[Cppcms-users] json_rpc and json questions

[Daniel V. <chi...@gm...>]

Hello,

Question 1.

I am implementing a json rpc server (cppcms::rpc::json_rpc_server) with
privileges.

One possible solution is for each rpc method do the following:

void my_rpc_server::get_sensible_data()
{
	if ( check_privileges() ) {

		// method implementation		
		//...
	}
	else {
		return_error("not authorized");
	}	
};

The problem is that I think this solution is not good because I would
like to decouple the privilege system of the rpc methods definitions.

Another theoretical solution would be extend virtual main method to add
desired pre actions:

class my_rcp : public cppcms::rpc::json_rpc_server
{
	virtual void main(std::string);
};


void main(std::string //unused)
{
	json_rpc_request req = parse_json_rpc_request(context()); // Ideally
this method should be protected and implemented in json_rpc_server.

	// Added pre actions

	if ( check_privileges(req.method_name) )
	{
		dispatch_request(req);   // Ideally this method should be protected
and implemented in json_rpc_server.
	}
	else {
		return_error("not authorised");
	}
}


AFAIK that is not posible with current json_rpc_server implementation. 

What is the best approach to add pre actions (ie: check privileges) to 
rpc method invocation?.

Question 2.

I can't implement a json rpc method with a json::value argument, for
example the following example not compile:

void my_rpc_server::my_method(cppcms::json::value v)
{
}

One posible workaround is define a json::value to json::value trait:

namespace cppcms { namespace json {
    template<>
    struct traits<value> {               
        static value get(value const &v) {                   
            return v;      
        }                   
        static void set(value &v,value const &in) {                   
            v = in;          
        }                   
    };
}} // end cppcms::json

But I guest it is not optimal because nedless copy overhead.

Thank you.