Export QgsOptional<QgsExpression> to dll/so

Author: m-kuhn

python/core/qgsoptionalexpression.sip

@@ -80,4 +80,21 @@ class QgsOptionalExpression
      * @note Added in QGIS 3.0
      */
     void setData( const QgsExpression& data );
+
+    /**
+     * Save the optional expression to the provided QDomElement.
+     *
+     * The caller is responsible to pass an empty QDomElement and to append it to
+     * a parent element.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void writeXml(QDomElement& parent );
+
+    /**
+     * Read the optional expression from the provided QDomElement.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void readXml(const QDomElement& parent );
 };

src/core/CMakeLists.txt

@@ -163,7 +163,7 @@ SET(QGIS_CORE_SRCS
   qgsofflineediting.cpp
   qgsogcutils.cpp
   qgsogrutils.cpp
-  qgsoptional.cpp
+  qgsoptionalexpression.cpp
   qgsowsconnection.cpp
   qgspaintenginehack.cpp
   qgspallabeling.cpp

src/core/qgsoptional.cpp

@@ -130,8 +130,8 @@ class CORE_EXPORT QgsOptional
     }
 
   private:
-    T mData;
     bool mEnabled;
+    T mData;
 };
 
 #endif // QGSOPTIONAL_H

src/core/qgsoptional.h

@@ -0,0 +1,48 @@
+/***************************************************************************
+  qgsoptionalexpression - QgsOptionalExpression
+
+ ---------------------
+ begin                : 14.9.2016
+ copyright            : (C) 2016 by Matthias Kuhn
+ email                : matthias@opengis.ch
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsoptionalexpression.h"
+
+QgsOptionalExpression::QgsOptionalExpression()
+    : QgsOptional<QgsExpression>()
+{
+
+}
+
+QgsOptionalExpression::QgsOptionalExpression( const QgsExpression& expression )
+    : QgsOptional<QgsExpression>( expression )
+{
+
+}
+
+QgsOptionalExpression::QgsOptionalExpression( const QgsExpression& expression, bool enabled )
+    : QgsOptional<QgsExpression>( expression, enabled )
+{
+
+}
+
+void QgsOptionalExpression::writeXml( QDomElement& element )
+{
+  QDomText exp = element.ownerDocument().createTextNode( data().expression() );
+  element.setAttribute( "enabled", enabled() );
+  element.appendChild( exp );
+}
+
+void QgsOptionalExpression::readXml( const QDomElement& element )
+{
+  setEnabled( element.attribute( "enabled" ).toInt() );
+  setData( element.text() );
+}

src/core/qgsoptionalexpression.cpp

@@ -28,6 +28,43 @@
  *
  * Added in QGIS 3.0
  */
-typedef QgsOptional<QgsExpression> QgsOptionalExpression;
+
+class CORE_EXPORT QgsOptionalExpression : public QgsOptional<QgsExpression>
+{
+  public:
+    /**
+     * Construct a default optional expression.
+     * It will be disabled and with an empty expression.
+     */
+    QgsOptionalExpression();
+
+    /**
+     * Construct an optional expression with the provided expression.
+     * It will be enabled.
+     */
+    QgsOptionalExpression( const QgsExpression& expression );
+
+    /**
+     * Construct an optional expression with the provided expression and enabled state.
+     */
+    QgsOptionalExpression( const QgsExpression& expression, bool enabled );
+
+    /**
+     * Save the optional expression to the provided QDomElement.
+     *
+     * The caller is responsible to pass an empty QDomElement and to append it to
+     * a parent element.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void writeXml( QDomElement& element );
+
+    /**
+     * Read the optional expression from the provided QDomElement.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void readXml( const QDomElement& element );
+};
 
 #endif // QGSOPTIONALEXPRESSION_H