Json array creation using boost c++

Question

I want to print the json array using below code snippet but it is not giving the desired result . Here is the output

{
    "prefix": "standard",
    "faceID": "42"
}

{
    "prefix1": "standard2",
    "faceID2": "44"
}

This is produced by below code snippet:

#include <boost/serialization/string.hpp>
#include <string>
#include <sstream>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/json_parser.hpp>
using boost::property_tree::ptree; 
using boost::property_tree::write_json;

void create_array(ptree parent)
{
    std::stringstream oss;

    write_json(oss,parent);

    std::string serialized_strings(oss.str());

    std::cout << oss.str() << std::endl;
}

int main()                                                                                                                                                                                                 
{   

    ptree pt,pt1;

    pt.put("prefix","standard");
    pt.put("faceID",42);
    create_array(pt);
    pt1.put("prefix1","standard2");
    pt1.put("faceID2",44);
    create_array(pt1); 

}

expected output:

[
{
    "prefix": "standard",
    "faceID": "42"
},

{
    "prefix1": "standard2",
    "faceID2": "44"
}
]

Please, searching can't be that hard, even if reading the ~20 lines of documentation is too much. — sehe, Sep 08 '17 at 20:26
Dear @sehe :I already went through that link and It looks like in boost there is no solution for this problem and i don't want to create the name of array for binding the elements so looking for alternate solution . — user2997518, Sep 09 '17 at 00:05
You do not "want" to what now? "Create the name"? Did you read about [the limitations in those lines of documentation](http://www.boost.org/doc/libs/1_65_1/doc/html/property_tree/parsers.html#property_tree.parsers.json_parser)? (link fixed) — sehe, Sep 09 '17 at 00:07
solution given in below link doesn't fulfill my requiremnt.https://stackoverflow.com/questions/2114466/creating-json-arrays-in-boost-using-property-trees — user2997518, Sep 09 '17 at 00:08

score 1 · Accepted Answer · answered Sep 09 '17 at 00:13

1

Just to make it absolutely clear:

The documentation states that

The property tree dataset is not typed, and does not support arrays as such. Thus, the following JSON / property tree mapping is used [...]

It continues to describe that each ptree represents a JSON object, always.

You need to remember that Boost Property Tree is not a JSON library. It is a Property Tree library, that optionally uses a subset of JSON for interoperability purposes. Therefore you cannot have arbitrary JSON things: You can not have a top-level arrays, you cannot have lone values, you cannot have actual numeric types, null, booleans etc.

You can only have Property Trees serialized using the described mappings.

answered Sep 09 '17 at 00:13

sehe

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I completely agree with you. i can understand that we can't have arbitrary json things with boost and that's why i had pointed out in my question that how to address this issue . should we go for other library to achieve this ? – user2997518 Sep 09 '17 at 00:24
Yes. (By the way, it was _not_ clear to me that you wanted the array at top-level, neither was it clear that you are solliciting advice for alternative tools. That question, by the way, would be off-topic for [SO]. I personally recommend http://rapidjson.org/md_doc_tutorial.html or https://github.com/nlohmann/json) – sehe Sep 09 '17 at 00:25
accepted this with +1 but not sure why my question is marked for downvote. if other than boost still solution is available in other library then suggestion should come. – user2997518 Sep 09 '17 at 00:33

Json array creation using boost c++

1 Answers1