Change JSON MIME type to application/json (me-no-dev#311)

Author: merlinschumacher

README.md

@@ -717,7 +717,7 @@ This way of sending Json is great for when the result is below 4KB
 #include "ArduinoJson.h"
 
 
-AsyncResponseStream *response = request->beginResponseStream("text/json");
+AsyncResponseStream *response = request->beginResponseStream("application/json");
 DynamicJsonBuffer jsonBuffer;
 JsonObject &root = jsonBuffer.createObject();
 root["heap"] = ESP.getFreeHeap();
@@ -1126,7 +1126,7 @@ server.on("/scan", HTTP_GET, [](AsyncWebServerRequest *request){
     }
   }
   json += "]";
-  request->send(200, "text/json", json);
+  request->send(200, "application/json", json);
   json = String();
 });
 ```

src/AsyncJson.h

@@ -57,7 +57,7 @@ class AsyncJsonResponse: public AsyncAbstractResponse {
   public:
     AsyncJsonResponse(bool isArray=false): _isValid{false} {
       _code = 200;
-      _contentType = "text/json";
+      _contentType = "application/json";
       if(isArray)
         _root = _jsonBuffer.createArray();
       else

src/SPIFFSEditor.cpp

@@ -477,7 +477,7 @@ void SPIFFSEditor::handleRequest(AsyncWebServerRequest *request){
       dir.close();
 #endif
       output += "]";
-      request->send(200, "text/json", output);
+      request->send(200, "application/json", output);
       output = String();
     }
     else if(request->hasParam("edit") || request->hasParam("download")){

src/WebResponses.cpp

@@ -483,7 +483,7 @@ void AsyncFileResponse::_setContentType(const String& path){
   if (path.endsWith(".html")) _contentType = "text/html";
   else if (path.endsWith(".htm")) _contentType = "text/html";
   else if (path.endsWith(".css")) _contentType = "text/css";
-  else if (path.endsWith(".json")) _contentType = "text/json";
+  else if (path.endsWith(".json")) _contentType = "application/json";
   else if (path.endsWith(".js")) _contentType = "application/javascript";
   else if (path.endsWith(".png")) _contentType = "image/png";
   else if (path.endsWith(".gif")) _contentType = "image/gif";