QGIS API Documentation  3.8.0-Zanzibar (11aff65)
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 : matthias@opengis.ch
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 
22 #include "qgis_core.h"
23 
24 
39 class CORE_EXPORT QgsOptionalExpression : public QgsOptional<QgsExpression>
40 {
41  public:
42 
47  QgsOptionalExpression() = default;
48 
53  QgsOptionalExpression( const QgsExpression &expression );
54 
58  QgsOptionalExpression( const QgsExpression &expression, bool enabled );
59 
60 
69  void writeXml( QDomElement &element );
70 
76  void readXml( const QDomElement &element );
77 };
78 
79 
80 #if defined(_MSC_VER)
81 #ifndef SIP_RUN
82 template CORE_EXPORT QgsOptional<QgsExpression>;
83 #endif
84 #endif
85 
86 
87 #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:36