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StringValue.h

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00001 #ifndef _STRINGVALUE_H_
00002 #define _STRINGVALUE_H_
00003 // 
00004 
00005 //
00006 // Copyright (C) 2004-2006  Autodesk, Inc.
00007 // 
00008 // This library is free software; you can redistribute it and/or
00009 // modify it under the terms of version 2.1 of the GNU Lesser
00010 // General Public License as published by the Free Software Foundation.
00011 // 
00012 // This library is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015 // Lesser General Public License for more details.
00016 // 
00017 // You should have received a copy of the GNU Lesser General Public
00018 // License along with this library; if not, write to the Free Software
00019 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00020 //
00021 
00022 #ifdef _WIN32
00023 #pragma once
00024 #endif
00025 
00026 #include <FdoStd.h>
00027 #include <Fdo/Expression/DataValue.h>
00028 #include <Fdo/Schema/DataType.h>
00029 
00030 /// \brief
00031 /// The FdoStringValue class derives from FdoDataValue and represents a literal string.
00032 class FdoStringValue : public FdoDataValue
00033 {
00034     friend class FdoBooleanValue;
00035     friend class FdoByteValue;
00036     friend class FdoDateTimeValue;
00037     friend class FdoDecimalValue;
00038     friend class FdoDoubleValue;
00039     friend class FdoInt16Value;
00040     friend class FdoInt32Value;
00041     friend class FdoInt64Value;
00042     friend class FdoSingleValue;
00043     friend class FdoDataValue;
00044 /// \cond DOXYGEN-IGNORE
00045 protected:
00046     /// \brief
00047     /// Constructs a default instance of an FdoStringValue with a
00048     /// value of null.
00049     /// \return
00050     /// Returns nothing
00051     /// 
00052     FdoStringValue();
00053 
00054     /// \brief
00055     /// Constructs a default instance of an FdoStringValue using the specified arguments.
00056     /// \return
00057     /// Returns nothing
00058     /// 
00059     FdoStringValue(FdoString* value);
00060 
00061     /// \brief
00062     /// Default destructor for FdoStringValue.
00063     virtual ~FdoStringValue();
00064 
00065     virtual void Dispose();
00066 /// \endcond
00067 
00068 public:
00069     /// \brief
00070     /// Constructs a default instance of an FdoStringValue with a value of null.
00071     /// 
00072     /// \return
00073     /// Returns the created FdoStringValue
00074     /// 
00075     FDO_API static FdoStringValue* Create();
00076 
00077     /// \brief
00078     /// Constructs a default instance of an FdoStringValue using the specified arguments.
00079     /// 
00080     /// \param value 
00081     /// Input a character string
00082     /// 
00083     /// \return
00084     /// Returns the created FdoStringValue
00085     /// 
00086     FDO_API static FdoStringValue* Create(FdoString* value);
00087 
00088     /// \brief
00089     /// Gets the data type of the FdoStringValue.
00090     /// 
00091     /// \return
00092     /// Returns FdoDataType
00093     /// 
00094     FDO_API FdoDataType GetDataType();
00095 
00096     /// \brief
00097     /// Gets the FdoStringValue as a string.
00098     /// 
00099     /// \return
00100     /// Returns a character string
00101     /// 
00102     FDO_API FdoString* GetString();
00103 
00104     /// \brief
00105     /// Sets the FdoStringValue as a string.
00106     /// 
00107     /// \param value 
00108     /// Input a character string
00109     /// 
00110     /// \return
00111     /// Returns nothing
00112     /// 
00113     FDO_API void SetString(FdoString* value);
00114 
00115     /// \brief
00116     /// Sets the FdoStringValue to a null value.
00117     /// 
00118     /// \return
00119     /// Returns nothing
00120     /// 
00121     FDO_API void SetNull();
00122 
00123     /// \brief
00124     /// Overrides FdoExpression.Process to pass the FdoStringValue to the appropriate
00125     /// expression processor operation.
