Add simple RBE node

function/rbe/rbe.js

@@ -0,0 +1,50 @@
+/**
+ * Copyright 2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+module.exports = function(RED) {
+    "use strict";
+
+    function RbeNode(n) {
+        RED.nodes.createNode(this,n);
+        this.func = n.func || "rbe";
+        this.gap = n.gap || 0;
+        var node = this;
+
+        var previous = null;
+        this.on("input",function(msg) {
+            if (this.func === "rbe") {
+                if (msg.payload != previous) {
+                    previous = msg.payload;
+                    node.send(msg);
+                }
+            }
+            else {
+                var n = parseFloat(msg.payload);
+                if (previous == null) { previous = n - node.gap; }
+                if (!isNaN(n)) {
+                    if (Math.abs(n - previous) >= node.gap) {
+                        previous = n;
+                        node.send(msg);
+                    }
+                }
+                else {
+                    node.warn("no number found in payload");
+                }
+            }
+        });
+    }
+    RED.nodes.registerType("rbe",RbeNode);
+}