Let rbe node compare to previous input OR output

closes #192 and #193
Also update info and test.

function/rbe/README.md

@@ -38,6 +38,11 @@ output only if greater than + or - the *band gap* away from the previous output.
 It can also be set to block values more than a certain distance away from the present value.
 This can be used to remove outliers or unexpected readings.
 
+You can specify compare with *previous valid output value* or *previous input value*.
+The former ignores any values outside the valid range, whereas the latter allows
+two "bad" readings in a row to reset the range based on those values.
+For example a valid step change.
+
 The deadband value can be specified as a fixed number, or a percentage. E.g. 10
 or 5% . If % mode is used then the output will only get sent if the input payload
 value is equal or more than the specified % away from the previously sent value.

function/rbe/locales/en-US/rbe.json

@@ -12,7 +12,9 @@
         "opts": {
             "rbe": "block unless value changes",
             "deadband": "block unless value changes by more than",
-            "narrowband": "block if value changes by more than"
+            "narrowband": "block if value changes by more than",
+            "in": "compared to last input value",
+            "out": "compared to last valid output value"
         },
         "warn": {
             "nonumber": "no number found in payload"

function/rbe/package.json

@@ -1,6 +1,6 @@
 {
     "name"          : "node-red-node-rbe",
-    "version"       : "0.1.4",
+    "version"       : "0.1.5",
     "description"   : "A Node-RED node that provides report-by-exception (RBE) and deadband capability.",
     "dependencies"  : {
     },

function/rbe/rbe.html

@@ -25,7 +25,11 @@
     </div>
     <div class="form-row" id="node-bandgap">
         <label for="node-input-gap">&nbsp;</label>
-        <input type="text" id="node-input-gap" data-i18n="[placeholder]rbe.placeholder.bandgap" style="width:71%;">
+        <input type="text" id="node-input-gap" data-i18n="[placeholder]rbe.placeholder.bandgap" style="width:70px;">
+        <select type="text" id="node-input-inout" style="width:55%;">
+            <option value="out" data-i18n="rbe.opts.out"></option>
+            <option value="in" data-i18n="rbe.opts.in"></option>
+        </select>
     </div>
     <div class="form-row" id="node-startvalue">
         <label for="node-input-start"><i class="fa fa-thumb-tack"/> <span data-i18n="rbe.label.start"></span></label>
@@ -43,11 +47,14 @@
     different to the previous one - <b>rbe</b> mode. This works on numbers, strings, and simple objects.</p>
     <p>Or it can block until the value changes by a specified amount - <b>deadband</b> mode.</p>
     <p>In deadband mode the incoming payload must contain a parseable <i>number</i> and is
-    output only if greater than + or - the <i>band gap</i> away from the previous output.</p>
+    output only if greater than + or - the <i>band gap</i> away from a previous value.</p>
     <p>Deadband also supports % - only sends if the input differs by more than x% of the original value.</p>
     <p>It can also ignore outlier values - <b>narrowband</b> mode.</p>
     <p>In narrowband mode the incoming payload is blocked if it is more than + or - the band gap
     away from the previous value. Useful for ignoring outliers from a faulty sensor for example.</p>
+    <p>Both Deadband and Narrowband allow comparison against either the <i>previous valid output value</i>, thus
+    ignoring any values out of range; or the <i>previous input value</i>, which resets the set point, thus allowing
+    gradual drift (deadband), or a step change (narrowband).</p>
     <p><b>Note:</b> This works on a per <code>msg.topic</code> basis. This means that a single rbe node can
     handle multiple topics at the same time.</p>
 </script>
@@ -60,7 +67,8 @@
             name: {value:""},
             func: {value:"rbe"},
             gap: {value:"",validate:RED.validators.regex(/^(\d*[.]*\d*|)(%|)$/)},
-            start: {value:""}
+            start: {value:""},
+            inout: {value:"out"}
         },
         inputs:1,
         outputs:1,
@@ -73,6 +81,9 @@
         },
         oneditprepare: function() {
             //$( "#node-input-gap" ).spinner({min:0});
+            if ($("#node-input-inout").val() === null) {
+                $("#node-input-inout").val("out");
+            }
             $("#node-input-func").on("change",function() {
                 if ($("#node-input-func").val() === "rbe") {
                     $("#node-bandgap").hide();

function/rbe/rbe.js

@@ -21,6 +21,7 @@ module.exports = function(RED) {
         this.func = n.func || "rbe";
         this.gap = n.gap || "0";
         this.start = n.start || '';
+        this.inout = n.inout || "out";
         this.pc = false;
         if (this.gap.substr(-1) === "%") {
             this.pc = true;
@@ -59,16 +60,17 @@ module.exports = function(RED) {
                         if (!node.previous.hasOwnProperty(t)) { node.previous[t] = n - node.gap; }
                         if (Math.abs(n - node.previous[t]) >= node.gap) {
                             if (this.func === "deadband") {
-                                node.previous[t] = n;
+                                if (node.inout === "out") { node.previous[t] = n; }
                                 node.send(msg);
                             }
                         }
                         else {
                             if (this.func === "narrowband") {
-                                node.previous[t] = n;
+                                if (node.inout === "out") { node.previous[t] = n; }
                                 node.send(msg);
                             }
                         }
+                        if (node.inout === "in") { node.previous[t] = n; }
                     }
                     else {
                         node.warn(RED._("rbe.warn.nonumber"));

test/function/rbe/rbe_spec.js

@@ -197,4 +197,28 @@ describe('rbe node', function() {
         });
     });
 
+        it('should not send output if more than x away from original value (narrowband in step mode)', function(done) {
+        var flow = [{"id":"n1", "type":"rbe", func:"narrowband", gap:"10", inout:"in", start:"500", wires:[["n2"]] },
+            {id:"n2", type:"helper"} ];
+        helper.load(testNode, flow, function() {
+            var n1 = helper.getNode("n1");
+            var n2 = helper.getNode("n2");
+            var c = 0;
+            n2.on("input", function(msg) {
+                if (c === 0) {
+                    msg.should.have.a.property("payload", 55);
+                }
+                else if (c === 1) {
+                    msg.should.have.a.property("payload", 205);
+                    done();
+                }
+                c += 1;
+            });
+            n1.emit("input", {payload:50});
+            n1.emit("input", {payload:55});
+            n1.emit("input", {payload:200});
+            n1.emit("input", {payload:205});
+        });
+    });
+
 });