Update node-red-random to add option to dynamically pass in 'To' and 'From' (#707)

* Add option to dynamically pass in 'From' and 'To' - fixed bug when 'From' was greater than 'To' by flipping the two

* Set initial values of 'From' and 'To to "" to allow dynamic overriding them

function/random/README.md

@@ -19,4 +19,6 @@ If set to return an integer it can include both the low and high values.
 If set to return a floating point value it will be from the low value, up to, but
 **not** including the high value. `min <= n < max` - so selecting 1 to 6 will return values 1 <= n < 6 .
 
+You can dynamically pass in the 'From' and 'To' values to the node using msg.to and/or msg.from. **NOTE:** hard coded values in the node **always take precedence**.
+
 **Note:** This returns numbers - objects of type **number**.

function/random/locales/en-US/random.html

@@ -1,7 +1,14 @@
 <script type="text/html" data-help-name="random">
-    <p>Generates a random number between a low and high value.</p>
+    <p>Generates a random number between a low and high value. Defaults to 1 to 10.</p>
     <p>If set to return an integer it can <i>include</i> both the low and high values.
     <code>min <= n <= max</code></p>
     <p>If set to return a floating point value it will be from the low value, up to, but
     not including the high value. <code>min <= n < max</code></p>
+    <p><b>Inputs</b></p>
+    <p>You can dynamically pass in the 'From' and 'To' values to the node. <b>NOTE:</b> hard coded values in the node <b>always take precedence.</b>
+    <ul>
+    <i><b>From</b> [msg.from] Number containing the low value to be used.</i>
+    <br>
+    <i><b>To</b> [msg.to] Number containing the high value to be used.</i>
+    </ul>
 </script>

function/random/random.html

@@ -31,8 +31,8 @@
         color:"#E2D96E",
         defaults: {
             name: {value:""},
-            low: {value:"1"},
-            high: {value:"10"},
+            low:  {value: 1,validate:function(v) { return  !isNaN(v) || v.length === 0;} },
+            high: {value: 10,validate:function(v) { return  !isNaN(v) || v.length === 0;} },
             inte: {value:"true"},
             property: {value:"payload",required:true}
         },

function/random/random.js

@@ -3,21 +3,73 @@ module.exports = function(RED) {
     "use strict";
     function RandomNode(n) {
         RED.nodes.createNode(this,n);
-        this.low = Number(n.low || 1);
-        this.high = Number(n.high || 10);
+
+        this.low = n.low
+        this.high = n.high
         this.inte = n.inte || false;
         this.property = n.property||"payload";
         var node = this;
+        var tmp = {};
+
         this.on("input", function(msg) {
-            var value;
-            if (node.inte == "true" || node.inte === true) {
-                value = Math.round(Math.random() * (node.high - node.low + 1) + node.low - 0.5);
-            }
-            else {
-                value = Math.random() * (node.high - node.low) + node.low;
-            }
-            RED.util.setMessageProperty(msg,node.property,value);
-            node.send(msg);
+
+          tmp.low = 1                 // set this as the default low value
+          tmp.low_e = ""
+          if (node.low) {             // if the the node has a value use it
+              tmp.low = node.low
+          } else if ('from' in msg) { // else see if a 'from' is in the msg
+              if (Number(msg.from)) { // if it is, and is a number, use it
+                  tmp.low = Number(msg.from);
+              } else {                // otherwise setup NaN error
+                  tmp.low = NaN;
+                  tmp.low_e = " From: " + msg.from; // setup to show bad incoming msg.from
+              }
+          } 
+              
+          tmp.high = 10               // set this as the default high value  
+          tmp.high_e = "";
+          if (node.high) {            // if the the node has a value use it 
+              tmp.high = node.high
+          } else if ('to' in msg) {   // else see if a 'to' is in the msg
+              if (Number(msg.to)) {   // if it is, and is a number, use it
+                  tmp.high = Number(msg.to);
+              } else {                // otherwise setup NaN error 
+                  tmp.high = NaN
+                  tmp.high_e = " To: " + msg.to // setup to show bad incoming msg.to
+              }
+          } 
+                           
+          // if tmp.low or high are not numbers, send an error msg with bad values
+          if ( (isNaN(tmp.low)) || (isNaN(tmp.high)) ) {
+              this.error("Random: one of the input values is not a number. " + tmp.low_e + tmp.high_e);
+          } else {
+          // at this point we have valid values so now to generate the random number! 
+
+             // flip the values if low > high so random will work
+             var value = 0;
+             if (tmp.low > tmp.high) {  
+                 value = tmp.low
+                 tmp.low = tmp.high
+                 tmp.high = value
+             }
+
+             // if returning an integer, do a math.ceil() on the low value and a 
+             // Math.floor()high value before generate the random number. This must be 
+             // done to insure the rounding doesn't round up if using something like 4.7
+             // which would end up with 5
+             if ( (node.inte == "true") || (node.inte === true) ) {
+                 tmp.low  = Math.ceil(tmp.low);
+                 tmp.high = Math.floor(tmp.high);
+                 // use this to round integers
+                 value = Math.round(Math.random() * (tmp.high - tmp.low + 1) + tmp.low - 0.5);
+             } else {
+                 // use this to round floats
+                 value = (Math.random() * (tmp.high - tmp.low)) + tmp.low;
+             }
+            
+             RED.util.setMessageProperty(msg,node.property,value);
+             node.send(msg);
+          }
         });
     }
     RED.nodes.registerType("random",RandomNode);