Re-added code to clean branch

content/_code-samples/build-a-wallet/desktop-js/2_async-poll.js

@@ -0,0 +1,75 @@
+const async = require('async')
+const { app, BrowserWindow } = require('electron')
+const path = require('path')
+const xrpl = require("xrpl")
+
+const TESTNET_URL = "wss://s.altnet.rippletest.net:51233"
+
+/**
+ * This function sends a ledger-request and returns the response
+ *
+ * @param client
+ * @returns {Promise<*>}
+ */
+const getValidatedLedgerData = async (client) => {
+    // Reference: https://xrpl.org/ledger.html#ledger
+    const ledgerRequest = {
+        "command": "ledger",
+        "ledger_index": "validated"
+    }
+    const ledgerResponse = await client.request(ledgerRequest)
+
+    return ledgerResponse.result
+}
+
+/**
+ * This function creates our application window
+ *
+ * @returns {Electron.CrossProcessExports.BrowserWindow}
+ */
+const createWindow = () => {
+
+    const appWindow = new BrowserWindow({
+        width: 1024,
+        height: 768,
+        webPreferences: {
+            preload: path.join(__dirname, 'view', '2_preload.js'),
+        },
+    })
+
+    appWindow.loadFile(path.join(__dirname, 'view', '2_async.html'))
+
+    return appWindow
+}
+
+/**
+ * This function creates a XRPL client, continuously polls the XRPL with a ledger-request and broadcasts
+ * the result by dispatching the 'update-ledger-data' event which will be picked up by the frontend
+ *
+ * @returns {Promise<void>}
+ */
+const main = async () => {
+    const appWindow = createWindow()
+
+    const client = new xrpl.Client(TESTNET_URL)
+
+    await client.connect()
+
+    async.forever(
+        function(next) {
+            getValidatedLedgerData(client).then((value) => {
+                appWindow.webContents.send('update-ledger-data', value)
+            })
+
+            setTimeout(function() {
+                next()
+            }, 2500)
+        },
+        function(err) {
+            // if next is called with a value in its first parameter, it will appear
+            // in here as 'err', and execution will stop.
+        }
+    )
+}
+
+app.whenReady().then(main)