settings: add a callback to notify user of a settings change

examples/puara_basic_template/puara_basic_template.ino

@@ -6,9 +6,16 @@ Puara puara;
 // Dummy sensor data
 float sensor;
 
+void onPuaraSettingsChanged()
+{
+  // Process here any change of settings by the user, OSC port, etc.
+}
+
 void setup() {
   // put your setup code here, to run once:
     Serial.begin(115200);
+
+    puara.set_settings_changed_handler(onPuaraSettingsChanged);
       /*
      * the Puara start function initializes the filesystem, reads json configuration and
      * settings, start the wi-fi AP or connects to SSID, starts the webserver, inits serial 

src/puara.cpp

@@ -130,6 +130,11 @@ void Puara::write_settings_json()
   return g_puara.settings.write_settings_json();
 }
 
+void Puara::set_settings_changed_handler(std::function<void()> func)
+{
+  return g_puara.settings.set_settings_changed_handler(std::move(func));
+}
+
 double Puara::getVarNumber(std::string varName)
 {
   return g_puara.settings.getVarNumber(varName);

src/puara.h

@@ -12,6 +12,7 @@
 
 #include <string>
 #include <string_view>
+#include <functional>
 
 typedef void* httpd_handle_t;
 class Puara
@@ -50,6 +51,8 @@ class Puara
   void read_settings_json();
   void write_settings_json();
 
+  void set_settings_changed_handler(std::function<void()>);
+
   bool start_serial_listening();
   void send_serial_data(std::string data);
 

src/puara_filesystem.cpp

@@ -220,7 +220,6 @@ void JSONSettings::write_config_json()
 
 void JSONSettings::write_settings_json()
 {
-
   cJSON* root = cJSON_CreateObject();
   cJSON* settings = cJSON_CreateArray();
   cJSON* setting = NULL;
@@ -254,6 +253,13 @@ void JSONSettings::write_settings_json()
   LOG("write_settings_json: Delete json entity");
   cJSON_Delete(root);
 
+  if(this->on_settings_changed)
+    this->on_settings_changed();
+}
+
+void JSONSettings::set_settings_changed_handler(std::function<void()> func)
+{
+  this->on_settings_changed = std::move(func);
 }
 
 }

src/puara_filesystem.hpp

@@ -8,6 +8,7 @@
 
 #include <esp_err.h>
 
+#include <functional>
 #include <unordered_map>
 #include <vector>
 #include <string>
@@ -38,14 +39,18 @@ struct JSONSettings // TODO: remove from puara_filesystem
   void read_settings_json();
   void write_settings_json();
 
+  void set_settings_changed_handler(std::function<void()>);
+
   double getVarNumber(std::string varName);
   std::string getVarText(std::string varName);
 
   friend class Webserver;
   friend class Serial;
+
   // Private API used by puara_web
   std::vector<settingsVariables> variables;
   std::unordered_map<std::string, int> variables_fields;
+  std::function<void()> on_settings_changed;
 
   // Private API used by puara_serial
   void read_settings_json_internal(std::string& contents, bool merge = false);

src/puara_web.hpp

@@ -4,6 +4,7 @@
 
 #include <string>
 #include <unordered_map>
+#include <functional>
 
 typedef void* httpd_handle_t;
 struct httpd_req;