Added and tweaked comms error display

Delete unreadable json files and re-download

Author: jsphuebner

data/index.html

@@ -58,6 +58,10 @@ <h2 id="large-modal-header"></h2>
 			</div>
 		</div>
 
+    <div id="communication-error-bar" class="communication-error-bar">
+			<p>Communication problem between ESP and STM</p>
+		</div>
+
 		<!-- 'Add CAN Mapping' modal -->
 		<div id="can-mapping-modal-overlay" class="modal-overlay">
 			<div id="can-mapping-modal-container" class="can-mapping-modal-container">

data/inverter.js

@@ -26,6 +26,7 @@
 var paramsCache = {
   data: undefined,
   dataById: {},
+  failedFetchCount: 0,
 
   get: function(name) {
     if ( paramsCache.data !== undefined )
@@ -77,6 +78,25 @@ var inverter = {
     {
       if (replyFunc) replyFunc(this.responseText);
     }
+    xmlhttp.onreadystatechange = function()
+    {
+      if (xmlhttp.readyState === XMLHttpRequest.DONE) {
+        console.log(req + ": " + xmlhttp.status);
+        if (xmlhttp.status != 200) {
+          paramsCache.failedFetchCount += 1;
+          if ( paramsCache.failedFetchCount >= 2 ){
+            ui.showCommunicationErrorBar();
+          }
+        }
+        else {
+          paramsCache.failedFetchCount = 0;
+        }
+        if ( paramsCache.failedFetchCount < 2 )
+        {
+          ui.hideCommunicationErrorBar();
+        }
+      }
+    }
 
     if (repeat)
       req += "&repeat=" + repeat;
@@ -104,6 +124,7 @@ var inverter = {
             inverter.firmwareVersion = parseFloat(param.value);
         }
       } catch(ex) {}
+
       paramsCache.setData(params);
       if (replyFunc) replyFunc(params);
     });

data/style.css

@@ -635,3 +635,24 @@ input:checked + .slider:before {
         width: 60px;
     }
 }
+
+/* notification bar */
+
+.communication-error-bar {
+    display: none;
+    padding: 15px;
+    background-color: #f44336;
+    color: white;
+    z-index: 100;
+    margin: 0 auto;
+    position: relative;
+    width: 30%;
+    top: 0px;
+    clear: left;
+    height: 20px;
+    border-radius: 0px 0px 20px 20px;
+}
+
+.communication-error-bar p {
+    text-align: center;
+}

data/ui.js

@@ -141,7 +141,6 @@ var ui = {
 		wifi.populateWiFiTab();
 		ui.populateFileList();
 		ui.refreshStatusBox();
-		ui.refreshMessagesBox();
 		ui.getNodeId();
 	},
 
@@ -150,7 +149,6 @@ var ui = {
 	{
 		ui.updateTables();
 		ui.refreshStatusBox();
-		ui.refreshMessagesBox();
 	},
 
 	getNodeId: function() {
@@ -391,6 +389,16 @@ var ui = {
       clearInterval(ui.autoRefreshHandle);
     }
 	},
+
+	/** @brief Show notification bar */
+	showCommunicationErrorBar: function() {
+		document.getElementById('communication-error-bar').style.display = 'block';
+	},
+
+	/** @brief Hide notification bar */
+	hideCommunicationErrorBar: function() {
+		document.getElementById('communication-error-bar').style.display = 'none';
+	},
 	/**
 	 * ~~~ DASHBOARD ~~~
 	 */

src/oi_can.cpp

@@ -332,9 +332,15 @@ void SendJson(WiFiClient client) {
   twai_message_t rxframe;
 
   File file = SPIFFS.open(jsonFileName, "r");
-  deserializeJson(doc, file);
+  auto result = deserializeJson(doc, file);
   file.close();
 
+  if (result != DeserializationError::Ok) {
+    SPIFFS.remove(jsonFileName); //if json file is invalid, remove it and trigger re-download
+    updstate == REQUEST_JSON;
+    return;
+  }
+
   JsonObject root = doc.as<JsonObject>();
 
   for (JsonPair kv : root) {