sandbox/jsontest.cpp

   1 #include <string>
   2 #include <sstream>
   3 #include <json/json.h>
   4
   5 class Myexcept : public std::exception
   6 {
   7 public:
   8     Myexcept(std::string message)
   9             : message(message){};
  10     ~Myexcept() throw(){};
  11     const char* what() const throw()
  12     {
  13         return message.c_str();
  14     }
  15 private:
  16     std::string message;
  17 };
  18
  19 int main()
  20 {
  21     std::string json = "{\"batchcomplete\":\"\",\"query\":{\"normalized\":[{\"from\":\"Amundsen_Basin\",\"to\":\"Amundsen Basin\"}],\"pages\":{\"37082520\":{\"pageid\":37082520,\"ns\":0,\"title\":\"Amundsen Basin\",\"links\":[{\"ns\":0,\"title\":\"Abyssal\"},{\"ns\":0,\"title\":\"Arctic\"},{\"ns\":0,\"title\":\"Arctic Ocean\"},{\"ns\":0,\"title\":\"Cenozoic\"},{\"ns\":0,\"title\":\"Eurasian Basin\"},{\"ns\":0,\"title\":\"Gakkel Ridge\"},{\"ns\":0,\"title\":\"Lomonosov Ridge\"},{\"ns\":0,\"title\":\"Nansen Basin\"},{\"ns\":0,\"title\":\"Roald Amundsen\"},{\"ns\":0,\"title\":\"Seafloor spreading\"},{\"ns\":0,\"title\":\"Wilkes Basin\"}]}}}}";
  22     Json::Reader reader;
  23     Json::Value document;
  24
  25     // this works
  26     ////std::istringstream jsondatastream(json);
  27     ////jsondatastream >> document;
  28
  29     // this, too
  30     // this gives better error reporting?
  31     bool success = reader.parse(json, document, false);
  32
  33     if(!success) {
  34         throw Myexcept("Error parsing JSON");
  35     }
  36
  37     bool needmoredata = !document.isMember("batchcomplete");
  38     //! TODO: fetch more
  39
  40     auto next = document.get("query", Json::Value::nullSingleton());
  41
  42     if (next == Json::Value::nullSingleton()) {
  43         throw Myexcept("Error parsing JSON - no query result");
  44     }
  45
  46     next = next.get("pages", Json::Value::nullSingleton());
  47
  48     if (next == Json::Value::nullSingleton()) {
  49         throw Myexcept("Error parsing JSON - no pages result");
  50     }
  51 }