From 1f19f83863da1e2954c106045b3aa15b14a739cc Mon Sep 17 00:00:00 2001
From: Scott Bender <scott@scottbender.net>
Date: Thu, 2 Nov 2017 19:43:41 -0400
Subject: [PATCH] feature: add preferredSource to common fields

---
 schemas/definitions.json      |  3 +++
 scripts/processSchemaFiles.js |  4 ++--
 src/fullsignalk.js            | 14 +++++++++-----
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/schemas/definitions.json b/schemas/definitions.json
index c1f291fb7..6bdd86776 100644
--- a/schemas/definitions.json
+++ b/schemas/definitions.json
@@ -306,6 +306,9 @@
         },
         "sentence": {
           "type": "string"
+        },
+        "preferredSource": {
+          "type": "string"
         }
       }
     },
diff --git a/scripts/processSchemaFiles.js b/scripts/processSchemaFiles.js
index 76056f377..cde5fd685 100755
--- a/scripts/processSchemaFiles.js
+++ b/scripts/processSchemaFiles.js
@@ -146,7 +146,7 @@ class Parser {
           }
         }
 
-        const skipFields = ['timestamp', '$source', 'source', '_attr', 'meta', 'pgn', 'sentence', 'value', 'values']
+        const skipFields = ['timestamp', '$source', 'source', '_attr', 'meta', 'pgn', 'sentence', 'value', 'values', 'preferredSource']
         const embeddedFields =
           !this.tree[`${path}/timestamp`] ? {} :
             _.pick(subtree.properties ? _.omit(subtree.properties || {}, skipFields) : {}, (value, key) => {
@@ -212,7 +212,7 @@ class Parser {
      */
     .then(results => {
       const filenames = {}
-      const filter = ['/timestamp', '/$source', '/source', '/_attr', '/meta', '/pgn', '/sentence', '/value', '/values']
+      const filter = ['/timestamp', '/$source', '/source', '/_attr', '/meta', '/pgn', '/sentence', '/value', '/values', '/preferredSource']
 
       results.forEach(result => {
         filenames[result.name] = result.path
diff --git a/src/fullsignalk.js b/src/fullsignalk.js
index 34373a9dd..8a8d20d7d 100644
--- a/src/fullsignalk.js
+++ b/src/fullsignalk.js
@@ -220,11 +220,15 @@ function addValue(context, contextPath, source, timestamp, pathValue) {
     valueLeaf.values[sourceId].timestamp = timestamp;
     setMessage(valueLeaf.values[sourceId], source);
   }
-  assignValueToLeaf(pathValue.value, valueLeaf);
-  if (pathValue.path.length != 0) {
-    valueLeaf['$source'] = getId(source);
-    valueLeaf.timestamp = timestamp;
-    setMessage(valueLeaf, source);
+  var sourceId = getId(source);
+  if ( !valueLeaf.preferredSource || valueLeaf.preferredSource == sourceId )
+  {
+    assignValueToLeaf(pathValue.value, valueLeaf);
+    if (pathValue.path.length != 0) {
+      valueLeaf['$source'] = getId(source);
+      valueLeaf.timestamp = timestamp;
+      setMessage(valueLeaf, source);
+    }
   }
 }