A Feature is a (partial) copy of a domain object. More...

#include <luciad/models/features/Feature.h>

Classes
class	Builder
	Allows the incremental creation of a Feature object. More...

Public Member Functions
Builder	asBuilder () const
	Returns this Feature as a Feature::Builder. More...

std::shared_ptr< Geometry >	findGeometry () const
	Tries to find a geometry for this feature. More...

const DataType &	getDataType () const
	Returns the data type describing the feature properties. More...

FeatureId	getId () const
	Returns the id of this feature. More...

template<typename T >
std::optional< T >	getValue (const DataPropertyPath &propertyPath) const
	Accesses the value for the given property. More...

bool	hasId () const
	Returns if this Feature has an id. More...

bool	operator!= (const Feature &other) const

bool	operator== (const Feature &other) const

Static Public Member Functions
static Builder	newBuilder ()
	Returns a new Feature Builder. More...

Detailed Description

A Feature is a (partial) copy of a domain object.

It allows the rest of the API to easily access the domain object's properties, including any geometry. If you do a query on the model, and retrieve a Feature from it, the caller of the query receives ownership of the Feature. I.e. the caller can decide what to do with it, and when to dispose it.

This means that the Map and Layer API's are allowed to keep references to a Feature and have unrestricted lock-less access to its properties. The caller of the IFeatureModel::query method is responsible for managing the lifetime of a Feature.

To make Feature instances easy to use in a multi-threaded environment, they are

immutable
thread safe for reading

See article for more details on this class.

Member Function Documentation

◆ asBuilder()

Builder luciad::Feature::asBuilder ( ) const

Returns this Feature as a Feature::Builder.

This makes it possible to copy a Feature, and modify values. Note that when using this builder, it is not possible to change the datatype. Only the values and the id of the Feature. Otherwise a LogicException will be thrown.

Returns: this Feature as a Feature::Builder.

Since: 2020.1

◆ findGeometry()

std::shared_ptr< Geometry > luciad::Feature::findGeometry ( ) const

Tries to find a geometry for this feature.

If this feature's data type is annotated with GeometryDataAnnotation, the value of the corresponding property is returned. Otherwise, the result will be nullptr.

Returns: the annotated geometry, if any, else nullptr.

See also: GeometryDataAnnotation::getPropertyPath

◆ getDataType()

const DataType & luciad::Feature::getDataType ( ) const

Returns the data type describing the feature properties.

Returns: the data type describing the feature properties.

◆ getId()

FeatureId luciad::Feature::getId ( ) const

Returns the id of this feature.

A feature id should be unique across a model.

When no id is set, this method will throw an exception.

Returns: the id of this feature.

Exceptions

LogicException when the feature has no id.

◆ getValue()

template<typename T >

std::optional< T > luciad::Feature::getValue ( const DataPropertyPath & propertyPath ) const

Accesses the value for the given property.

Example

  auto optBool = feature.getValue<bool>(boolPropertyPath);
  auto optInt = feature.getValue<int32_t>(intPropertyPath);
  auto optLong = feature.getValue<int64_t>(longPropertyPath);
  auto optFloat = feature.getValue<float>(floatPropertyPath);
  auto optDouble = feature.getValue<double>(doublePropertyPath);
  auto optString = feature.getValue<std::string>(stringPropertyPath);
  auto optGeometry = feature.getValue<std::shared_ptr<Geometry>>(geometryPropertyPath);
  auto unsetValue = feature.getValue<std::string>(unsetPropertyPath); // Unset property -> empty optional

Template Parameters

T	the supported types are `bool`, `int32_t`, `int64_t`, `float`, `double`, `std::string`, `std::shared_ptr<luciad::Geometry>` or a subtype of `Geometry`.

Parameters

propertyPath the property for which to return a value

Returns: the value for the given property. If the property does exist in the DataType, but is not set for this particular feature, std::nullopt is returned.

Exceptions

InvalidArgumentException when the property is not of a known type, if it doesn't exist in the DataType, or when the type of the value doesn't correspond with the provided type parameter (for example when the property value is a Point geometry, but it is requested using ArcBand as type parameter).

◆ hasId()

bool luciad::Feature::hasId ( ) const

Returns if this Feature has an id.

If this method returns false, it is not allowed to call Feature::getId.

Returns: if this Feature has an id.

See also: Feature::Builder::id

◆ newBuilder()

static Builder luciad::Feature::newBuilder ( )

static

Returns a new Feature Builder.

Returns: a new Feature Builder.

◆ operator!=()

bool luciad::Feature::operator!= ( const Feature & other ) const

◆ operator==()

bool luciad::Feature::operator== ( const Feature & other ) const

Classes

Public Member Functions

Static Public Member Functions