path: root/src/declarative/qml/qdeclarativeerror.cpp

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#include "qdeclarativeerror.h"

#include <QtCore/qdebug.h>
#include <QtCore/qfile.h>
#include <QtCore/qstringlist.h>

QT_BEGIN_NAMESPACE

/*!
    \class QDeclarativeError
    \since 4.7
    \brief The QDeclarativeError class encapsulates a QML error.

    QDeclarativeError includes a textual description of the error, as well
    as location information (the file, line, and column). The toString()
    method creates a single-line, human-readable string containing all of
    this information, for example:
    \code
    file:///home/user/test.qml:7:8: Invalid property assignment: double expected
    \endcode

    You can use qDebug() or qWarning() to output errors to the console. This method
    will attempt to open the file indicated by the error
    and include additional contextual information.
    \code
    file:///home/user/test.qml:7:8: Invalid property assignment: double expected
            y: "hello"
               ^
    \endcode

    \sa QDeclarativeView::errors(), QDeclarativeComponent::errors()
*/
class QDeclarativeErrorPrivate
{
public:
    QDeclarativeErrorPrivate();

    QUrl url;
    QString description;
    int line;
    int column;
};

QDeclarativeErrorPrivate::QDeclarativeErrorPrivate()
: line(-1), column(-1)
{
}

/*!
    Creates an empty error object.
*/
QDeclarativeError::QDeclarativeError()
: d(0)
{
}

/*!
    Creates a copy of \a other.
*/
QDeclarativeError::QDeclarativeError(const QDeclarativeError &other)
: d(0)
{
    *this = other;
}

/*!
    Assigns \a other to this error object.
*/
QDeclarativeError &QDeclarativeError::operator=(const QDeclarativeError &other)
{
    if (!other.d) {
        delete d;
        d = 0;
    } else {
        if (!d) d = new QDeclarativeErrorPrivate;
        d->url = other.d->url;
        d->description = other.d->description;
        d->line = other.d->line;
        d->column = other.d->column;
    }
    return *this;
}

/*!
    \internal
*/
QDeclarativeError::~QDeclarativeError()
{
    delete d; d = 0;
}

/*!
    Returns true if this error is valid, otherwise false.
*/
bool QDeclarativeError::isValid() const
{
    return d != 0;
}

/*!
    Returns the url for the file that caused this error.
*/
QUrl QDeclarativeError::url() const
{
    if (d) return d->url;
    else return QUrl();
}

/*!
    Sets the \a url for the file that caused this error.
*/
void QDeclarativeError::setUrl(const QUrl &url)
{
    if (!d) d = new QDeclarativeErrorPrivate;
    d->url = url;
}

/*!
    Returns the error description.
*/
QString QDeclarativeError::description() const
{
    if (d) return d->description;
    else return QString();
}

/*!
    Sets the error \a description.
*/
void QDeclarativeError::setDescription(const QString &description)
{
    if (!d) d = new QDeclarativeErrorPrivate;
    d->description = description;
}

/*!
    Returns the error line number.
*/
int QDeclarativeError::line() const
{
    if (d) return d->line;
    else return -1;
}

/*!
    Sets the error \a line number.
*/
void QDeclarativeError::setLine(int line)
{
    if (!d) d = new QDeclarativeErrorPrivate;
    d->line = line;
}

/*!
    Returns the error column number.
*/
int QDeclarativeError::column() const
{
    if (d) return d->column;
    else return -1;
}

/*!
    Sets the error \a column number.
*/
void QDeclarativeError::setColumn(int column)
{
    if (!d) d = new QDeclarativeErrorPrivate;
    d->column = column;
}

/*!
    Returns the error as a human readable string.
*/
QString QDeclarativeError::toString() const
{
    QString rv;
    QUrl u(url());
    if (u.isEmpty()  || (u.isLocalFile() && u.path().isEmpty()))
        rv = QLatin1String("<Unknown File>");
    else
        rv = u.toString();

    if (line() > 0) {
        rv += QLatin1Char(':') + QString::number(line());
        if (column() != -1)
            rv += QLatin1Char(':') + QString::number(column());
    }

    rv += QLatin1String(": ") + description();

    return rv;
}

/*!
    \relates QDeclarativeError
    \fn QDebug operator<<(QDebug debug, const QDeclarativeError &error)

    Outputs a human readable version of \a error to \a debug.
*/

QDebug operator<<(QDebug debug, const QDeclarativeError &error)
{
    debug << error.toString().toUtf8().constData();

    QUrl url = error.url();

    if (error.line() > 0 && url.scheme() == QLatin1String("file")) {
        QString file = url.toLocalFile();
        QFile f(file);
        if (f.open(QIODevice::ReadOnly)) {
            QByteArray data = f.readAll();
            QTextStream stream(data, QIODevice::ReadOnly);
#ifndef QT_NO_TEXTCODEC
            stream.setCodec("UTF-8");
#endif
            const QString code = stream.readAll();
            const QStringList lines = code.split(QLatin1Char('\n'));

            if (lines.count() >= error.line()) {
                const QString &line = lines.at(error.line() - 1);
                debug << "\n    " << qPrintable(line);

                if(error.column() > 0) {
                    int column = qMax(0, error.column() - 1);
                    column = qMin(column, line.length());

                    QByteArray ind;
                    ind.reserve(column);
                    for (int i = 0; i < column; ++i) {
                        const QChar ch = line.at(i);
                        if (ch.isSpace())
                            ind.append(ch.unicode());
                        else
                            ind.append(' ');
                    }
                    ind.append('^');
                    debug << "\n    " << ind.constData();
                }
            }
        }
    }
    return debug;
}

QT_END_NAMESPACE