/************************************************************************
 * This file has been generated automatically from                      *
 *                                                                      *
 * src/core/qgsdefaultvalue.h                                           *
 *                                                                      *
 * Do not edit manually ! Edit header and run scripts/sipify.py again   *
 ************************************************************************/




class QgsDefaultValue
{
%Docstring(signature="appended")

The :py:class:`QgsDefaultValue` class provides a container for managing client
side default values for fields.

A :py:class:`QgsDefaultValue` consists of an expression string that will be evaluated
on the client when a default field value needs to be generated.

Usual values for such an expression are

- :py:func:`~now` for a timestamp for a record
- `@some_variable` to insert a project or application level variable like
  the username of the one digitizing a feature
- `$length` to insert a derived attribute of a geometry

:py:class:`QgsDefaultValue` also has a `applyOnUpdate` flag which will indicate that a
default value should also be applied when a feature is updated. If this is
not set, the default value will only be used when a feature is created.
%End

%TypeHeaderCode
#include "qgsdefaultvalue.h"
%End
  public:

    explicit QgsDefaultValue( const QString &expression = QString(), bool applyOnUpdate = false );
%Docstring
Create a new default value with the given ``expression`` and ``applyOnUpdate`` flag.

.. seealso:: :py:func:`QgsVectorLayer.setDefaultValueDefinition`
%End

    bool operator==( const QgsDefaultValue &other ) const;

    SIP_PYOBJECT __repr__();
%MethodCode
    const QString str = sipCpp->isValid() ? QStringLiteral( "<QgsDefaultValue: %1>" ).arg(
                          sipCpp->expression().length() > 1000 ? sipCpp->expression().left( 1000 ) + QStringLiteral( "..." )
                          : sipCpp->expression() )
                        : QStringLiteral( "<QgsDefaultValue: invalid>" );
    sipRes = PyUnicode_FromString( str.toUtf8().constData() );
%End

    QString expression() const;
%Docstring
The expression will be evaluated whenever a default value needs
to be calculated for a field.
%End

    void setExpression( const QString &expression );
%Docstring
The expression will be evaluated whenever a default value needs
to be calculated for a field.
%End

    bool applyOnUpdate() const;
%Docstring
The applyOnUpdate flag determines if this expression should also be
applied when a feature is updated or only when it's created.
%End

    void setApplyOnUpdate( bool applyOnUpdate );
%Docstring
The applyOnUpdate flag determines if this expression should also be
applied when a feature is updated or only when it's created.
%End

    bool isValid() const;
%Docstring
Returns if this default value should be applied.

:return: ``False`` if the expression is a null string.
%End


};


/************************************************************************
 * This file has been generated automatically from                      *
 *                                                                      *
 * src/core/qgsdefaultvalue.h                                           *
 *                                                                      *
 * Do not edit manually ! Edit header and run scripts/sipify.py again   *
 ************************************************************************/