Add a QmlExpression::error() method

QmlExpression should not print errors itself.  This is the responsibility
of the caller.

8 files changed, 107 insertions, 21 deletions

diff --git a/src/declarative/qml/qmlbinding.cpp b/src/declarative/qml/qmlbinding.cpp
index 65ff789..ab4343c 100644
--- a/src/declarative/qml/qmlbinding.cpp
+++ b/src/declarative/qml/qmlbinding.cpp
@@ -128,10 +128,12 @@ void QmlBinding::update(QmlMetaProperty::WriteFlags flags)
                                   idx, a);
 
         } else {
-            bool undefined = false;
-            QVariant value = this->value(&undefined);
+            bool isUndefined = false;
+            QVariant value = this->value(&isUndefined);
 
-            if (!undefined && data->property.object() && !data->property.write(value, flags)) {
+            if (this->hasError()) {
+                qWarning().nospace() << qPrintable(this->error().toString());
+            } else if (!isUndefined && data->property.object() && !data->property.write(value, flags)) {
                 QString fileName = data->fileName;
                 int line = data->line;
                 if (fileName.isEmpty()) fileName = QLatin1String("<Unknown File>");
diff --git a/src/declarative/qml/qmlboundsignal.cpp b/src/declarative/qml/qmlboundsignal.cpp
index ce591e8..d715309 100644
--- a/src/declarative/qml/qmlboundsignal.cpp
+++ b/src/declarative/qml/qmlboundsignal.cpp
@@ -175,8 +175,11 @@ int QmlBoundSignal::qt_metacall(QMetaObject::Call c, int id, void **a)
 {
     if (c == QMetaObject::InvokeMetaMethod && id == evaluateIdx) {
         if (m_params) m_params->setValues(a);
-        if (m_expression)
+        if (m_expression) {
             QmlExpressionPrivate::get(m_expression)->value(m_params);
+            if (m_expression->hasError())
+                qWarning().nospace() << qPrintable(m_expression->error().toString());
+        }
         if (m_params) m_params->clearValues();
         return -1;
     } else {
diff --git a/src/declarative/qml/qmlcontext.cpp b/src/declarative/qml/qmlcontext.cpp
index 2ebdf10..5032ff4 100644
--- a/src/declarative/qml/qmlcontext.cpp
+++ b/src/declarative/qml/qmlcontext.cpp
@@ -77,8 +77,11 @@ void QmlContextPrivate::addScript(const QString &script, QObject *scopeObject,
 
     QScriptValue val = scriptEngine->evaluate(script, fileName, lineNumber);
 
-    if (scriptEngine->hasUncaughtException()) 
-        QmlExpressionPrivate::printException(scriptEngine);
+    if (scriptEngine->hasUncaughtException()) {
+        QmlError error;
+        QmlExpressionPrivate::exceptionToError(scriptEngine, error);
+        qWarning().nospace() << qPrintable(error.toString());
+    }
 
     scriptEngine->popContext();
 
diff --git a/src/declarative/qml/qmlerror.cpp b/src/declarative/qml/qmlerror.cpp
index 514fe44..f4c9580 100644
--- a/src/declarative/qml/qmlerror.cpp
+++ b/src/declarative/qml/qmlerror.cpp
@@ -70,7 +70,7 @@ QmlErrorPrivate::QmlErrorPrivate()
     Create an empty error object.
 */
 QmlError::QmlError()
-: d(new QmlErrorPrivate)
+: d(0)
 {
 }
 
@@ -78,7 +78,7 @@ QmlError::QmlError()
     Create a copy of \a other.
 */
 QmlError::QmlError(const QmlError &other)
-: d(new QmlErrorPrivate)
+: d(0)
 {
     *this = other;
 }
@@ -88,10 +88,16 @@ QmlError::QmlError(const QmlError &other)
 */
 QmlError &QmlError::operator=(const QmlError &other)
 {
-    d->url = other.d->url;
-    d->description = other.d->description;
-    d->line = other.d->line;
-    d->column = other.d->column;
+    if (!other.d) {
+        delete d;
+        d = 0;
+    } else {
+        if (!d) d = new QmlErrorPrivate;
+        d->url = other.d->url;
+        d->description = other.d->description;
+        d->line = other.d->line;
+        d->column = other.d->column;
+    }
     return *this;
 }
 
@@ -104,11 +110,20 @@ QmlError::~QmlError()
 }
 
 /*!
+    Return true if this error is valid, otherwise false.
+*/
+bool QmlError::isValid() const
+{
+    return d != 0;
+}
+
+/*!
     Return the url for the file that caused this error.
 */
 QUrl QmlError::url() const
 {
-    return d->url;
+    if (d) return d->url;
+    else return QUrl();
 }
 
 /*!
@@ -116,6 +131,7 @@ QUrl QmlError::url() const
 */
 void QmlError::setUrl(const QUrl &url)
 {
+    if (!d) d = new QmlErrorPrivate;
     d->url = url;
 }
 
@@ -124,7 +140,8 @@ void QmlError::setUrl(const QUrl &url)
 */
 QString QmlError::description() const
 {
-    return d->description;
+    if (d) return d->description;
+    else return QString();
 }
 
 /*!
@@ -132,6 +149,7 @@ QString QmlError::description() const
 */
 void QmlError::setDescription(const QString &description)
 {
+    if (!d) d = new QmlErrorPrivate;
     d->description = description;
 }
 
@@ -140,7 +158,8 @@ void QmlError::setDescription(const QString &description)
 */
 int QmlError::line() const
 {
-    return d->line;
+    if (d) return d->line;
+    else return -1;
 }
 
 /*!
@@ -148,6 +167,7 @@ int QmlError::line() const
 */
 void QmlError::setLine(int line)
 {
+    if (!d) d = new QmlErrorPrivate;
     d->line = line;
 }
 
