QGIS API Documentation  3.14.0-Pi (9f7028fd23)
qgsexpressioncontext.h File Reference
#include "qgis_core.h"
#include "qgis_sip.h"
#include <QVariant>
#include <QHash>
#include <QString>
#include <QStringList>
#include <QSet>
#include "qgsexpressionfunction.h"
#include "qgsfeature.h"
Include dependency graph for qgsexpressioncontext.h:

Go to the source code of this file.


class  QgsExpressionContext
 Expression contexts are used to encapsulate the parameters around which a QgsExpression should be evaluated. QgsExpressions can then utilize the information stored within a context to contextualise their evaluated result. A QgsExpressionContext consists of a stack of QgsExpressionContextScope objects, where scopes added later to the stack will override conflicting variables and functions from scopes lower in the stack. More...
class  QgsExpressionContextScope
 Single scope for storing variables and functions for use within a QgsExpressionContext. Examples include a project's scope, which could contain information about the current project such as the project file's location. QgsExpressionContextScope can encapsulate both variables (static values) and functions(which are calculated only when an expression is evaluated). More...
class  QgsScopedExpressionFunction
 Expression function for use within a QgsExpressionContextScope. This differs from a standard QgsExpression::Function in that it requires an implemented clone() method. More...
struct  QgsExpressionContextScope::StaticVariable
 Single variable definition for use within a QgsExpressionContextScope. More...