Iterate on json structure with Poco - c++

Question

I'm using Poco library for C++ code
Here is an example of the json tree I have to parse
{
"name" : "actionToDo",
"description" : "",
"version" : "1",
"parameters" : {
"inputDirectory" : "string",
"workingDir" : "string",
"tempDir" : "string",
"size" : "integer"
}
}
The amount of data into "parameters" field can change.
I have to put all items into a map
Here my code today
std:: map<std::string, std::string> output;
Poco::JSON::Parser sparser;
Poco::Dynamic::Var result = sparser.parse(jsonStr);
Poco::JSON::Object::Ptr object = result.extract<Poco::JSON::Object::Ptr>();
Poco::DynamicStruct ds = *object;
Poco::Dynamic::Var collection(ds["parameters"]);
if (collection.isStruct())
{
LOG("STRUCT"); //it's logged !!
}
for (Poco::Dynamic::VarIterator it = collection.begin(); it != collection.end(); ++it)
{
LOG_F("item : %s", it->toString()); //never logged
//here I would like to have something like
//output[it->first()] = it->second();
}
And the output I got
14:13:00'900 : : [Notice] : STRUCT
14:13:00'900 : : [Critical] : Exception : Exception: Unable to load Run from file :
/opt/.../file.json Exception:
Unable to parse field 'parameters' or its children
Invalid access: Not a struct.
The "Unable to parse field 'parameters' or its children" is generated by a catch below but the "Invalid access: Not a struct." comes from Poco

Answer 1

use for collection variable DynamicStruct instead of Var
Poco::DynamicStruct collection = ds["parameters"].extract<Poco::DynamicStruct>();
for (auto it = collection.begin(); it != collection.end(); ++it)
{
LOG_F("item : %s", it->second.toString().c_str());
}