Add Config write-only option

The "AuthorizationKey" config is specified as write-only and thus, may be updated by the server but not reported through the GetConfiguration option.

Author: Matthias Akstaller

src/MicroOcpp/Core/ConfigurationKeyValue.cpp

@@ -75,11 +75,27 @@ bool Configuration::isRebootRequired() {
 }
 
 void Configuration::setReadOnly() {
-    readOnly = true;
+    if (mutability == Mutability::ReadWrite) {
+        mutability = Mutability::ReadOnly;
+    } else {
+        mutability = Mutability::None;
+    }
 }
 
 bool Configuration::isReadOnly() {
-    return readOnly;
+    return mutability == Mutability::ReadOnly;
+}
+
+bool Configuration::isReadable() {
+    return mutability == Mutability::ReadWrite || mutability == Mutability::ReadOnly;
+}
+
+void Configuration::setWriteOnly() {
+    if (mutability == Mutability::ReadWrite) {
+        mutability = Mutability::WriteOnly;
+    } else {
+        mutability = Mutability::None;
+    }
 }
 
 /*

src/MicroOcpp/Core/ConfigurationKeyValue.h

@@ -36,7 +36,15 @@ class Configuration {
     revision_t value_revision = 0; //write access counter; used to check if this config has been changed
 private:
     bool rebootRequired = false;
-    bool readOnly = false;
+
+    enum class Mutability : uint8_t {
+        ReadWrite,
+        ReadOnly,
+        WriteOnly,
+        None
+    };
+    Mutability mutability = Mutability::ReadWrite;
+
 public:
     virtual ~Configuration();
 
@@ -60,6 +68,9 @@ class Configuration {
 
     void setReadOnly();
     bool isReadOnly();
+    bool isReadable();
+
+    void setWriteOnly();
 };
 
 /*

src/MicroOcpp/Operations/GetConfiguration.cpp

@@ -40,6 +40,9 @@ std::unique_ptr<JsonDoc> GetConfiguration::createConf(){
                     MO_DBG_ERR("invalid config");
                     continue;
                 }
+                if (!container->getConfiguration(i)->isReadable()) {
+                    continue;
+                }
                 configurations.push_back(container->getConfiguration(i));
             }
         }
@@ -53,7 +56,7 @@ std::unique_ptr<JsonDoc> GetConfiguration::createConf(){
                 }
             }
 
-            if (res) {
+            if (res && res->isReadable()) {
                 configurations.push_back(res);
             } else {
                 unknownKeys.push_back(key.c_str());