ossimFgdcTxtDoc Class Reference

Support data container for FGDC in text format. More...

#include <ossimFgdcTxtDoc.h>

Inheritance diagram for ossimFgdcTxtDoc:

Public Member Functions
	ossimFgdcTxtDoc ()
	default constructor More...
virtual	~ossimFgdcTxtDoc ()
	virtual destructor More...
bool	open (const ossimFilename &file)
	open method. More...
void	close ()
	Close method. More...
void	getProjection (ossimRefPtr< ossimProjection > &proj)
	Gets projection from Spatial_Reference_Information block. More...
void	getAltitudeDistanceUnits (std::string &units) const
	Gets units from Altitude_Distance_Units. More...
Public Member Functions inherited from ossimReferenced
	ossimReferenced ()
	ossimReferenced (const ossimReferenced &)
ossimReferenced &	operator= (const ossimReferenced &)
void	ref () const
	increment the reference count by one, indicating that this object has another pointer which is referencing it. More...
void	unref () const
	decrement the reference count by one, indicating that a pointer to this object is referencing it. More...
void	unref_nodelete () const
	decrement the reference count by one, indicating that a pointer to this object is referencing it. More...
int	referenceCount () const

Private Member Functions
void	getProjectionV1 (std::ifstream &str, ossimRefPtr< ossimProjection > &proj)
	Gets projection from Spatial_Reference_Information block for version FGDC-STD-001-1998. More...
bool	findKey (std::ifstream &str, const std::string &key)
	Finds key and returns true if present. More...
bool	findKey (std::ifstream &str, bool seekBack, const std::string &key, std::string &value)
	Finds key and returns and intializes value if present. More...
void	getOssimDatum (const std::string &fgdcDatumString, std::string &ossimDatumCode) const
	Gets ossim datum string from fgdc datum string. More...

Private Attributes
ossimRefPtr< ossimKeywordlist >	m_kwl

Additional Inherited Members
Protected Member Functions inherited from ossimReferenced
virtual	~ossimReferenced ()

Detailed Description

Support data container for FGDC in text format.

Has minimum parse support to get Spatial_Reference_Information section to extract projection information.

TODO: Make an ossimFgdcBase and consolidate code from ossimFgdcXmlDoc and this class. (drb - 15 Aug. 2011)

Definition at line 38 of file ossimFgdcTxtDoc.h.

Constructor & Destructor Documentation

ossimFgdcTxtDoc()

ossimFgdcTxtDoc::ossimFgdcTxtDoc

(

)

default constructor

Definition at line 35 of file ossimFgdcTxtDoc.cpp.

   : m_kwl( new ossimKeywordlist() )
{
}

~ossimFgdcTxtDoc()

ossimFgdcTxtDoc::~ossimFgdcTxtDoc ( )

virtual

virtual destructor

Definition at line 40 of file ossimFgdcTxtDoc.cpp.

References m_kwl.

{
   m_kwl = 0; // Not a leak, m_kwl is a ossimRefPtr.
}

Member Function Documentation

close()

void ossimFgdcTxtDoc::close

(

)

Close method.

This doesn't really do anything. Here only because I think every open() should have a matching close().

Definition at line 77 of file ossimFgdcTxtDoc.cpp.

References ossimKeywordlist::clear(), and m_kwl.

{
   m_kwl->clear();
}

findKey() [1/2]

bool ossimFgdcTxtDoc::findKey ( std::ifstream &  str, const std::string &  key  )

private

Finds key and returns true if present.

Leaves stream at position of last getline.

Parameters

str	Stream to read from.
key	Key to find.

Returns

true if present false if not.

Definition at line 208 of file ossimFgdcTxtDoc.cpp.

References getline(), ossimString::size(), ossimString::string(), and ossimString::trim().

Referenced by getProjectionV1(), and open().

{
   bool result = false;
   ossimString line;
   while ( !str.eof() )
   {
      // Read line:
      std::getline( str, line.string() );
      if ( line.size() )
      {
         // Eat white space.
         line.trim();
         if ( line.string() == key )
         {
            result = true;
            break;
         }
      }
   }
   return result;
}

findKey() [2/2]

bool ossimFgdcTxtDoc::findKey ( std::ifstream &  str, bool  seekBack, const std::string &  key, std::string &  value  )

private

Finds key and returns and intializes value if present.

Stream position at end of call is dependent on seekBack flag.

