backend.cpp

#include "backend.h"

Backend::Backend(QQuickItem *parent) : QObject(parent) {
    engine.load(QUrl(QStringLiteral("qrc:///main.qml")));

    mainWindow = engine.rootObjects().value(0);
    lvList = mainWindow->findChild<QObject*>("lvList");
    btnRequest = mainWindow->findChild<QObject*>("btnRequest");

    engine.rootContext()->setContextProperty("backend", this);

    namRequest = new QNetworkAccessManager(this);
    connect(namRequest, SIGNAL(finished(QNetworkReply*)), this, SLOT(slotRequestFinished(QNetworkReply*)));
}

void Backend::makeRequest(int id) {
    btnRequest->setProperty("enabled", "false");

    QString prepareRequest("https://api.vk.com/method/friends.get?user_id=" + QString::number(id) +
                           "&order=hints&count=500&fields=photo_50");
    qDebug(prepareRequest.toUtf8());
    QNetworkRequest request(QUrl(prepareRequest.toUtf8()));
    namRequest->get(request);
}

void Backend::slotRequestFinished(QNetworkReply * reply) {
    if (reply->error() != QNetworkReply::NoError) {
        qDebug(reply->errorString().toUtf8());
    } else {
        QJsonDocument jsonDoc = QJsonDocument::fromJson(reply->readAll()); //Документ
        QJsonObject jsonObj;
        QJsonValue jsonVal;
        QJsonArray jsonArr;
        int count;

        jsonObj = jsonDoc.object();

        if (!jsonObj.isEmpty()) {
            jsonVal = jsonObj.value("count");
            if (!jsonVal.isNull()) {
                count = jsonVal.toInt();
            }
        }

        jsonArr = jsonDoc.object().value("items").toArray();
        QMetaObject::invokeMethod(lvList, "clear");
        for (int i=0; i<jsonArr.size(); i++) {
            QVariantMap map;
            QJsonObject fri;
            fri = jsonArr[i];

            QString photo50 = fri.value("photo_50").toString();
            QString name = fri.value("first_name").toString() + fri.value("last_name").toString();

            map.insert("lvImage", photo50);
            map.insert("lvLabel", name);

            QMetaObject::invokeMethod(lvList, "append", Q_ARG(QVariant, QVariant::fromValue(map)));
        }
    }

    btnRequest->setProperty("enabled", "true");

    reply->deleteLater();
}