@@ -156,7 +176,8 @@ void QmlError::setLine(int line)
 */
 int QmlError::column() const
 {
-    return d->column;
+    if (d) return d->column;
+    else return -1;
 }
 
 /*!
@@ -164,6 +185,7 @@ int QmlError::column() const
 */
 void QmlError::setColumn(int column)
 {
+    if (!d) d = new QmlErrorPrivate;
     d->column = column;
 }
 
diff --git a/src/declarative/qml/qmlerror.h b/src/declarative/qml/qmlerror.h
index c1a8720..ee3d7b4 100644
--- a/src/declarative/qml/qmlerror.h
+++ b/src/declarative/qml/qmlerror.h
@@ -61,6 +61,8 @@ public:
     QmlError &operator=(const QmlError &);
     ~QmlError();
 
+    bool isValid() const;
+
     QUrl url() const;
     void setUrl(const QUrl &);
     QString description() const;
diff --git a/src/declarative/qml/qmlexpression.cpp b/src/declarative/qml/qmlexpression.cpp
index c62756b..8231bf8 100644
--- a/src/declarative/qml/qmlexpression.cpp
+++ b/src/declarative/qml/qmlexpression.cpp
@@ -260,7 +260,8 @@ QVariant QmlExpressionPrivate::evalSSE()
     return rv;
 }
 
-void QmlExpressionPrivate::printException(QScriptEngine *scriptEngine)
+void QmlExpressionPrivate::exceptionToError(QScriptEngine *scriptEngine, 
+                                            QmlError &error)
 {
     if (scriptEngine->hasUncaughtException() && 
         scriptEngine->uncaughtException().isError()) {
@@ -277,8 +278,12 @@ void QmlExpressionPrivate::printException(QScriptEngine *scriptEngine)
             fileName = QLatin1String("<Unknown File>");
         }
 
-        qWarning().nospace() << qPrintable(fileName) << ":" << lineNumber << ": "
-                             << qPrintable(exception.toString());
+        error.setUrl(QUrl(fileName));
+        error.setLine(lineNumber);
+        error.setColumn(-1);
+        error.setDescription(exception.toString());
+    } else {
+        error = QmlError();
     }
 }
 
@@ -321,10 +326,13 @@ QVariant QmlExpressionPrivate::evalQtScript(QObject *secondaryScope, bool *isUnd
     if (isUndefined)
         *isUndefined = svalue.isUndefined() || scriptEngine->hasUncaughtException();
 
+    // Handle exception
     if (scriptEngine->hasUncaughtException()) {
-       printException(scriptEngine);
+       exceptionToError(scriptEngine, data->error);
        scriptEngine->clearExceptions();
        return QVariant();
+    } else {
+        data->error = QmlError();
     }
 
     if (secondaryScope) {
@@ -418,6 +426,8 @@ QVariant QmlExpressionPrivate::value(QObject *secondaryScope, bool *isUndefined)
 
     \a isUndefined is set to true if the expression resulted in an
     undefined value.
+
+    \sa hasError(), error()
 */
 QVariant QmlExpression::value(bool *isUndefined)
 {
@@ -509,6 +519,43 @@ QObject *QmlExpression::scopeObject() const
     return d->data->me;
 }
 
+/*!
+    Returns true if the last call to value() resulted in an error, 
+    otherwise false.
+    
+    \sa error(), clearError()
+*/
+bool QmlExpression::hasError() const
+{
+    Q_D(const QmlExpression);
+    return d->data->error.isValid();
+}
+
+/*!
+    Clear any expression errors.  Calls to hasError() following this will
+    return false.
+
+    \sa hasError(), error()
+*/
+void QmlExpression::clearError()
+{
+    Q_D(QmlExpression);
+    d->data->error = QmlError();
+}
+
+/*!
+    Return any error from the last call to value().  If there was no error,
+    this returns an invalid QmlError instance.
+
+    \sa hasError(), clearError()
+*/
+
+QmlError QmlExpression::error() const
+{
+    Q_D(const QmlExpression);
+    return d->data->error;
+}
+
 /*! \internal */
 void QmlExpression::__q_notify()
 {
diff --git a/src/declarative/qml/qmlexpression.h b/src/declarative/qml/qmlexpression.h
index 96694d6..127d3f3 100644
--- a/src/declarative/qml/qmlexpression.h
+++ b/src/declarative/qml/qmlexpression.h
@@ -44,6 +44,7 @@
 
 #include <QtCore/qobject.h>
 #include <QtCore/qvariant.h>
+#include <QtDeclarative/qmlerror.h>
 
 QT_BEGIN_HEADER
 
@@ -82,6 +83,10 @@ public:
 
     QObject *scopeObject() const;
 
+    bool hasError() const;
+    void clearError();
+    QmlError error() const;
+
 public Q_SLOTS:
     QVariant value(bool *isUndefined = 0);
 
diff --git a/src/declarative/qml/qmlexpression_p.h b/src/declarative/qml/qmlexpression_p.h
index 3ec8d1c..b453a96 100644
--- a/src/declarative/qml/qmlexpression_p.h
+++ b/src/declarative/qml/qmlexpression_p.h
@@ -92,6 +92,8 @@ public:
     bool expressionRewritten:1;
     QScriptValue expressionFunction;
 
+    QmlError error;
+
     QmlBasicScript sse;
     QObject *me;
     bool trackChange;
@@ -151,7 +153,7 @@ public:
         return static_cast<QmlExpressionPrivate *>(QObjectPrivate::get(expr));
     }
 
-    static void printException(QScriptEngine *);
+    static void exceptionToError(QScriptEngine *, QmlError &);
 };
 
 QT_END_NAMESPACE