Json Parsing

[ChrisW67]

QJsonDocument, QJsonObject, QJsonArray

First you will need valid JSON data.

[Stephen28]

I was Learning qt. I am Parsing json values from https://countriesnow.space/api/v0.1/countries this api services. I am Parsing country values to one combo Box and If the Country is selected,add the cities name to another combo Box.

[Stephen28]

@jsulm can you share the link

[jsulm]

@Stephen28 said in Json Parsing:

can you share the link

What link?

[Christian Ehrlicher]

@jsulm said in Json Parsing:

What link?

The link where you wrote a class which manages the task to parse the above (invalid) json which was given to you? :-D

[JonB]

@Stephen28

@jsulm said in Json Parsing:

You need to iterate over the "data" array and for each entry there check the name of the country. If you found the object with country=Afganistan you can get the cities just like in the link above...

This is what you need to do. Just try to spell the country you want correctly, unlike @jsulm's response ;-)

[jsulm]

@JonB said in Json Parsing:

unlike @jsulm's response

Yeah, spelling/orthography was never my strength :-)

[JonB]

@jsulm
Don't give me that! How do you spell Afghanistan in German??

[jsulm]

@JonB Same. But the language doesn't matter: I'm not good at that :-) Not even in my native language.

[Stephen28]

@jsulm can u please help me with the code

[ChrisW67]

#include <QCoreApplication>
#include <QFile>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QJsonValue>
#include <QDebug>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QFile in("/tmp/test/test.json");
    if (in.open(QFile::ReadOnly)) {
        QByteArray json = in.readAll();

        QJsonParseError error;
        QJsonDocument doc = QJsonDocument::fromJson(json, &error);
        if (!doc.isNull()) {
            // We have valid JSON, but not necessarily a good response
            if (doc.isObject()) {
                QJsonObject top = doc.object();
                if (top.contains("error")) {
                    QJsonValue errorValue = top.value("error");
                    if (errorValue.isBool() && !errorValue.toBool(true)) {

                        // Find Afghanistan (assuming the structure is as expected)
                        QJsonArray dataArray = top.value("data").toArray();
                        for (auto dataEntry: dataArray) {
                            if (dataEntry.isObject()) {
                                QJsonObject countryObject = dataEntry.toObject();
                                // no error checking in next few lines, but you really should
                                if (countryObject.value("country").toString() == QStringLiteral("Afghanistan")) {
                                    QJsonArray cityArray = countryObject.value("cities").toArray();
                                    for (auto cityValue: cityArray) {
                                        qDebug() << cityValue.toString();
                                    }
                                }
                            }
                        }

                    }
                }
            }

        }
        else {
            qDebug() << error.errorString();
        }
    }
    return a.exec();
}

[Stephen28]

@ChrisW67 can't able to use bool check for json object.

[JonB]

@Stephen28 What does this mean, what are you referring to in the code?