reportdesign/source/core/misc/conditionalexpression.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19 #include "conditionalexpression.hxx"
  20
  21 //........................................................................
  22 namespace rptui
  23 {
  24     // =============================================================================
  25     // = ConditionalExpression
  26     // =============================================================================
  27     // -----------------------------------------------------------------------------
  28     ConditionalExpression::ConditionalExpression( const sal_Char* _pAsciiPattern )
  29         :m_sPattern( OUString::createFromAscii( _pAsciiPattern ) )
  30     {
  31     }
  32
  33     // -----------------------------------------------------------------------------
  34     OUString ConditionalExpression::assembleExpression( const OUString& _rFieldDataSource, const OUString& _rLHS, const OUString& _rRHS ) const
  35     {
  36         OUString sExpression( m_sPattern );
  37
  38         sal_Int32 nPatternIndex = sExpression.indexOf( '$' );
  39         while ( nPatternIndex > -1 )
  40         {
  41             const OUString* pReplace = NULL;
  42             switch ( sExpression.getStr()[ nPatternIndex + 1 ] )
  43             {
  44             case '$': pReplace = &_rFieldDataSource; break;
  45             case '1': pReplace = &_rLHS; break;
  46             case '2': pReplace = &_rRHS; break;
  47             default: break;
  48             }
  49
  50             if ( pReplace == NULL )
  51             {
  52                 OSL_FAIL( "ConditionalExpression::assembleExpression: illegal pattern!" );
  53                 break;
  54             }
  55
  56             sExpression = sExpression.replaceAt( nPatternIndex, 2, *pReplace );
  57             nPatternIndex = sExpression.indexOf( '$', nPatternIndex + pReplace->getLength() + 1 );
  58         }
  59         return sExpression;
  60     }
  61
  62     // -----------------------------------------------------------------------------
  63     bool ConditionalExpression::matchExpression( const OUString& _rExpression, const OUString& _rFieldDataSource, OUString& _out_rLHS, OUString& _out_rRHS ) const
  64     {
  65         (void)_rExpression;
  66         (void)_rFieldDataSource;
  67         (void)_out_rLHS;
  68         (void)_out_rRHS;
  69
  70         // if we had regular expression, the matching would be pretty easy ...
  71         // just replace $1 and $2 in the pattern with (.*), and then get them with \1 resp. \2.
  72         // Unfortunately, we don't have such a regexp engine ...
  73
  74         // Okay, let's start with replacing all $$ in our pattern with the actual field data source
  75         OUString sMatchExpression( m_sPattern );
  76         const OUString sFieldDataPattern( "$$" );
  77         sal_Int32 nIndex( sMatchExpression.indexOf( sFieldDataPattern ) );
  78         while ( nIndex != -1 )
  79         {
  80             sMatchExpression = sMatchExpression.replaceAt( nIndex, sFieldDataPattern.getLength(), _rFieldDataSource );
  81             nIndex = sMatchExpression.indexOf( sFieldDataPattern, nIndex + _rFieldDataSource.getLength() );
  82         }
  83
  84         const OUString sLHSPattern( "$1" );
  85         const OUString sRHSPattern( "$2" );
  86         sal_Int32 nLHSIndex( sMatchExpression.indexOf( sLHSPattern ) );
  87         sal_Int32 nRHSIndex( sMatchExpression.indexOf( sRHSPattern ) );
  88
  89         // now we should have at most one occurrence of $1 and $2, resp.
  90         OSL_ENSURE( sMatchExpression.indexOf( sLHSPattern, nLHSIndex + 1 ) == -1,
  91             "ConditionalExpression::matchExpression: unsupported pattern (more than one LHS occurrence)!" );
  92         OSL_ENSURE( sMatchExpression.indexOf( sRHSPattern, nRHSIndex + 1 ) == -1,
  93             "ConditionalExpression::matchExpression: unsupported pattern (more than one RHS occurrence)!" );
  94         // Also, an LHS must be present, and precede the RHS (if present)
  95         OSL_ENSURE( ( nLHSIndex != -1 ) && ( ( nLHSIndex < nRHSIndex ) || ( nRHSIndex == -1 ) ),
  96             "ConditionalExpression::matchExpression: no LHS, or an RHS preceeding the LHS - this is not supported!" );
  97
  98         // up to the occurrence of the LHS (which must exist, see above), the two expressions
  99         // must be identical
 100         if ( _rExpression.getLength() < nLHSIndex )
 101             return false;
 102         const OUString sExprPart1( _rExpression.copy( 0, nLHSIndex ) );
 103         const OUString sMatchExprPart1( sMatchExpression.copy( 0, nLHSIndex ) );
 104         if ( sExprPart1 != sMatchExprPart1 )
 105             // the left-most expression parts do not match
 106             return false;
 107
 108         // after the occurrence of the RHS (or the LHS, if there is no RHS), the two expressions
 109         // must be identical, too