Parameters

str	Stream to read from.
seekBack	If true the stream will be repositioned to original position at beginning of the call.
key	Key to find.
value	Intialized with value if key is found.

Returns

true if present false if not.

Definition at line 230 of file ossimFgdcTxtDoc.cpp.

References ossimString::clear(), getline(), ossimString::size(), size, ossimString::split(), ossimString::string(), and ossimString::trim().

{
   bool result = false;

   std::vector<ossimString> fgdcKeyValue;
   ossimString separator = ":";
   ossimString line;
   ossimKeywordlist projectionKwl;
   std::streampos currentPosition = str.tellg();
   
   while ( !str.eof() )
   {
      // Read line:
      std::getline( str, line.string() );
      
      if ( line.size() )
      {
         // Eat white space.
         line.trim();
         
         // Split between ':'
         fgdcKeyValue.clear();
         line.split(fgdcKeyValue, separator, false);
         if ( fgdcKeyValue.size() == 2 )
         {
            fgdcKeyValue[0].trim();

            if ( fgdcKeyValue[0].size() )
            {
               if ( fgdcKeyValue[0] == key )
               {
                  // Found it.  Initialize value and get out.
                  result = true;
                  fgdcKeyValue[1].trim();
                  value = fgdcKeyValue[1].string();
                  break; // from while loop.
               }
            }
         }
      }
   }

   if ( seekBack )
   {
      str.seekg(currentPosition);
   }
   
   return result;
}

getAltitudeDistanceUnits()

void ossimFgdcTxtDoc::getAltitudeDistanceUnits

(

std::string &

units

)

const

Gets units from Altitude_Distance_Units.

Returns

Units if found, OSSIM_UNIT_UNKNOWN if not.

Definition at line 120 of file ossimFgdcTxtDoc.cpp.

References ossimKeywordlist::findKey(), and m_kwl.

{
   units = m_kwl->findKey( ALTITUDE_DISTANCE_UNITS_KW );
}

getOssimDatum()

void ossimFgdcTxtDoc::getOssimDatum ( const std::string &  fgdcDatumString, std::string &  ossimDatumCode  ) const

private

Gets ossim datum string from fgdc datum string.

Definition at line 282 of file ossimFgdcTxtDoc.cpp.

References ossimString::downcase(), and ossimString::string().

Referenced by getProjectionV1().

{
   ossimString horizdn = fgdcDatumString;
   horizdn.downcase();
   if ( horizdn == "north american datum of 1983" )
   {
      ossimDatumCode = "NAR-C";
   }
   else if ( horizdn == "north american datum of 1927" )
   {
      ossimDatumCode = "NAS-C";
   }
   else if ( horizdn == "wgs84")
   {
      ossimDatumCode = "WGE";
   }
   else
   {
      // Exception thrown so that we see that we are not handling a datum.
      std::string errMsg = "ossimFgdcTxtDoc::getOssimDatum ERROR: Unhandled datum: ";
      errMsg += horizdn.string();
      throw ossimException(errMsg);
   }
}

getProjection()

void ossimFgdcTxtDoc::getProjection

(

ossimRefPtr< ossimProjection > &

proj

)

Gets projection from Spatial_Reference_Information block.

Parameters

proj	Intialized by this method. Set to null on projection cannot be created.

Definition at line 82 of file ossimFgdcTxtDoc.cpp.

References ossimKeywordlist::findKey(), and m_kwl.

{
   static const char M[] = "ossimFgdcTxtDoc::getProjection";
   
   try
   {
      // Get the file name:
      std::string file = m_kwl->findKey( FGDC_FILE_KW );
      if ( file.size() )
      {
         // Get the version:
         std::string version = m_kwl->findKey( FGDC_VERSION_KW );
         if ( version.size() )
         {
            // Note: Currently only coded against FGDC-STD-001-1998
            if ( version ==  FGDC_VERSION_001_1998)
            {
               // Open the file:
               std::ifstream str( file.c_str(), std::ios_base::in );
               if ( str.good() )
               {
                  // Find the Spatial_Reference_Information  section:
                  std::string key = "Spatial_Reference_Information:";
                  if ( findKey( str, key ) )
                  {
                     getProjectionV1( str, proj );
                  }
               }
            }
         }
      }
   }
   catch (const ossimException& e)
   {
      ossimNotify(ossimNotifyLevel_WARN) << M << " caught exception:\n" << e.what() << std::endl;
   }
}

getProjectionV1()

void ossimFgdcTxtDoc::getProjectionV1 ( std::ifstream &  str, ossimRefPtr< ossimProjection > &  proj  )

private

Gets projection from Spatial_Reference_Information block for version FGDC-STD-001-1998.

