mirror of
https://github.com/nlohmann/json
synced 2024-12-05 09:31:04 +00:00
125 lines
2.8 KiB
C++
125 lines
2.8 KiB
C++
#include <iostream>
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#include <iomanip>
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#include <sstream>
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#include <nlohmann/json.hpp>
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using json = nlohmann::json;
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// a simple event consumer that collects string representations of the passed
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// values; not inheriting from json::json_sax_t is not required, but can
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// help not to forget a required function
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class sax_event_consumer : public json::json_sax_t
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{
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public:
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std::vector<std::string> events;
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bool null() override
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{
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events.push_back("value: null");
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return true;
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}
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bool boolean(bool val) override
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{
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events.push_back("value: " + std::string(val ? "true" : "false"));
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return true;
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}
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bool number_integer(number_integer_t val) override
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{
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events.push_back("value: " + std::to_string(val));
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return true;
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}
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bool number_unsigned(number_unsigned_t val) override
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{
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events.push_back("value: " + std::to_string(val));
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return true;
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}
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bool number_float(number_float_t val, const string_t& s) override
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{
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events.push_back("value: " + s);
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return true;
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}
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bool string(string_t& val) override
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{
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events.push_back("value: " + val);
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return true;
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}
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bool start_object(std::size_t elements) override
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{
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events.push_back("start: object");
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return true;
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}
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bool end_object() override
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{
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events.push_back("end: object");
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return true;
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}
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bool start_array(std::size_t elements) override
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{
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events.push_back("start: array");
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return true;
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}
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bool end_array() override
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{
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events.push_back("end: array");
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return true;
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}
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bool key(string_t& val) override
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{
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events.push_back("key: " + val);
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return true;
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}
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bool parse_error(std::size_t position, const std::string& last_token, const json::exception& ex) override
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{
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events.push_back("error: " + std::string(ex.what()));
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return false;
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}
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};
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int main()
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{
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// a JSON text
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auto text = R"(
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{
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"Image": {
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"Width": 800,
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"Height": 600,
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"Title": "View from 15th Floor",
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"Thumbnail": {
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"Url": "http://www.example.com/image/481989943",
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"Height": 125,
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"Width": 100
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},
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"Animated" : false,
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"IDs": [116, 943, 234, 38793],
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"Distance": 12.723374634
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}
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}
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)";
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// create a SAX event consumer object
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sax_event_consumer sec;
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// parse and serialize JSON
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bool result = json::sax_parse(text, &sec);
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// output the recorded events
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for (auto& event : sec.events)
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{
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std::cout << "(" << event << ") ";
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}
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// output the result of sax_parse
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std::cout << "\nresult: " << std::boolalpha << result << std::endl;
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}
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