124 lines
2.8 KiB
C++
124 lines
2.8 KiB
C++
#include <iostream>
|
|
#include <iomanip>
|
|
#include <sstream>
|
|
#include <nlohmann/json.hpp>
|
|
|
|
using json = nlohmann::json;
|
|
|
|
// a simple event consumer that collects string representations of the passed
|
|
// values; not inheriting from json::json_sax_t is not required, but can
|
|
// help not to forget a required function
|
|
class sax_event_consumer : public json::json_sax_t
|
|
{
|
|
public:
|
|
std::vector<std::string> events;
|
|
|
|
bool null() override
|
|
{
|
|
events.push_back("value: null");
|
|
return true;
|
|
}
|
|
|
|
bool boolean(bool val) override
|
|
{
|
|
events.push_back("value: " + std::string(val ? "true" : "false"));
|
|
return true;
|
|
}
|
|
|
|
bool number_integer(number_integer_t val) override
|
|
{
|
|
events.push_back("value: " + std::to_string(val));
|
|
return true;
|
|
}
|
|
|
|
bool number_unsigned(number_unsigned_t val) override
|
|
{
|
|
events.push_back("value: " + std::to_string(val));
|
|
return true;
|
|
}
|
|
|
|
bool number_float(number_float_t val, const string_t& s) override
|
|
{
|
|
events.push_back("value: " + s);
|
|
return true;
|
|
}
|
|
|
|
bool string(string_t& val) override
|
|
{
|
|
events.push_back("value: " + val);
|
|
return true;
|
|
}
|
|
|
|
bool start_object(std::size_t elements) override
|
|
{
|
|
events.push_back("start: object");
|
|
return true;
|
|
}
|
|
|
|
bool end_object() override
|
|
{
|
|
events.push_back("end: object");
|
|
return true;
|
|
}
|
|
|
|
bool start_array(std::size_t elements) override
|
|
{
|
|
events.push_back("start: array");
|
|
return true;
|
|
}
|
|
|
|
bool end_array() override
|
|
{
|
|
events.push_back("end: array");
|
|
return true;
|
|
}
|
|
|
|
bool key(string_t& val) override
|
|
{
|
|
events.push_back("key: " + val);
|
|
return true;
|
|
}
|
|
|
|
bool parse_error(std::size_t position, const std::string& last_token, const json::exception& ex) override
|
|
{
|
|
events.push_back("error: " + std::string(ex.what()));
|
|
return false;
|
|
}
|
|
};
|
|
|
|
int main()
|
|
{
|
|
// a JSON text
|
|
auto text = R"(
|
|
{
|
|
"Image": {
|
|
"Width": 800,
|
|
"Height": 600,
|
|
"Title": "View from 15th Floor",
|
|
"Thumbnail": {
|
|
"Url": "http://www.example.com/image/481989943",
|
|
"Height": 125,
|
|
"Width": 100
|
|
},
|
|
"Animated" : false,
|
|
"IDs": [116, 943, 234, 38793],
|
|
"Distance": 12.723374634
|
|
}
|
|
}
|
|
)";
|
|
|
|
// create a SAX event consumer object
|
|
sax_event_consumer sec;
|
|
|
|
// parse and serialize JSON
|
|
bool result = json::sax_parse(text, &sec);
|
|
|
|
// output the recorded events
|
|
for (auto& event : sec.events)
|
|
{
|
|
std::cout << "(" << event << ") ";
|
|
}
|
|
|
|
// output the result of sax_parse
|
|
std::cout << "\nresult: " << std::boolalpha << result << std::endl;
|
|
}
|