Definition of a feature class or feature layer. More...

#include <ogr_feature.h>

Public Member Functions
	OGRFeatureDefn (const char *pszName=nullptr)
	Constructor. More...

void	SetName (const char *pszName)
	Change name of this OGRFeatureDefn. More...

virtual const char *	GetName () const
	Get name of this OGRFeatureDefn. More...

virtual int	GetFieldCount () const
	Fetch number of fields on this feature. More...

virtual OGRFieldDefn *	GetFieldDefn (int i)
	Fetch field definition. More...

virtual const OGRFieldDefn *	GetFieldDefn (int i) const
	Fetch field definition. More...

virtual int	GetFieldIndex (const char *) const
	Find field by name. More...

int	GetFieldIndexCaseSensitive (const char *) const
	Find field by name, in a case sensitive way. More...

virtual void	AddFieldDefn (OGRFieldDefn *)
	Add a new field definition. More...

virtual OGRErr	DeleteFieldDefn (int iField)
	Delete an existing field definition. More...

virtual OGRErr	ReorderFieldDefns (int *panMap)
	Reorder the field definitions in the array of the feature definition. More...

virtual int	GetGeomFieldCount () const
	Fetch number of geometry fields on this feature. More...

virtual OGRGeomFieldDefn *	GetGeomFieldDefn (int i)
	Fetch geometry field definition. More...

virtual const OGRGeomFieldDefn *	GetGeomFieldDefn (int i) const
	Fetch geometry field definition. More...

virtual int	GetGeomFieldIndex (const char *) const
	Find geometry field by name. More...

virtual void	AddGeomFieldDefn (OGRGeomFieldDefn *, int bCopy=TRUE)
	Add a new geometry field definition. More...

virtual OGRErr	DeleteGeomFieldDefn (int iGeomField)
	Delete an existing geometry field definition. More...

virtual OGRwkbGeometryType	GetGeomType () const
	Fetch the geometry base type. More...

virtual void	SetGeomType (OGRwkbGeometryType)
	Assign the base geometry type for this layer. More...

virtual OGRFeatureDefn *	Clone () const
	Create a copy of this feature definition. More...

int	Reference ()
	Increments the reference count by one. More...

int	Dereference ()
	Decrements the reference count by one. More...

int	GetReferenceCount () const
	Fetch current reference count. More...

void	Release ()
	Drop a reference to this object, and destroy if no longer referenced.

virtual int	IsGeometryIgnored () const
	Determine whether the geometry can be omitted when fetching features. More...

virtual void	SetGeometryIgnored (int bIgnore)
	Set whether the geometry can be omitted when fetching features. More...

virtual int	IsStyleIgnored () const
	Determine whether the style can be omitted when fetching features. More...

virtual void	SetStyleIgnored (int bIgnore)
	Set whether the style can be omitted when fetching features. More...

virtual int	IsSame (const OGRFeatureDefn *poOtherFeatureDefn) const
	Test if the feature definition is identical to the other one. More...

std::vector< int >	ComputeMapForSetFrom (const OGRFeatureDefn *poSrcFDefn, bool bForgiving=true) const
	Compute the map from source to target field that can be passed to SetFrom(). More...

Static Public Member Functions
static OGRFeatureDefn *	CreateFeatureDefn (const char *pszName=nullptr)
	Create a new feature definition object. More...

static void	DestroyFeatureDefn (OGRFeatureDefn *)
	Destroy a feature definition. More...

static OGRFeatureDefnH	ToHandle (OGRFeatureDefn *poFeatureDefn)
	Convert a OGRFeatureDefn* to a OGRFeatureDefnH. More...

static OGRFeatureDefn *	FromHandle (OGRFeatureDefnH hFeatureDefn)
	Convert a OGRFeatureDefnH to a OGRFeatureDefn*. More...

Detailed Description

Definition of a feature class or feature layer.

This object contains schema information for a set of OGRFeatures. In table based systems, an OGRFeatureDefn is essentially a layer. In more object oriented approaches (such as SF CORBA) this can represent a class of features but doesn't necessarily relate to all of a layer, or just one layer.

This object also can contain some other information such as a name and potentially other metadata.

It is essentially a collection of field descriptions (OGRFieldDefn class). Starting with GDAL 1.11, in addition to attribute fields, it can also contain multiple geometry fields (OGRGeomFieldDefn class).

It is reasonable for different translators to derive classes from OGRFeatureDefn with additional translator specific information.

Constructor & Destructor Documentation

◆ OGRFeatureDefn()

OGRFeatureDefn::OGRFeatureDefn ( const char * pszName = nullptr )

explicit

Constructor.

The OGRFeatureDefn maintains a reference count, but this starts at zero. It is mainly intended to represent a count of OGRFeature's based on this definition.

