--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qexternalvariableloader_p.h Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,139 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtXmlPatterns module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+// W A R N I N G
+// -------------
+//
+// This file is not part of the Qt API. It exists purely as an
+// implementation detail. This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+
+#ifndef Patternist_ExternalVariableLoader_H
+#define Patternist_ExternalVariableLoader_H
+
+#include "qitem_p.h"
+#include "qsequencetype_p.h"
+#include "qxmlname.h"
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+namespace QPatternist
+{
+ class DynamicContext;
+
+ /**
+ * @short Responsible for loading and declaring available external variables.
+ *
+ * An external variable in XQuery is a global variable that has been declared to receive
+ * its value from the XQuery implementation, as opposed to an initializing expression. Here
+ * is an example of a query with an external variable declaration, followed by a ordinary
+ * global variable:
+ *
+ * <tt> declare variable $theName external;
+ * declare variable $theName := "the value";
+ * "And here's the query body(a string literal)"</tt>
+ *
+ * An external variable declaration can also specify a sequence type:
+ *
+ * <tt>declare variable $theName as xs:integer external;</tt>
+ *
+ * This class allows the user to supply the values to external variables. When
+ * an external variable declaration occur in the query,
+ * announceExternalVariable() is called.
+ *
+ * @ingroup Patternist_xdm
+ * @author Frans Englich <frans.englich@nokia.com>
+ */
+ class Q_AUTOTEST_EXPORT ExternalVariableLoader : public QSharedData
+ {
+ public:
+ typedef QExplicitlySharedDataPointer<ExternalVariableLoader> Ptr;
+ inline ExternalVariableLoader() {}
+
+ virtual ~ExternalVariableLoader();
+
+ /**
+ * Called when Patternist encounters an external variable in the query. It is guaranteed
+ * to be called once for each external variable appearing in a query module.
+ *
+ * @param name the name of the variable. Quaranteed to never be @c null.
+ * @param declaredType the type that the user declared the variable to be of. Whether
+ * this type matches the actual value of the variable or not is irrelevant. Patternist
+ * will do the necessary error handling based on the sequence type that is returned from
+ * this function. If the user didn't declare a type, the type is <tt>item()*</tt>(zero or
+ * more items). Quaranteed to never be @c null.
+ * @returns the sequence type of the value this ExternalVariableLoader actually supplies. However,
+ * if the ExternalVariableLoader knows it cannot supply a variable by this name, @c null should be
+ * returned.
+ */
+ virtual SequenceType::Ptr announceExternalVariable(const QXmlName name,
+ const SequenceType::Ptr &declaredType);
+
+ /**
+ * This function is called at runtime when the external variable by name @p name needs
+ * to be evaluated. It is not defined how many times this function will be called. It
+ * depends on aspects such as how the query was optimized.
+ *
+ * @param name the name of the variable. Quaranteed to never be @c null.
+ * @param context the DynamicContext.
+ * @returns the value of the variable. Remember that this value must match the
+ * sequence type returned from announceExternalVariable() for the same name.
+ */
+ virtual Item::Iterator::Ptr evaluateSequence(const QXmlName name,
+ const QExplicitlySharedDataPointer<DynamicContext> &context);
+
+ virtual Item evaluateSingleton(const QXmlName name,
+ const QExplicitlySharedDataPointer<DynamicContext> &context);
+ virtual bool evaluateEBV(const QXmlName name,
+ const QExplicitlySharedDataPointer<DynamicContext> &context);
+ };
+}
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif