ptree write_json does not conform to JSON standard

[Mark Pfeifer <Mark_Pfeifer@…>]

According to the JSON standard documented at ​http://www.json.org, only string values should have quotes around them. The Boost write_json method puts quotes around all values, not just strings.

For example, the following program:

#include <cstdlib> #include <string> #include <iostream> #include <boost/property_tree/ptree.hpp> #include <boost/property_tree/json_parser.hpp>

using boost::property_tree::ptree; using boost::property_tree::read_json; using boost::property_tree::write_json;

int main() {

ptree pt;

pt.put ("string", "string value"); pt.put ("integer", 1); pt.put ("float", 3.14159);

std::ostringstream buf; write_json (buf, pt);

std::cout << buf.str(); return 0;

}

produces this output:

{

"string": "string value", "integer": "1", "float": "3.14159"

}

According to the JSON standard, the output should be:

{

"string": "string value", "integer": 1, "float": 3.14159

}

(no quotes around the numeric values)

[Sebastian Redl]

ptree internally only has strings. put converts from the values you put in to strings, as get converts back. However, the tree itself only contains strings, and therefore so does the output JSON.

Making a ptree variant that preserves JSON types is a future plan, but far off.

[anonymous]

Yet no update after years..

[anonymous]

there should be some updates about this problem, or the boost json can only be used as reader not writer

[anonymous]

Still nothing???

[anonymous]

A conformant JSON writer should be in Boost since long ago. This ticket has been resolved as invalid, I can't believe it!

[anonymous]

rapidjson seems to do the job.

[anonymous]

rapidjson seems to do the job.

[anonymous]

No way this is invalid! Proper JSON parsing is absolutely necessary.

[rnistuk@…]

Here's my fix for numbers:

#include <string>
#include <boost/regex.hpp>

  std::string fix_json_numbers(const std::string &json_str)
    {
        boost::regex re("\\\"([0-9]+\\.{0,1}[0-9]*)\\\"");
        return  boost::regex_replace(json_str, re, "$1");
    }

And here's a unit test:

BOOST_AUTO_TEST_CASE(test_fix_json_str)
    {
        std::string json_str_in ="{\"cmd\":\"test\",\"data\":{\"integer\":\"283\",\"float\":\"34.433\"}";
        std::string json_str_accepted ="{\"cmd\":\"test\",\"data\":{\"integer\":283,\"float\":34.433}";
        std::string json_str_actual = fix_json_numbers(json_str_in);
        BOOST_CHECK_EQUAL(json_str_accepted, json_str_actual);
    }

NOTE: I've modified the unit test a bit to call the fix_json_numbers function directly, I have not compiled the unit test.

[anonymous]

This looks like a valid problem and still seen in 1.64. PLs look into this issue.

[anonymous]

Write value Str data = create_escapes(pt.template get_value<Str>()); stream << Ch('"') << data << Ch('"');

This might be the code to be examined.

[anonymous]

Yep, i just wanted to use it for with JSON, issue still exist in 1.65

[anonymous]

What a shame! This ticket is 4 years old!

[anonymous]

Ok, rapidjson it is.

[anonymous]

yup i was doing research today to pick a json parser and i stumbled upon this thing... indeed rapidjson it is!

[anonymous]

This is still an issue for 1.67. Odd that for such a trivial requirement, boost has a long-pending issue.

[anonymous]

This is huge shortcoming! This should at the very least be documented using a proper disclaimer in the JSON section...