Parameters

str	Stream to read from.
proj	Intialized by this method. Set to null on projection cannot be created.

Definition at line 125 of file ossimFgdcTxtDoc.cpp.

References ossimKeywordlist::addPair(), ossimMapProjectionFactory::createProjection(), findKey(), getOssimDatum(), ossimKeywordlist::getSize(), ossimMapProjectionFactory::instance(), and ossimString::toFloat64().

{
   static const char M[] = "ossimFgdcTxtDoc::getProjectionV1";
   
   std::string fgdcKey;
   std::string fgdcValue;
   std::string key;
   std::string value;
   ossimKeywordlist projectionKwl;
   
   fgdcKey = "Grid_Coordinate_System_Name";
   if ( findKey( str, true, fgdcKey, fgdcValue ) )
   {
      if ( fgdcValue == "Universal Transverse Mercator" )
      {
         key = "type";
         value = "ossimUtmProjection";
         projectionKwl.addPair(key, value);

         // Get the zone:
         fgdcKey = "UTM_Zone_Number";
         if ( findKey( str, true, fgdcKey, fgdcValue ) )
         {
            key = "zone";
            value = fgdcValue;
            projectionKwl.addPair(key, value);
         }
         else
         {
            std::string errMsg = M;
            errMsg += " ERROR: Could not determine utm zone!";
            throw ossimException(errMsg);
         }

         // Check for Southern hemisphere.
         fgdcKey = "False_Northing";
         if ( findKey( str, true, fgdcKey, fgdcValue ) )
         {
            key = "hemisphere";
            
            // Hemisphere( North false easting = 0.0, South = 10000000):
            ossim_float64 f = ossimString::toFloat64( fgdcKey.c_str() );
            if ( f == 0.0 )
            {
               value = "N";
            }
            else
            {
               value = "S";
            }
            projectionKwl.addPair(key, value);
         }
         
      } // UTM section:
      else
      {
         // Exception thrown so that we see that we are not handling a projection.
         std::string errMsg = M;
         errMsg += "ERROR: Unhandled projection: ";
         errMsg += fgdcValue;
         throw ossimException(errMsg);  
      }

      fgdcKey = "Horizontal_Datum_Name";
      if ( findKey( str, true, fgdcKey, fgdcValue ) )
      {
         getOssimDatum( fgdcValue, value );
         key = "datum";
         projectionKwl.addPair(key, value);
      }
      
   } // Matches: findKey( Grid_Coordinate_System_Name )

   if ( projectionKwl.getSize() )
   {
      proj = ossimMapProjectionFactory::instance()->createProjection(projectionKwl);
   }
   else
   {
      proj = 0;
   }
}

open()

bool ossimFgdcTxtDoc::open

(

const ossimFilename &

file

)

open method.

Parameters

file	File name to open.

Returns

true on success false on error.

Definition at line 45 of file ossimFgdcTxtDoc.cpp.

References ossimString::c_str(), and findKey().

{
   bool result = false;

   // Open the file:
   std::ifstream str( file.c_str(), std::ios_base::in );

   if ( str.good() )
   {
      std::string key = "Metadata_Standard_Version";
      std::string value;
      if ( findKey( str, true, key, value ) )
      {
         if ( value == FGDC_VERSION_001_1998 )
         {
            result = true;
            m_kwl->addPair( FGDC_VERSION_KW, value );
            m_kwl->addPair( FGDC_FILE_KW, file.string() );

            // Store for getAltitudeDistanceUnits() method if key found.
            key = "Altitude_Distance_Units";
            if ( findKey( str, false, key, value ) )
            {
               m_kwl->addPair( ALTITUDE_DISTANCE_UNITS_KW, value );
            }
         }
      }
   }

   return result;
}

Member Data Documentation

m_kwl

ossimRefPtr<ossimKeywordlist> ossimFgdcTxtDoc::m_kwl

private

Definition at line 125 of file ossimFgdcTxtDoc.h.

Referenced by close(), getAltitudeDistanceUnits(), getProjection(), and ~ossimFgdcTxtDoc().

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The documentation for this class was generated from the following files:

• ossimFgdcTxtDoc.h
• ossimFgdcTxtDoc.cpp