This method is the same as the C function OGR_FD_Create().

Parameters

pszName the name to be assigned to this layer/class. It does not need to be unique.

Member Function Documentation

◆ AddFieldDefn()

void OGRFeatureDefn::AddFieldDefn ( OGRFieldDefn * poNewDefn )

virtual

Add a new field definition.

To add a new field definition to a layer definition, do not use this function directly, but use OGRLayer::CreateField() instead.

This method should only be called while there are no OGRFeature objects in existence based on this OGRFeatureDefn. The OGRFieldDefn passed in is copied, and remains the responsibility of the caller.

This method is the same as the C function OGR_FD_AddFieldDefn().

Parameters

poNewDefn the definition of the new field.

◆ AddGeomFieldDefn()

void OGRFeatureDefn::AddGeomFieldDefn	(	OGRGeomFieldDefn *	poNewDefn,
		int	bCopy = `TRUE`
	)

virtual

Add a new geometry field definition.

To add a new geometry field definition to a layer definition, do not use this function directly, but use OGRLayer::CreateGeomField() instead.

This method does an internal copy of the passed geometry field definition, unless bCopy is set to FALSE (in which case it takes ownership of the field definition.

This method should only be called while there are no OGRFeature objects in existence based on this OGRFeatureDefn. The OGRGeomFieldDefn passed in is copied, and remains the responsibility of the caller.

This method is the same as the C function OGR_FD_AddGeomFieldDefn().

Parameters

poNewDefn	the definition of the new geometry field.
bCopy	whether poNewDefn should be copied.

Since: GDAL 1.11

◆ Clone()

OGRFeatureDefn * OGRFeatureDefn::Clone ( ) const

virtual

Create a copy of this feature definition.

Creates a deep copy of the feature definition.

Returns: the copy.

◆ ComputeMapForSetFrom()

std::vector< int > OGRFeatureDefn::ComputeMapForSetFrom	(	const OGRFeatureDefn *	poSrcFDefn,
		bool	bForgiving = `true`
	)		const

Compute the map from source to target field that can be passed to SetFrom().

Parameters

poSrcFDefn	the feature definition of source features later passed to SetFrom()
bForgiving	true if the operation should continue despite lacking output fields matching some of the source fields.

Returns: an array of size poSrcFDefn->GetFieldCount() if everything succeeds, or empty in case a source field definition was not found in the target layer and bForgiving == true.

Since: GDAL 2.3

◆ CreateFeatureDefn()

OGRFeatureDefn * OGRFeatureDefn::CreateFeatureDefn ( const char * pszName = nullptr )

static

Create a new feature definition object.

Parameters

pszName name

Returns: new feature definition object.

◆ DeleteFieldDefn()

OGRErr OGRFeatureDefn::DeleteFieldDefn ( int iField )

virtual

Delete an existing field definition.

To delete an existing field definition from a layer definition, do not use this function directly, but use OGRLayer::DeleteField() instead.

This method should only be called while there are no OGRFeature objects in existence based on this OGRFeatureDefn.

This method is the same as the C function OGR_FD_DeleteFieldDefn().

Parameters

iField the index of the field definition.

Returns: OGRERR_NONE in case of success.

Since: OGR 1.9.0

◆ DeleteGeomFieldDefn()

OGRErr OGRFeatureDefn::DeleteGeomFieldDefn ( int iGeomField )

virtual

Delete an existing geometry field definition.

To delete an existing field definition from a layer definition, do not use this function directly, but use OGRLayer::DeleteGeomField() instead.

This method should only be called while there are no OGRFeature objects in existence based on this OGRFeatureDefn.

This method is the same as the C function OGR_FD_DeleteGeomFieldDefn().

Parameters

iGeomField the index of the geometry field definition.

Returns: OGRERR_NONE in case of success.

Since: GDAL 1.11

◆ Dereference()

int OGRFeatureDefn::Dereference ( )

inline

Decrements the reference count by one.

This method is the same as the C function OGR_FD_Dereference().

Returns: the updated reference count.

◆ DestroyFeatureDefn()

void OGRFeatureDefn::DestroyFeatureDefn ( OGRFeatureDefn * poDefn )

static

Destroy a feature definition.

Parameters

poDefn feature definition.

◆ FromHandle()

static OGRFeatureDefn* OGRFeatureDefn::FromHandle ( OGRFeatureDefnH hFeatureDefn )

inlinestatic

Convert a OGRFeatureDefnH to a OGRFeatureDefn*.

Since: GDAL 2.3

◆ GetFieldCount()

int OGRFeatureDefn::GetFieldCount ( ) const

virtual

Fetch number of fields on this feature.

