feat: parse value functions #739 (#741)

README.md

@@ -357,6 +357,8 @@ The Gateway values table can be used with all gateway types to customize specifi
 - **Post operation**: If you want to convert your value (eg. '/10' '/100' '*10' '*100')
 - **Poll**: Enable this to set the value `enablePoll` flag
 - **Verify Changes**: Used to verify changes of this values
+- **Parse Send**: Enable this to allow users to specify a custom `function(value)` to parse the value sent to MQTT. The function must be sync
+- **Parse receive**: Enable this to allow users to specify a custom `function(value)` to parse the value received via MQTT. The function must be sync
 
 ## :file_folder: Nodes Management
 

lib/Gateway.js

@@ -240,8 +240,17 @@ function onValueChanged (valueId, node, changed) {
   // Parse valueId value and create the payload
   var tmpVal = valueId.value
 
-  if (valueConf && isValidOperation(valueConf.postOperation)) {
-    tmpVal = eval(valueId.value + valueConf.postOperation)
+  if (valueConf) {
+    if (isValidOperation(valueConf.postOperation)) {
+      tmpVal = eval(valueId.value + valueConf.postOperation)
+    }
+
+    if (valueConf.parseSend) {
+      var parsedVal = evalFunction(valueConf.sendFunction, valueId, tmpVal)
+      if (parsedVal != null) {
+        tmpVal = parsedVal
+      }
+    }
   }
 
   // Check if I need to update discovery topics of this device
@@ -430,6 +439,28 @@ function isValidOperation (op) {
   return op && !/[^0-9.()\-+*/,]/g.test(op)
 }
 
+/**
+ * Evaluate the return value of a custom parse Function
+ *
+ * @param {String} code The function code
+ * @param {Object} valueId The valueId object
+ * @param {*} value The actual value to parse
+ * @returns
+ */
+function evalFunction (code, valueId, value) {
+  var result = null
+
+  try {
+    /* eslint-disable no-new-func */
+    var parseFunc = new Function('value', code)
+    result = parseFunc(value)
+  } catch (error) {
+    debug('Error eval function of value ', valueId.value_id, error.message)
+  }
+
+  return result
+}
+
 /**
  * Converts an integer to 2 digits hex number
  *
@@ -633,16 +664,29 @@ Gateway.prototype.parsePayload = function (payload, valueId, valueConf) {
       }
     }
 
-    if (valueConf && isValidOperation(valueConf.postOperation)) {
-      let op = valueConf.postOperation
+    if (valueConf) {
+      if (isValidOperation(valueConf.postOperation)) {
+        let op = valueConf.postOperation
+
+        // revert operation to write
+        if (op.includes('/')) op = op.replace(/\//, '*')
+        else if (op.includes('*')) op = op.replace(/\*/g, '/')
+        else if (op.includes('+')) op = op.replace(/\+/, '-')
+        else if (op.includes('-')) op = op.replace(/-/, '+')
 
-      // revert operation to write
-      if (op.includes('/')) op = op.replace(/\//, '*')
-      else if (op.includes('*')) op = op.replace(/\*/g, '/')
-      else if (op.includes('+')) op = op.replace(/\+/, '-')
-      else if (op.includes('-')) op = op.replace(/-/, '+')
+        payload = eval(payload + op)
+      }
 
-      payload = eval(payload + op)
+      if (valueConf.parseReceive) {
+        var parsedVal = evalFunction(
+          valueConf.receiveFunction,
+          valueId,
+          payload
+        )
+        if (parsedVal != null) {
+          payload = parsedVal
+        }
+      }
     }
   } catch (error) {
     debug('Error while parsing payload', payload, 'for valueID', valueId)

package.json

@@ -108,6 +108,7 @@
     "native-url": "^0.3.4",
     "nedb": "^1.8.0",
     "openzwave-shared": "^1.7.1",
+    "prismjs": "^1.21.0",
     "serialport": "^9.0.1",
     "serve-favicon": "^2.5.0",
     "socket.io": "^2.3.0",
@@ -116,6 +117,7 @@
     "uniqid": "^5.2.0",
     "vue": "^2.6.12",
     "vue-d3-network": "^0.1.28",
+    "vue-prism-editor": "^1.2.2",
     "vue-router": "^3.4.3",
     "vuetify": "^2.3.10",
     "vuex": "^3.5.1"

src/components/dialogs/DialogGatewayValue.vue

@@ -114,6 +114,50 @@
                   v-model="editedValue.verifyChanges"
                 ></v-switch>
               </v-flex>
+
+              <v-flex xs6>
+                <v-switch
+                  label="Parse send"
+                  hint="Create a function that parse the value sent via MQTT"
+                  persistent-hint
+                  v-model="editedValue.parseSend"
+                ></v-switch>
+              </v-flex>
+
+              <v-container v-if="editedValue.parseSend">
+                <p>
+                  Write the function here. Args are <code>value</code>. The
+                  function is sync and must return the parsed <code>value</code>
+                </p>
+                <prism-editor
+                  lineNumbers
+                  v-model="editedValue.sendFunction"
+                  language="js"
+                  :highlight="highlighter"
+                ></prism-editor>
+              </v-container>
+
+              <v-flex xs6>
+                <v-switch
+                  label="Parse receive"
+                  hint="Create a function that parse the received value from MQTT"
+                  persistent-hint
+                  v-model="editedValue.parseReceive"
+                ></v-switch>
+              </v-flex>
+
+              <v-container v-if="editedValue.parseReceive">
+                <p>
+                  Write the function here. Args are <code>value</code>. The
+                  function is sync and must return the parsed <code>value</code>
+                </p>
+                <prism-editor
+                  lineNumbers
+                  v-model="editedValue.receiveFunction"
+                  language="js"
+                  :highlight="highlighter"
+                ></prism-editor>
+              </v-container>
             </v-layout>
           </v-form>
         </v-container>
@@ -134,7 +178,20 @@
 </template>
 
 <script>
+// import Prism Editor
+import { PrismEditor } from 'vue-prism-editor'
+import 'vue-prism-editor/dist/prismeditor.min.css' // import the styles somewhere
+
+// import highlighting library (you can use any library you want just return html string)
+import { highlight, languages } from 'prismjs/components/prism-core'
+import 'prismjs/components/prism-clike'
+import 'prismjs/components/prism-javascript'
+import 'prismjs/themes/prism-tomorrow.css' // import syntax highlighting styles
+
 export default {
+  components: {
+    PrismEditor
+  },
   props: {
     value: Boolean,
     gw_type: Number,
@@ -220,9 +277,19 @@ export default {
     }
   },
   methods: {
+    highlighter (code) {
+      return highlight(code, languages.js) // returns html
+    },
     isSensor (v) {
       return v && (v.class_id === 0x31 || v.class_id === 0x32)
     }
   }
 }
 </script>
+
+<style>
+/* optional class for removing the outline */
+.prism-editor__textarea:focus {
+  outline: none;
+}
+</style>