+ json loading methods

json/json_functions.h

@@ -260,6 +260,38 @@ template <typename T> bool loadjson(const jsonval& parent, std::string key, T& i
     return true;
 }
 
+static bool loadjson(const std::map<std::string, std::string>& parent, const std::string& key, svalue<std::string>& value, const bool exist = true)
+{
+    std::map<std::string, std::string>::const_iterator itr;
+
+    bool* loaded = nullptr;
+    if (!extract_value(parent, key, exist, loaded, itr)) {
+        return false;
+    }
+
+    value.set(itr->second);
+
+    return true;
+}
+
+static bool loadjson(const jsonval& parent, const std::string& key, svalue<std::string>& value, const bool exist = true)
+{
+    jsonval::ConstMemberIterator itr;
+
+    bool* loaded = nullptr;
+    if (!extract_value(parent, key, exist, loaded, itr)) {
+        return false;
+    }
+
+    if (!itr->value.IsString()) {
+        throw (Exp() << "element '" << key << "'" << " has unexpected format '");
+    }
+
+    value.set(itr->value.GetString());
+
+    return true;
+}
+
 template <typename T> static bool loadjson(const jsonval& parent, const std::string& key, svalue<T>& value, const bool exist = true)
 {
     jsonval::ConstMemberIterator itr;
@@ -356,7 +388,7 @@ static bool loadjson(const jsonval& parent, const std::string& key, double& valu
     }
     else if (a.IsString()) {
 
-        std::string str = a.GetString();
+        const std::string str = a.GetString();
         if (str.empty() && !exist) {
             if (loaded) {
                 *loaded = false;
@@ -389,7 +421,7 @@ static bool loadjson(const jsonval& parent, const std::string& key, float& value
     }
     else if (a.IsString()) {
 
-        std::string str = a.GetString();
+        const std::string str = a.GetString();
         if (str.empty() && !exist) {
             if (loaded) {
                 *loaded = false;