qgsvectorlayerjoininfo.cpp

Go to the documentation of this file.

/***************************************************************************
                          qgsvectorlayerjoininfo.cpp
                          --------------------------
    begin                : Jun 29, 2017
    copyright            : (C) 2017 by Paul Blottiere
    email                : [email protected]
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   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 "qgsvectorlayerjoininfo.h"
#include "qgsvectorlayer.h"
 
QString QgsVectorLayerJoinInfo::prefixedFieldName( const QgsField &f ) const
{
  QString name;
 
  if ( auto *lJoinLayer = joinLayer() )
  {
    if ( prefix().isNull() )
      name = lJoinLayer->name() + '_';
    else
      name = prefix();
 
    name += f.name();
  }
 
  return name;
}
 
void QgsVectorLayerJoinInfo::setUsingMemoryCache( bool enabled )
{
  mMemoryCache = enabled;
}
 
bool QgsVectorLayerJoinInfo::isUsingMemoryCache() const
{
  if ( mUpsertOnEdit )
    return false;
 
  return mMemoryCache;
}
 
void QgsVectorLayerJoinInfo::setEditable( bool enabled )
{
  mEditable = enabled;
 
  if ( ! mEditable )
  {
    setCascadedDelete( false );
    setUpsertOnEdit( false );
  }
}
 
QgsFeature QgsVectorLayerJoinInfo::extractJoinedFeature( const QgsFeature &feature ) const
{
  QgsFeature joinFeature;
 
  if ( auto *lJoinLayer = joinLayer() )
  {
    const QVariant idFieldValue = feature.attribute( targetFieldName() );
    joinFeature.initAttributes( lJoinLayer->fields().count() );
    joinFeature.setFields( lJoinLayer->fields() );
    joinFeature.setAttribute( joinFieldName(), idFieldValue );
 
    const QgsFields joinFields = joinFeature.fields();
    for ( const auto &field : joinFields )
    {
      const QString prefixedName = prefixedFieldName( field );
 
      if ( feature.fieldNameIndex( prefixedName ) != -1 )
        joinFeature.setAttribute( field.name(), feature.attribute( prefixedName ) );
    }
  }
 
  return joinFeature;
}
 
QStringList QgsVectorLayerJoinInfo::joinFieldNamesSubset( const QgsVectorLayerJoinInfo &info, bool blocklisted )
{
  QStringList fieldNames;
 
  if ( blocklisted && !info.joinFieldNamesBlockList().isEmpty() )
  {
    QStringList *lst = info.joinFieldNamesSubset();
    if ( lst )
    {
      for ( const QString &s : qgis::as_const( *lst ) )
      {
        if ( !info.joinFieldNamesBlockList().contains( s ) )
          fieldNames.append( s );
      }
    }
    else
    {
      if ( auto *lJoinLayer = info.joinLayer() )
      {
        const QgsFields fields { lJoinLayer->fields() };
        for ( const QgsField &f : fields )
        {
          if ( !info.joinFieldNamesBlockList().contains( f.name() )
               && f.name() != info.joinFieldName() )
            fieldNames.append( f.name() );
        }
      }
    }
  }
  else
  {
    QStringList *lst = info.joinFieldNamesSubset();
    if ( lst )
    {
      fieldNames = *lst;
    }
  }
 
  return fieldNames;
}
 
bool QgsVectorLayerJoinInfo::hasSubset( bool blocklisted ) const
{
  bool subset = joinFieldNamesSubset();
 
  if ( blocklisted )
    subset |= !joinFieldNamesBlockList().isEmpty();
 
  return subset;
}