Add safeGetMember function to get a json member or null.

Jojo-1000 · Moritz Wirger
1 parent e9c64111
Showing 4 changed files with 38 additions and 12 deletions
hueplusplus/Hue.cpp
hueplusplus/HueLight.cpp
hueplusplus/Utils.cpp
hueplusplus/include/Utils.h
@@ -37,6 +37,7 @@
 #include "include/SimpleColorHueStrategy.h"
 #include "include/SimpleColorTemperatureStrategy.h"
 #include "include/UPnP.h"
+#include "include/Utils.h"
  
 HueFinder::HueFinder(std::shared_ptr<const IHttpHandler> handler) : http_handler(std::move(handler)) {}
  
@@ -180,10 +181,11 @@ std::string Hue::requestUsername(const std::string&amp; ip)
  
             if (answer.size() > 0)
             {
-                if (answer[0].count("success"))
+                nlohmann::json jsonUser = utils::safeGetMember(answer, 0, "success", "username");
+                if (jsonUser != nullptr)
                 {
                     // [{"success":{"username": "<username>"}}]
-                    username = answer[0]["success"]["username"];
+                    username = jsonUser;
                     this->ip = ip;
                     // Update commands with new username and ip
                     commands = HueCommandAPI(ip, port, username, http_handler);
@@ -290,8 +292,7 @@ HueLight&amp; Hue::getLight(int id)
 bool Hue::removeLight(int id)
 {
     nlohmann::json result = commands.DELETERequest("/lights/" + std::to_string(id), nlohmann::json::object());
-    bool success = result.is_array() && result.size() > 0 && result[0].count("success")
-        && result[0]["success"] == "/lights/" + std::to_string(id) + " deleted";
+    bool success = utils::safeGetMember(result, 0, "success") == "/lights/" + std::to_string(id) + " deleted";
     if (success && lights.count(id) != 0)
     {
         lights.erase(id);
@@ -132,8 +132,7 @@ bool HueLight::setName(const std::string&amp; name)
     nlohmann::json reply = SendPutRequest(request, "/name");
  
     // Check whether request was successful
-    return reply.size() > 0 && reply[0].count("success")
-        && reply[0]["success"]["/lights/" + std::to_string(id) + "/name"] == name;
+    return utils::safeGetMember(reply, 0, "success", "/lights/" + std::to_string(id) + "/name") == name;
 }
  
 ColorType HueLight::getColorType() const
@@ -235,7 +234,7 @@ void HueLight::refreshState()
     // std::chrono::steady_clock::now(); std::cout << "\tRefreshing lampstate of
     // lamp with id: " << id << ", ip: " << ip << "\n";
     nlohmann::json answer = commands.GETRequest("/lights/" + std::to_string(id), nlohmann::json::object());
-    if (answer.is_object() && answer.count("state"))
+    if (answer.count("state"))
     {
         state = answer;
     }
@@ -26,25 +26,25 @@
  
 namespace utils
 {
-    bool validateReplyForLight(nlohmann::json request, nlohmann::json reply, int lightId)
+    bool validateReplyForLight(const nlohmann::json& request, const nlohmann::json& reply, int lightId)
     {
         bool success = false;
         std::string path = "/lights/" + std::to_string(lightId) + "/state/";
-        for (nlohmann::json::iterator it = reply.begin(); it != reply.end(); ++it)
+        for (auto it = reply.begin(); it != reply.end(); ++it)
         {
             success = it.value().count("success");
             if (success)
             {
                 // Traverse through first object
                 nlohmann::json successObject = it.value()["success"];
-                for (nlohmann::json::iterator successIt = successObject.begin(); successIt != successObject.end();
+                for (auto successIt = successObject.begin(); successIt != successObject.end();
                      ++successIt)
                 {
                     const std::string successPath = successIt.key();
                     if (successPath.find(path) == 0)
                     {
                         const std::string valueKey = successPath.substr(path.size());
-                        nlohmann::json::iterator requestIt = request.find(valueKey);
+                        auto requestIt = request.find(valueKey);
                         success = requestIt != request.end();
                         if (success)
                         {
@@ -30,7 +30,33 @@ namespace utils
     //! \param reply The reply that was received
     //! \param lightId The identifier of the light
     //! \return True if request was executed correctly
-    bool validateReplyForLight(nlohmann::json request, nlohmann::json reply, int lightId);
+    bool validateReplyForLight(const nlohmann::json& request, const nlohmann::json& reply, int lightId);
+
+    //! \brief Returns the object/array member or null if it does not exist
+    template<typename... Paths>
+    nlohmann::json safeGetMember(const nlohmann::json& json, std::size_t index, Paths&&... otherPaths)
+    {
+        if (!json.is_array() || json.size() <= index)
+        {
+            return nullptr;
+        }
+        return safeGetMember(json[index], std::forward<Paths>(otherPaths)...);
+    }
+    template<typename KeyT, typename... Paths, 
+        std::enable_if_t<!std::is_integral<std::remove_reference_t<KeyT>>::value>* = nullptr>
+    nlohmann::json safeGetMember(const nlohmann::json& json, KeyT&& key, Paths&&... otherPaths)
+    {
+        auto memberIt = json.find(std::forward<KeyT>(key));
+        if (memberIt == json.end())
+        {
+            return nullptr;
+        }
+        return safeGetMember(*memberIt, std::forward<Paths>(otherPaths)...);
+    }
+    inline nlohmann::json safeGetMember(const nlohmann::json& json)
+    {
+        return json;
+    }
 } // namespace utils
  
 #endif
 \ No newline at end of file