This method is the same as the C function OGR_FD_GetFieldCount().

Returns: count of fields.

◆ GetFieldDefn() [1/2]

OGRFieldDefn * OGRFeatureDefn::GetFieldDefn ( int iField )

virtual

Fetch field definition.

This method is the same as the C function OGR_FD_GetFieldDefn().

Parameters

iField the field to fetch, between 0 and GetFieldCount() - 1.

Returns: a pointer to an internal field definition object or NULL if invalid index. This object should not be modified or freed by the application.

◆ GetFieldDefn() [2/2]

const OGRFieldDefn * OGRFeatureDefn::GetFieldDefn ( int iField ) const

virtual

Fetch field definition.

This method is the same as the C function OGR_FD_GetFieldDefn().

Parameters

iField the field to fetch, between 0 and GetFieldCount() - 1.

Returns: a pointer to an internal field definition object or NULL if invalid index. This object should not be modified or freed by the application.

Since: GDAL 2.3

◆ GetFieldIndex()

int OGRFeatureDefn::GetFieldIndex ( const char * pszFieldName ) const

virtual

Find field by name.

The field index of the first field matching the passed field name (case insensitively) is returned.

This method is the same as the C function OGR_FD_GetFieldIndex().

Parameters

pszFieldName the field name to search for.

Returns: the field index, or -1 if no match found.

◆ GetFieldIndexCaseSensitive()

int OGRFeatureDefn::GetFieldIndexCaseSensitive ( const char * pszFieldName ) const

Find field by name, in a case sensitive way.

The field index of the first field matching the passed field name is returned.

Parameters

pszFieldName the field name to search for.

Returns: the field index, or -1 if no match found.

◆ GetGeomFieldCount()

int OGRFeatureDefn::GetGeomFieldCount ( ) const

virtual

Fetch number of geometry fields on this feature.

This method is the same as the C function OGR_FD_GetGeomFieldCount().

Returns: count of geometry fields.

Since: GDAL 1.11

◆ GetGeomFieldDefn() [1/2]

OGRGeomFieldDefn * OGRFeatureDefn::GetGeomFieldDefn ( int iGeomField )

virtual

Fetch geometry field definition.

This method is the same as the C function OGR_FD_GetGeomFieldDefn().

Parameters

iGeomField the geometry field to fetch, between 0 and GetGeomFieldCount() - 1.

Returns: a pointer to an internal field definition object or NULL if invalid index. This object should not be modified or freed by the application.

Since: GDAL 1.11

◆ GetGeomFieldDefn() [2/2]

const OGRGeomFieldDefn * OGRFeatureDefn::GetGeomFieldDefn ( int iGeomField ) const

virtual

Fetch geometry field definition.

This method is the same as the C function OGR_FD_GetGeomFieldDefn().

Parameters

iGeomField the geometry field to fetch, between 0 and GetGeomFieldCount() - 1.

Returns: a pointer to an internal field definition object or NULL if invalid index. This object should not be modified or freed by the application.

Since: GDAL 2.3

◆ GetGeomFieldIndex()

int OGRFeatureDefn::GetGeomFieldIndex ( const char * pszGeomFieldName ) const

virtual

Find geometry field by name.

The geometry field index of the first geometry field matching the passed field name (case insensitively) is returned.

This method is the same as the C function OGR_FD_GetGeomFieldIndex().

Parameters

pszGeomFieldName the geometry field name to search for.

Returns: the geometry field index, or -1 if no match found.

◆ GetGeomType()

OGRwkbGeometryType OGRFeatureDefn::GetGeomType ( ) const

virtual

Fetch the geometry base type.

Note that some drivers are unable to determine a specific geometry type for a layer, in which case wkbUnknown is returned. A value of wkbNone indicates no geometry is available for the layer at all. Many drivers do not properly mark the geometry type as 25D even if some or all geometries are in fact 25D. A few (broken) drivers return wkbPolygon for layers that also include wkbMultiPolygon.

Starting with GDAL 1.11, this method returns GetGeomFieldDefn(0)->GetType().

This method is the same as the C function OGR_FD_GetGeomType().

Returns: the base type for all geometry related to this definition.

◆ GetName()

const char * OGRFeatureDefn::GetName ( ) const

virtual

Get name of this OGRFeatureDefn.

This method is the same as the C function OGR_FD_GetName().

Returns: the name. This name is internal and should not be modified, or freed.

◆ GetReferenceCount()

int OGRFeatureDefn::GetReferenceCount ( ) const

inline

Fetch current reference count.

This method is the same as the C function OGR_FD_GetReferenceCount().

Returns: the current reference count.

◆ IsGeometryIgnored()

int OGRFeatureDefn::IsGeometryIgnored ( ) const

virtual

Determine whether the geometry can be omitted when fetching features.

