:

https://stellar.github.io/js-stellar-sdk/Server.html#loadAccount

You’re right that it’s a little confusing that some Server functions return CallBuilders and some don’t. I split that off into a separate issue:

https://github.com/stellar/js-stellar-sdk/issues/228

…but since that will be a breaking change that requires deprecating some endpoints, it might get deprioritized in favor of fixes that don’t break backwards compatibility.