Add sample code to cancel all orders for a specified account

docs/samples/cancelall.js

@@ -0,0 +1,38 @@
+'use strict';
+const RippleAPI = require('../../dist/npm').RippleAPI; // require('ripple-lib')
+
+const address = 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K';
+const secret = '';
+
+const api = new RippleAPI({server: 'wss://s1.ripple.com:443'});
+const instructions = {maxLedgerVersionOffset: 5};
+
+function fail(message) {
+  console.error(message);
+  process.exit(1);
+}
+
+function cancelOrder(orderSequence) {
+  console.log('Cancelling order: ' + orderSequence.toString());
+  return api.prepareOrderCancellation(address, {orderSequence}, instructions)
+  .then(prepared => {
+    const signing = api.sign(prepared.txJSON, secret);
+    return api.submit(signing.signedTransaction);
+  });
+}
+
+function cancelAllOrders(orderSequences) {
+  if (orderSequences.length === 0) {
+    return Promise.resolve();
+  }
+  const orderSequence = orderSequences.pop();
+  return cancelOrder(orderSequence).then(() => cancelAllOrders(orderSequences));
+}
+
+api.connect().then(() => {
+  console.log('Connected...');
+  return api.getOrders(address).then(orders => {
+    const orderSequences = orders.map(order => order.properties.sequence);
+    return cancelAllOrders(orderSequences);
+  }).then(() => process.exit(0));
+}).catch(fail);