qgssqlexpressioncompiler.h

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/***************************************************************************
                             qgssqlexpressioncompiler.h
                             --------------------------
    begin                : November 2015
    copyright            : (C) 2015 Nyall Dawson
    email                : nyall dot dawson at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSSQLEXPRESSIONCOMPILER_H
#define QGSSQLEXPRESSIONCOMPILER_H

#include "qgsexpression.h"
#include "qgsfield.h"

class CORE_EXPORT QgsSqlExpressionCompiler
{
  public:

    enum Result
    {
      None, 
      Complete, 
      Partial, 
      Fail 
    };

    enum Flag
    {
      CaseInsensitiveStringMatch = 0x01,  
      LikeIsCaseInsensitive = 0x02, 
      NoNullInBooleanLogic = 0x04, 
      NoUnaryMinus = 0x08, 
    };
    Q_DECLARE_FLAGS( Flags, Flag )

    
    explicit QgsSqlExpressionCompiler( const QgsFields& fields, const Flags& flags = Flags() );
    virtual ~QgsSqlExpressionCompiler();

    virtual Result compile( const QgsExpression* exp );

    virtual QString result() { return mResult; }

  protected:

    virtual QString quotedIdentifier( const QString& identifier );

    virtual QString quotedValue( const QVariant& value, bool &ok );

    virtual Result compileNode( const QgsExpression::Node* node, QString& str );

    QString mResult;
    QgsFields mFields;

  private:

    Flags mFlags;

    bool nodeIsNullLiteral( const QgsExpression::Node* node ) const;

};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsSqlExpressionCompiler::Flags )

#endif // QGSSQLEXPRESSIONCOMPILER_H