Improved errir for handling for parsed expression values, issue #2

Corrected device-config-schema: "unit", "label", and "discrete" are now optional as described in README, issue #2
Removed "type" property from example in README, issue #2

README.md

@@ -51,7 +51,6 @@ Note, however, the resulting value must be a number to be processed by the filte
             "label": "Temperature",
             "expression": "$unipi-2.temperature",
             "acronym": "T",
-            "type": "number",
             "unit": "°C"
         }
     }
@@ -82,7 +81,6 @@ Note, however, the resulting value must be a number to be processed by the filte
             "name": "Temperature",
             "expression": "$unipi-2.temperature",
             "acronym": "T",
-            "type": "number",
             "unit": "°C"
         }
     }

device-config-schema.coffee

@@ -25,14 +25,17 @@ module.exports = {
           unit:
             description: "The unit of the variable. Only works if type is a number."
             type: "string"
+            required: false
           label:
             description: "A custom label to use in the frontend."
             type: "string"
+            required: false
           discrete:
             description: "
                 Should be set to true if the value does not change continuously over time.
                 "
             type: "boolean"
+            required: false
           acronym:
             description: "Acronym to show as value label in the frontend"
             type: "string"
@@ -63,14 +66,17 @@ module.exports = {
           unit:
             description: "The unit of the variable. Only works if type is a number."
             type: "string"
+            required: false
           label:
             description: "A custom label to use in the frontend."
             type: "string"
+            required: false
           discrete:
             description: "
                 Should be set to true if the value does not change continuously over time.
                 "
             type: "boolean"
+            required: false
           acronym:
             description: "Acronym to show as value label in the frontend"
             type: "string"

filter.coffee

@@ -33,7 +33,7 @@ module.exports = (env) ->
       @sum = 0.0
       @mean = 0.0
 
-      @varManager = plugin.framework.variableManager #so you get the variableManager
+      @varManager = plugin.framework.variableManager
       @_exprChangeListeners = []
 
       name = @output.name
@@ -74,18 +74,15 @@ module.exports = (env) ->
             else
               assert false
         ).then((val) =>
-          if val?
-            val = Number(val)
-            @filterValues.push val
-            @sum = @sum + val
-            if @filterValues.length > @size
-              @sum = @sum - @filterValues.shift()
-            @mean = @sum / @filterValues.length
-
-            env.logger.debug @mean, @filterValues
-            @_setAttribute name, @mean
-          else
-            env.logger.error "Error on device #{@config.id}: Input value is null or undefined"
+          val = @_getNumber(val)
+          @filterValues.push val
+          @sum = @sum + val
+          if @filterValues.length > @size
+            @sum = @sum - @filterValues.shift()
+          @mean = @sum / @filterValues.length
+
+          env.logger.debug @mean, @filterValues
+          @_setAttribute name, @mean
 
           return @attributeValue
         ).catch((error) =>
@@ -94,6 +91,17 @@ module.exports = (env) ->
       )
       evaluate()
 
+    _getNumber: (value) ->
+      if value?
+        numValue = Number value
+        unless isNaN numValue
+          return numValue
+        else
+        errorMessage = "Input value is not a number: #{value}"
+      else
+        errorMessage = "Input value is null or undefined"
+      throw new Error errorMessage
+
     _setAttribute: (attributeName, value) ->
       @attributeValue = value
       @emit attributeName, value
@@ -150,24 +158,21 @@ module.exports = (env) ->
             else
               assert false
         ).then((val) =>
-          if val?
-            val = Number(val)
-            @filterValues.push val
-            if @filterValues.length > @size
-              @filterValues.shift()
+          val = @_getNumber(val)
+          @filterValues.push val
+          if @filterValues.length > @size
+            @filterValues.shift()
 
-            processedValues = _.clone(@filterValues)
-            if processedValues.length > 2
-              processedValues.sort()
-              processedValues.shift()
-              processedValues.pop()
+          processedValues = _.clone(@filterValues)
+          if processedValues.length > 2
+            processedValues.sort()
+            processedValues.shift()
+            processedValues.pop()
 
-            @mean = processedValues.reduce(((a, b) => return a + b), 0) / processedValues.length
+          @mean = processedValues.reduce(((a, b) => return a + b), 0) / processedValues.length
 
-            env.logger.debug @mean, @filterValues, processedValues
-            @_setAttribute name, @mean
-          else
-            env.logger.error "Error on device #{@config.id}: Input value is null or undefined"
+          env.logger.debug @mean, @filterValues, processedValues
+          @_setAttribute name, @mean
 
           return @attributeValue
         ).catch((error) =>
@@ -176,6 +181,17 @@ module.exports = (env) ->
       )
       evaluate()
 
+    _getNumber: (value) ->
+      if value?
+        numValue = Number value
+        unless isNaN numValue
+          return numValue
+        else
+        errorMessage = "Input value is not a number: #{value}"
+      else
+        errorMessage = "Input value is null or undefined"
+      throw new Error errorMessage
+
     _setAttribute: (attributeName, value) ->
       @attributeValue = value
       @emit attributeName, value