Merge pull request #356 from kotl/master

Update suggested versions and manually merge connection error check

README.md

@@ -20,7 +20,9 @@ The Arduino library is [under heavy development](https://github.com/googlesample
 - [FirebaseArduino API Reference](http://firebase-arduino.readthedocs.io/)
 
 ## Dependencies
-- FirebaseArduino now depends on [ArduinoJson library](https://github.com/bblanchon/ArduinoJson) instead of containing it's own version of it. Please either use Library Manager or download specific version of the library from github.
+- FirebaseArduino now depends on [ArduinoJson library](https://github.com/bblanchon/ArduinoJson) instead of containing it's own version of it. Please either use Library Manager or download specific version of the library from github. We recommend that ArduinoJson is at least version [5.13.1](https://github.com/bblanchon/ArduinoJson/tree/v5.13.1)
+
+- ESP8266 Core SDK. We recommend using officially tagged releases and it should be at least [2.4.1](https://github.com/esp8266/Arduino/tree/2.4.1)
 
 ## Disclaimer
 

contrib/test/dummies/FirebaseHttpClient_dummy.cpp

@@ -23,6 +23,10 @@ class FirebaseHttpClientDummy : public FirebaseHttpClient {
   void addHeader(const std::string& UNUSED_ARG(name), const std::string& UNUSED_ARG(value)) override {
   }
 
+  bool connected() override {
+    return true;
+  }
+
   void collectHeaders(const char* UNUSED_ARG(header_keys[]), const int UNUSED_ARG(count)) override {
   }
 

src/FirebaseArduino.cpp

@@ -156,6 +156,11 @@ void FirebaseArduino::stream(const String& path) {
 
 bool FirebaseArduino::available() {
   if (stream_http_.get() == nullptr) {
+    error_ = FirebaseError(FIREBASE_ERROR_CODES::STREAM_NOT_INITIALIZED, "HTTP stream is not initialized");
+    return 0;
+  }
+  if (!stream_http_.get()->connected()) {
+    error_ = FirebaseError(FIREBASE_ERROR_CODES::HTTP_CONNECTION_LOST, "Connection Lost");
     return 0;
   }
   auto client = stream_http_.get()->getStreamPtr();

src/FirebaseError.h

@@ -1,6 +1,14 @@
 #ifndef firebase_error_h
 #define firebase_error_h
 
+
+// These error codes are used in addition to regular HTTP error codes.
+// Same error space is shared between HTTP errors and these values. 
+enum FIREBASE_ERROR_CODES {
+  HTTP_CONNECTION_LOST = -5,
+  STREAM_NOT_INITIALIZED = -6
+};
+
 class FirebaseError {
  public:
   // Make it explicit that the empty constructor mean no error.

src/FirebaseHttpClient.h

@@ -33,6 +33,8 @@ class FirebaseHttpClient {
 
   virtual std::string errorToString(int error_code) = 0;
 
+  virtual bool connected() = 0;
+
  protected:
   static const uint16_t kFirebasePort = 443;
 };

src/FirebaseHttpClient_Esp8266.cpp

@@ -83,6 +83,10 @@ class FirebaseHttpClientEsp8266 : public FirebaseHttpClient {
    return HTTPClient::errorToString(error_code).c_str();
   }
 
+  bool connected() override {
+    return http_.connected();
+  }
+
  private:
   ForceReuseHTTPClient http_;
 };