From bf343d0a3e52813fb6273d9abb4af91258d5684f Mon Sep 17 00:00:00 2001
From: Christian Weiske <cweiske@cweiske.de>
Date: Wed, 28 May 2014 17:21:17 +0200
Subject: [PATCH]

---
 rfidReader.js | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 130 insertions(+)
 create mode 100644 rfidReader.js

diff --git a/rfidReader.js b/rfidReader.js
new file mode 100644
index 0000000..509f2fb
--- /dev/null
+++ b/rfidReader.js
@@ -0,0 +1,130 @@
+rfidReader = {
+    webview: null,
+    connectionId: '',
+    connected: false,
+    infoInterval: null,
+    stringReceived: '',
+
+    /**
+     * Initialize the rfid reader connection and register the onReceive event
+     *
+     * @return void
+     */
+    init: function() {
+        var self = this;
+
+        window.addEventListener('load', function() {
+            self.webview = document.getElementById('guestportalWebview');
+
+            self.webview.addEventListener("loadstop", function() {
+                if (self.connected) {
+                    return;
+                }
+
+                // load all devices
+                chrome.serial.getDevices(self.getDevicesCallback);
+                chrome.serial.onReceive.addListener(self.onReceiveCallback);
+            });
+        });
+    },
+
+    /**
+     * Convert an array buffer into a string.
+     *
+     * @param array data
+     *
+     * @return String
+     */
+    convertArrayBufferToString: function (data) {
+        return String.fromCharCode.apply(null, new Uint8Array(data));
+    },
+
+    /**
+     * Removes not used numbers from the serial readout and trim it.
+     * This has to be done, otherwise the card id is not usable.
+     *
+     * Example:
+     * 39383431303030313131333036393032 converts to 9841000111306902
+     *
+     * @param String result
+     *
+     * @return String
+     */
+    convertResult: function(result) {
+        return result.replace(/\d(\d)/g, '$1').replace(/^\s+|\s+$/gm, '');
+    },
+
+    /**
+     * The callback for fetching the available serial devices.
+     *
+     * @param array ports Array of XXX with all available devices
+     *
+     * @return void
+     */
+    getDevicesCallback: function(ports) {
+        var path = null;
+
+        if (typeof ports === 'undefined') {
+            rfidReader.showError('No serial devices found.');
+            return;
+        } else if  (ports.length === 0) {
+            if (clientInformation.platform.match(/linux/i)) {
+                //we do not get any information about serial devices
+                // on linux, so we simply assume there is one
+                path = '/dev/ttyS0';
+            } else {
+                rfidReader.showError('No serial devices found.');
+                return;
+            }
+        } else {
+            path = ports[0].path;
+        }
+
+        // connect to the first serial device
+        chrome.serial.connect(path, {bitrate: 19200}, function(connectionInfo) {
+            if (typeof connectionInfo === 'undefined') {
+                rfidReader.showError('Cannot access serial device.');
+                return;
+            }
+            rfidReader.connectionId = connectionInfo.connectionId;
+            rfidReader.connected = true;
+        });
+    },
+
+    /**
+     * The callback for fetching the data sent by the serial reader.
+     *
+     * @param object info The readout from the serial port
+     *
+     * @return void
+     */
+    onReceiveCallback: function(info) {
+        if (info.connectionId == rfidReader.connectionId && info.data) {
+            var str = rfidReader.convertArrayBufferToString(info.data);
+
+            if (str.charAt(str.length-1) === "\n") {
+                rfidReader.stringReceived += str.substring(0, str.length-1);
+                rfidReader.stringReceived = rfidReader.convertResult(rfidReader.stringReceived);
+
+                if (rfidReader.stringReceived === '') {
+                    console.log('received an empty string');
+                    return;
+                }
+
+                // send the retreived data to the webview content
+                rfidReader.webview.contentWindow.postMessage({cardId: rfidReader.stringReceived}, '*');
+                rfidReader.stringReceived = '';
+            } else {
+                rfidReader.stringReceived += str;
+            }
+        }
+    },
+
+    showError: function(message) {
+        console.error(message);
+        document.getElementById('error').appendChild(document.createTextNode(message));
+        document.getElementById('error').style.display = 'block';
+    }
+};
+
+rfidReader.init();
-- 
2.30.2