00126     /// 
00127     /// \param p 
00128     /// Input an FdoIExpressionProcessor
00129     /// 
00130     /// \return
00131     /// Returns nothing
00132     /// 
00133     FDO_API void Process(FdoIExpressionProcessor* p);
00134 
00135     /// \brief
00136     /// Returns the well defined text representation of this expression.
00137     /// 
00138     /// \return
00139     /// Returns a character string
00140     /// 
00141     FDO_API FdoString* ToString();
00142 
00143     /// \brief
00144     /// A cast operator to get the string.
00145     /// 
00146     /// \return
00147     /// Returns a character string
00148     /// 
00149     FDO_API operator wchar_t*()
00150     {
00151         return m_data;
00152     }
00153 
00154 protected:
00155     /// \brief
00156     /// Constructs an instance of an FdoStringValue from another FdoDataValue.
00157     /// 
00158     /// \param src 
00159     /// Input the other FdoDataValue. Must be of one of the following types:
00160     ///     FdoDataType_Boolean
00161     ///     FdoDataType_Byte
00162     ///     FdoDataType_Decimal
00163     ///     FdoDataType_Double
00164     ///     FdoDataType_Int16
00165     ///     FdoDataType_Int32
00166     ///     FdoDataType_Int64
00167     ///     FdoDataType_Single
00168     ///     FdoDataType_String
00169     ///
00170     /// In all other cases, the src type is considered incompatible with this type.
00171     /// \param nullIfIncompatible 
00172     /// Input will determine what to do if the source value cannot be converted to 
00173     /// this type:
00174     ///     true - return NULL.
00175     ///     false - throw an exception
00176     /// 
00177     /// \param shift 
00178     /// Input determines whether FdoFloat or FdoDouble values are allowed to shift 
00179     /// when conversion to strings causes loss of precision.
00180     ///     true - convert values allowing them to shift.
00181     ///     false - behaviour depends on nullIfIncompatible:
00182     ///         true - return NULL.
00183     ///         false - throw an exception
00184     /// \param truncate 
00185     /// Input for future use. There are currently no possible out of range
00186     /// src values.
00187     /// \return
00188     /// Returns an FdoStringValue, whose value is converted from the src value. 
00189     /// If src is an FdoStringValue then its value is simply copied to the 
00190     /// returned FdoStringValue. Otherwise, the value is converted by calling
00191     /// src->ToString().
00192     ///
00193     static FdoStringValue* Create(
00194         FdoDataValue* src, 
00195         FdoBoolean nullIfIncompatible = false,
00196         FdoBoolean shift = true, 
00197         FdoBoolean truncate = false 
00198     );
00199 
00200     template <class C> C* ConvertFrom( bool nullIfIncompatible, bool shift, bool truncate, FdoString* sTO )
00201     {
00202         C*   ret = NULL;
00203         FdoPtr<FdoDataValue> parsed = Parse();
00204         
00205         if ( (parsed == NULL) || (parsed->IsNull()) || (parsed->GetDataType() == FdoDataType_String) ) 
00206         {
00207             if ( !nullIfIncompatible )
00208                 throw FdoExpressionException::Create(
00209                     FdoException::NLSGetMessage(
00210                         FDO_NLSID(EXPRESSION_22_INCOMPATIBLEDATATYPES),
00211                         this->ToString(),
00212                         (FdoString *) DataTypeToString(GetDataType()),
00213                         sTO
00214                     )
00215                 );
00216         }
00217         else
00218         {
00219             ret = C::Create(parsed, nullIfIncompatible, shift, truncate);
00220         };
00221 
00222         return ret;
00223     };
00224 
00225     // See FdoDataValue::DoCompare()
00226     virtual FdoCompareType DoCompare( FdoDataValue* other );
00227 
00228     FdoDataValue* Parse();
00229 
00230     wchar_t*    m_data;
00231     size_t      m_allocatedSize;
00232 };
00233 #endif
00234 
00235 
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