This method is the same as the C function OGR_FD_IsGeometryIgnored().

Starting with GDAL 1.11, this method returns GetGeomFieldDefn(0)->IsIgnored().

Returns: ignore state

◆ IsSame()

int OGRFeatureDefn::IsSame ( const OGRFeatureDefn * poOtherFeatureDefn ) const

virtual

Test if the feature definition is identical to the other one.

Parameters

poOtherFeatureDefn the other feature definition to compare to.

Returns: TRUE if the feature definition is identical to the other one.

◆ IsStyleIgnored()

int OGRFeatureDefn::IsStyleIgnored ( ) const

inlinevirtual

Determine whether the style can be omitted when fetching features.

This method is the same as the C function OGR_FD_IsStyleIgnored().

Returns: ignore state

◆ Reference()

int OGRFeatureDefn::Reference ( )

inline

Increments the reference count by one.

The reference count is used keep track of the number of OGRFeature objects referencing this definition.

This method is the same as the C function OGR_FD_Reference().

Returns: the updated reference count.

◆ ReorderFieldDefns()

OGRErr OGRFeatureDefn::ReorderFieldDefns ( int * panMap )

virtual

Reorder the field definitions in the array of the feature definition.

To reorder the field definitions in a layer definition, do not use this function directly, but use OGR_L_ReorderFields() instead.

This method should only be called while there are no OGRFeature objects in existence based on this OGRFeatureDefn.

This method is the same as the C function OGR_FD_ReorderFieldDefns().

Parameters

panMap an array of GetFieldCount() elements which is a permutation of [0, GetFieldCount()-1]. panMap is such that, for each field definition at position i after reordering, its position before reordering was panMap[i].

Returns: OGRERR_NONE in case of success.

Since: OGR 1.9.0

◆ SetGeometryIgnored()

void OGRFeatureDefn::SetGeometryIgnored ( int bIgnore )

virtual

Set whether the geometry can be omitted when fetching features.

This method is the same as the C function OGR_FD_SetGeometryIgnored().

Starting with GDAL 1.11, this method calls GetGeomFieldDefn(0)->SetIgnored().

Parameters

bIgnore ignore state

◆ SetGeomType()

void OGRFeatureDefn::SetGeomType ( OGRwkbGeometryType eNewType )

virtual

Assign the base geometry type for this layer.

All geometry objects using this type must be of the defined type or a derived type. The default upon creation is wkbUnknown which allows for any geometry type. The geometry type should generally not be changed after any OGRFeatures have been created against this definition.

This method is the same as the C function OGR_FD_SetGeomType().

Starting with GDAL 1.11, this method calls GetGeomFieldDefn(0)->SetType().

Parameters

eNewType the new type to assign.

◆ SetName()

void OGRFeatureDefn::SetName ( const char * pszName )

Change name of this OGRFeatureDefn.

Parameters

pszName feature definition name

Since: GDAL 2.3

◆ SetStyleIgnored()

void OGRFeatureDefn::SetStyleIgnored ( int bIgnore )

inlinevirtual

Set whether the style can be omitted when fetching features.

This method is the same as the C function OGR_FD_SetStyleIgnored().

Parameters

bIgnore ignore state

◆ ToHandle()

static OGRFeatureDefnH OGRFeatureDefn::ToHandle ( OGRFeatureDefn * poFeatureDefn )

inlinestatic

Convert a OGRFeatureDefn* to a OGRFeatureDefnH.

Since: GDAL 2.3

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

ogr_feature.h
ogrfeaturedefn.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ OGRFeatureDefn()

Member Function Documentation

◆ AddFieldDefn()

◆ AddGeomFieldDefn()

◆ Clone()

◆ ComputeMapForSetFrom()

◆ CreateFeatureDefn()

◆ DeleteFieldDefn()

◆ DeleteGeomFieldDefn()

◆ Dereference()

◆ DestroyFeatureDefn()

◆ FromHandle()

◆ GetFieldCount()

◆ GetFieldDefn() [1/2]

◆ GetFieldDefn() [2/2]

◆ GetFieldIndex()

◆ GetFieldIndexCaseSensitive()

◆ GetGeomFieldCount()

◆ GetGeomFieldDefn() [1/2]

◆ GetGeomFieldDefn() [2/2]

◆ GetGeomFieldIndex()

◆ GetGeomType()

◆ GetName()

◆ GetReferenceCount()

◆ IsGeometryIgnored()

◆ IsSame()

◆ IsStyleIgnored()

◆ Reference()

◆ ReorderFieldDefns()

◆ SetGeometryIgnored()

◆ SetGeomType()

◆ SetName()

◆ SetStyleIgnored()

◆ ToHandle()