From 79fe7d684c44586fe47667c60110271367ba6591 Mon Sep 17 00:00:00 2001
From: Dave Conway-Jones <conway@uk.ibm.com>
Date: Mon, 4 Feb 2019 16:35:42 +0000
Subject: [PATCH] Add parsed JSON output option to MQTT subscribe node

---
 .../@node-red/nodes/core/io/10-mqtt.html          |  1 +
 .../@node-red/nodes/core/io/10-mqtt.js            | 15 +++++++++++----
 .../@node-red/nodes/locales/en-US/messages.json   |  7 +++++--
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/packages/node_modules/@node-red/nodes/core/io/10-mqtt.html b/packages/node_modules/@node-red/nodes/core/io/10-mqtt.html
index 6ba1dd4b1..274447e30 100644
--- a/packages/node_modules/@node-red/nodes/core/io/10-mqtt.html
+++ b/packages/node_modules/@node-red/nodes/core/io/10-mqtt.html
@@ -34,6 +34,7 @@
             <option value="auto" data-i18n="mqtt.output.auto"></option>
             <option value="buffer" data-i18n="mqtt.output.buffer"></option>
             <option value="utf8" data-i18n="mqtt.output.string"></option>
+            <option value="json" data-i18n="mqtt.output.json"></option>
             <option value="base64" data-i18n="mqtt.output.base64"></option>
         </select>
     </div>
diff --git a/packages/node_modules/@node-red/nodes/core/io/10-mqtt.js b/packages/node_modules/@node-red/nodes/core/io/10-mqtt.js
index f50195844..83132130d 100644
--- a/packages/node_modules/@node-red/nodes/core/io/10-mqtt.js
+++ b/packages/node_modules/@node-red/nodes/core/io/10-mqtt.js
@@ -399,16 +399,23 @@ module.exports = function(RED) {
             if (this.topic) {
                 node.brokerConn.register(this);
                 this.brokerConn.subscribe(this.topic,this.qos,function(topic,payload,packet) {
-                    if (node.datatype =="buffer") {
+                    if (node.datatype === "buffer") {
                         // payload = payload;
-                    } else if (node.datatype =="base64") {
+                    } else if (node.datatype === "base64") {
                         payload = payload.toString('base64');
-                    } else if (node.datatype =="utf8") {
+                    } else if (node.datatype === "utf8") {
                         payload = payload.toString('utf8');
+                    } else if (node.datatype === "json") {
+                        if (isUtf8(payload)) {
+                            payload = payload.toString();
+                            try { payload = JSON.parse(payload); }
+                            catch(e) { node.error(RED._("mqtt.errors.invalid-json-parse"),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; }
+                        }
+                        else { node.error((RED._("mqtt.errors.invalid-json-string")),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; }
                     } else {
                         if (isUtf8(payload)) { payload = payload.toString(); }
                     }
-                    var msg = {topic:topic,payload:payload, qos: packet.qos, retain: packet.retain};
+                    var msg = {topic:topic, payload:payload, qos:packet.qos, retain:packet.retain};
                     if ((node.brokerConn.broker === "localhost")||(node.brokerConn.broker === "127.0.0.1")) {
                         msg._topic = topic;
                     }
diff --git a/packages/node_modules/@node-red/nodes/locales/en-US/messages.json b/packages/node_modules/@node-red/nodes/locales/en-US/messages.json
index 59b39160d..8d2ba84cf 100644
--- a/packages/node_modules/@node-red/nodes/locales/en-US/messages.json
+++ b/packages/node_modules/@node-red/nodes/locales/en-US/messages.json
@@ -353,7 +353,8 @@
             "buffer": "a Buffer",
             "string": "a String",
             "base64": "a Base64 encoded string",
-            "auto": "auto-detect"
+            "auto": "auto-detect (string or buffer)",
+            "json": "a parsed JSON object"
         },
         "true": "true",
         "false": "false",
@@ -362,7 +363,9 @@
             "not-defined": "topic not defined",
             "missing-config": "missing broker configuration",
             "invalid-topic": "Invalid topic specified",
-            "nonclean-missingclientid": "No client ID set, using clean session"
+            "nonclean-missingclientid": "No client ID set, using clean session",
+            "invalid-json-string": "Invalid JSON string",
+            "invalid-json-parse": "Failed to parse JSON string"
         }
     },
     "httpin": {