CODEWITHSUNDEEP
c++jsonrapidjson
Raymond Kalonji
Raymond Kalonji

Reputation: 345

Rapidjson Iterating over and Getting Values of Complex JSON Object Members

I have the following JSON object

{  
   "prog":[  
      {  
         "iUniqueID":1,
         "bGroup":1,
         "inFiles":[  
            {  
               "sFileType":"Zonal Data 1",
               "bScenarioSpecific":0,
               "pos":{  
                  "x1":1555,
                  "y1":-375,
                  "x2":1879,
                  "y2":-432
               }
            },
            {  
               "sFileType":"Record File",
               "bScenarioSpecific":0,
               "pos":{  
                  "x1":1555,
                  "y1":-436,
                  "x2":1879,
                  "y2":-493
               }
            }
         ],
         "outFiles":[  
            {  
               "sFileType":"Record File 1",
               "bScenarioSpecific":1,
               "pos":{  
                  "x1":2344,
                  "y1":-405,
                  "x2":2662,
                  "y2":-462
               }
            }
         ]
      },
      {  
         "iUniqueID":2,
         "bGroup":1,
         "inFiles":[  
            {  
               "sFileType":"Matrix File 1",
               "bScenarioSpecific":0,
               "pos":{  
                  "x1":98,
                  "y1":-726,
                  "x2":422,
                  "y2":-783
               }
            },
            {  
               "sFileType":"Matrix File 2",
               "bScenarioSpecific":0,
               "pos":{  
                  "x1":98,
                  "y1":-787,
                  "x2":422,
                  "y2":-844
               }
            }
         ],
         "outFiles":[  
            {  
               "sFileType":"Record File 1",
               "bScenarioSpecific":1,
               "pos":{  
                  "x1":887,
                  "y1":-966,
                  "x2":1205,
                  "y2":-1023
               }
            }
         ]
      }
   ]
}

How can I iteratively access the x1 of objects inside "inFiles"? Or in general, how can I access the values stored in sub-array and sub-objects using rapidjson. Here is what I have so far

const Value& prog = document["prog"];

assert(prog.IsArray());

for (rapidjson::Value::ConstValueIterator itr = prog.Begin(); itr != prog.End(); ++itr) {

}

I have tried a variety of things but my code does not compile, therefore I felt like it would need be productive to add it to the description of the issue.

Upvotes: 2

Views: 8892

Answers (3)

Rabbid76
Rabbid76

Reputation: 210878

If you want to iterate through the properties of an object, you can use a Range-based for loop on rapidjson::Object or rapidjson::ConstObject:

if (value.IsObject()) {
    for (auto &item : value.GetObject()) {
        std::string propertyKey = item.name.GetString();
        auto &propertyValue = item.value;

        // [...]
    }
}

Upvotes: 0

Raymond Kalonji
Raymond Kalonji

Reputation: 345

Here is what ended up working

const Value& prog = d["prog"];
for (Value::ConstValueIterator p = prog.Begin(); p != prog.End(); ++p) {
    std:cout << (*p)["iUniqueID"].GetInt();
    const Value& inFiles = (*p)["inFiles"];
    for (Value::ConstValueIterator inFile = inFiles.Begin(); inFile != prog.End(); ++inFile) {
        std::cout << (*inFile)["sFileType"].GetString() << std::endl;
        std::cout << (*inFile)["pos"]["x1"].GetInt() << std::endl;
    }
}

The post here helped tremendously.

Upvotes: 3

Wander3r
Wander3r

Reputation: 1881

Here is a way you can iterate over the subarrays inside each array. Using ranged-for loop instead of iterator. 

rapidjson::Document doc;
doc.Parse(str); //the one shown in the question


for (auto const& p : doc["prog"].GetArray()) {
    std::cout << p["iUniqueID"].GetInt() << std::endl;
    for (auto const& in : p["inFiles"].GetArray()) {
        std::cout << in["sFileType"].GetString() << std::endl;
        std::cout << in["pos"]["x1"].GetInt() << std::endl;
    }
}

Hope this helps.

Upvotes: 2

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