QGIS API Documentation  2.18.21-Las Palmas (9fba24a)
qgsoptionalexpression.h
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1 /***************************************************************************
2  qgsoptionalexpression.h - QgsOptionalExpression
3 
4  ---------------------
5  begin : 8.9.2016
6  copyright : (C) 2016 by Matthias Kuhn
7  email : [email protected]
8  ***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 #ifndef QGSOPTIONALEXPRESSION_H
17 #define QGSOPTIONALEXPRESSION_H
18 
19 #include "qgsoptional.h"
20 #include "qgsexpression.h"
21 
34 class CORE_EXPORT QgsOptionalExpression : public QgsOptional<QgsExpression>
35 {
36  public:
42 
47  QgsOptionalExpression( const QgsExpression& expression );
48 
52  QgsOptionalExpression( const QgsExpression& expression, bool enabled );
53 
62  void writeXml( QDomElement& element );
63 
69  void readXml( const QDomElement& element );
70 };
71 
72 #if defined(Q_OS_WIN)
73 template CORE_EXPORT QgsOptional<QgsExpression>;
74 #endif
75 
76 #endif // QGSOPTIONALEXPRESSION_H
Class for parsing and evaluation of expressions (formerly called "search strings").
An expression with an additional enabled flag.
QgsOptional is a container for other classes and adds an additional enabled/disabled flag...
Definition: qgsoptional.h:32