qt-creator/src/plugins/mesonprojectmanager/mesoninfoparser/parsers/common.h

/****************************************************************************
**
** Copyright (C) 2020 Alexis Jeandet.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
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****************************************************************************/

#pragma once

#include <utils/optional.h>

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

namespace MesonProjectManager {
namespace Internal {

template<typename T>
inline T load(QJsonDocument &&doc);

template<>
inline QJsonArray load<QJsonArray>(QJsonDocument &&doc)
{
    return doc.array();
}

template<>
inline QJsonObject load<QJsonObject>(QJsonDocument &&doc)
{
    return doc.object();
}

template<typename T>
inline T load(const QJsonValueRef &ref);

template<>
inline QJsonArray load<QJsonArray>(const QJsonValueRef &ref)
{
    return ref.toArray();
}

template<>
inline QJsonObject load<QJsonObject>(const QJsonValueRef &ref)
{
    return ref.toObject();
}

template<typename T>
inline Utils::optional<T> load(const QString &jsonFile)
{
    QFile js(jsonFile);
    js.open(QIODevice::ReadOnly | QIODevice::Text);
    if (js.isOpen()) {
        auto data = js.readAll();
        return load<T>(QJsonDocument::fromJson(data));
    }
    return Utils::nullopt;
}

template<typename T>
inline Utils::optional<T> get(const QJsonObject &obj, const QString &name);

template<>
inline Utils::optional<QJsonArray> get<QJsonArray>(const QJsonObject &obj, const QString &name)
{
    if (obj.contains(name)) {
        auto child = obj[name];
        if (child.isArray())
            return child.toArray();
    }
    return Utils::nullopt;
}

template<>
inline Utils::optional<QJsonObject> get<QJsonObject>(const QJsonObject &obj, const QString &name)
{
    if (obj.contains(name)) {
        auto child = obj[name];
        if (child.isObject())
            return child.toObject();
    }
    return Utils::nullopt;
}

template<typename T, typename... Strings>
inline Utils::optional<T> get(const QJsonObject &obj, const QString &firstPath, const Strings &...path)
{
    if (obj.contains(firstPath))
        return get<T>(obj[firstPath].toObject(), path...);
    return Utils::nullopt;
}

} // namespace Internal
} // namespace MesonProjectManager