 110         bool bHaveRHS( nRHSIndex != -1 );
 111         sal_Int32 nRightMostIndex( bHaveRHS ? nRHSIndex : nLHSIndex );
 112         const OUString sMatchExprPart3( sMatchExpression.copy( nRightMostIndex + 2 ) );
 113         if ( _rExpression.getLength() < sMatchExprPart3.getLength() )
 114             // the expression is not even long enough to hold the right-most part of the match expression
 115             return false;
 116         const OUString sExprPart3( _rExpression.copy( _rExpression.getLength() - sMatchExprPart3.getLength() ) );
 117         if ( sExprPart3 != sMatchExprPart3 )
 118             // the right-most expression parts do not match
 119             return false;
 120
 121         // if we don't have an RHS, we're done
 122         if ( !bHaveRHS )
 123         {
 124             _out_rLHS = _rExpression.copy( sExprPart1.getLength(), _rExpression.getLength() - sExprPart1.getLength() - sExprPart3.getLength() );
 125             return true;
 126         }
 127
 128         // strip the match expression by its right-most and left-most part, and by the placeholders $1 and $2
 129         sal_Int32 nMatchExprPart2Start( nLHSIndex + sLHSPattern.getLength() );
 130         OUString sMatchExprPart2 = sMatchExpression.copy(
 131             nMatchExprPart2Start,
 132             sMatchExpression.getLength() - nMatchExprPart2Start - sMatchExprPart3.getLength() - 2
 133         );
 134         // strip the expression by its left-most and right-most part
 135         const OUString sExpression( _rExpression.copy(
 136             sExprPart1.getLength(),
 137             _rExpression.getLength() - sExprPart1.getLength() - sExprPart3.getLength()
 138         ) );
 139
 140         sal_Int32 nPart2Index = sExpression.indexOf( sMatchExprPart2 );
 141         if ( nPart2Index == -1 )
 142             // the "middle" part of the match expression does not exist in the expression at all
 143             return false;
 144
 145         OSL_ENSURE( sExpression.indexOf( sMatchExprPart2, nPart2Index + 1 ) == -1,
 146             "ConditionalExpression::matchExpression: ambiguous matching!" );
 147             // if this fires, then we're lost: The middle part exists two times in the expression,
 148             // so we cannot reliably determine what's the LHS and what's the RHS.
 149             // Well, the whole mechanism is flawed, anyway:
 150             // Encoding the field content in the conditional expression will break as soon
 151             // as somebody
 152             // - assigns a Data Field to a control
 153             // - creates a conditional format expression for the control
 154             // - assigns another Data Field to the control
 155             // - opens the Conditional Format Dialog, again
 156             // Here, at the latest, you can see that we need another mechanism, anyway, which does not
 157             // rely on those strange expression building/matching
 158
 159         _out_rLHS = sExpression.copy( 0, nPart2Index );
 160         _out_rRHS = sExpression.copy( nPart2Index + sMatchExprPart2.getLength() );
 161
 162         return true;
 163     }
 164
 165     // =============================================================================
 166     // = ConditionalExpressionFactory
 167     // =============================================================================
 168     // -----------------------------------------------------------------------------
 169     size_t ConditionalExpressionFactory::getKnownConditionalExpressions( ConditionalExpressions& _out_rCondExp )
 170     {
 171         ConditionalExpressions aEmpty;
 172         _out_rCondExp.swap( aEmpty );
 173
 174         _out_rCondExp[ eBetween ]        = PConditionalExpression( new ConditionalExpression( "AND( ( $$ ) >= ( $1 ); ( $$ ) <= ( $2 ) )" ) );
 175         _out_rCondExp[ eNotBetween ]     = PConditionalExpression( new ConditionalExpression( "NOT( AND( ( $$ ) >= ( $1 ); ( $$ ) <= ( $2 ) ) )" ) );
 176         _out_rCondExp[ eEqualTo ]        = PConditionalExpression( new ConditionalExpression( "( $$ ) = ( $1 )" ) );
 177         _out_rCondExp[ eNotEqualTo ]     = PConditionalExpression( new ConditionalExpression( "( $$ ) <> ( $1 )" ) );
 178         _out_rCondExp[ eGreaterThan ]    = PConditionalExpression( new ConditionalExpression( "( $$ ) > ( $1 )" ) );
 179         _out_rCondExp[ eLessThan ]       = PConditionalExpression( new ConditionalExpression( "( $$ ) < ( $1 )" ) );
 180         _out_rCondExp[ eGreaterOrEqual ] = PConditionalExpression( new ConditionalExpression( "( $$ ) >= ( $1 )" ) );
 181         _out_rCondExp[ eLessOrEqual ]    = PConditionalExpression( new ConditionalExpression( "( $$ ) <= ( $1 )" ) );
 182
 183         return _out_rCondExp.size();
 184     }
 185 //........................................................................
 186 } // namespace rptui
 187 //........................................................................
 188
 189 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */