meta library

Iterators and reducers (coordEach, featureEach, flattenEach, etc.) for traversing GeoJSON.

Classes

BBox
Please make sure, you arrange your parameters like this: Longitude 1, Latitude 1, Altitude 1 (optional), Longitude 2, Latitude 2, Altitude 2 (optional) You can either specify 4 or 6 parameters If you are using the default constructor with two dimensional positions (lng + lat only), please use the constructor like this: BBox(lng1, lat1, lng2, lat2);
CoordinateType
Coordinate types, following https://tools.ietf.org/html/rfc7946#section-4
Feature<T extends GeometryObject>
Feature, as specified here https://tools.ietf.org/html/rfc7946#section-3.2
FeatureCollection<T extends GeometryObject>
FeatureCollection, as specified here https://tools.ietf.org/html/rfc7946#section-3.3
GeoJSONObject
GeometryCollection
GeometryCollection, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.8
GeometryObject
GeometryType<T>
LineString
LineString, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.4
MultiLineString
MultiLineString, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.5
MultiPoint
MultiPoint, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.3
MultiPolygon
MultiPolygon, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.7
Point
Point, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.2
Polygon
Polygon, as specified here https://tools.ietf.org/html/rfc7946#section-3.1.6
Position
Please make sure, you arrange your parameters like this:

Extensions

FeatureCollectionOtherMembersExtension on FeatureCollection<GeometryObject>
Extension to add "other members" support specifically to FeatureCollection
FeatureOtherMembersExtension on Feature<GeometryObject>
Extension to add "other members" support specifically to Feature
GeoJSONObjectOtherMembersExtension on GeoJSONObject
Extension to add "other members" support to GeoJSONObject This follows RFC 7946 specification: "A GeoJSON object MAY have 'other members'. Implementations MUST NOT interpret foreign members as having any meaning unless part of an extension or profile."
GeometryObjectOtherMembersExtension on GeometryObject
Extension to add "other members" support specifically to GeometryObject

Functions

applyFilter(Map? properties, dynamic filter) → bool
applyFilter Takes a Map properties and a filter, Returns a bool indicating filter is applied to the properties.
clusterEach(FeatureCollection<GeometryObject> geojson, dynamic property, ClusterEachCallback callback) → void
clusterEach Takes a FeatureCollection, a dynamic property key/value used to create clusters, and a ClusterEachCallback method that takes (cluster, clusterValue, currentIndex) and Returns void. For example:
clusterReduce<T>(FeatureCollection<GeometryObject> geojson, dynamic property, ClusterReduceCallback<T> callback, dynamic initialValue) → T?
Reduces clusters in Features, similar to Iterable.reduce Takes a FeatureCollection geojson, a dynamic property, a GeoJSONObject's property key/value used to create clusters, a ClusterReduceCallback method, and an initialValue to use as the first argument to the first call of the callback. Returns the value that results from the reduction. For example:
coordAll(GeoJSONObject geojson) → List<Position?>
Gets all coordinates from any GeoJSONObject. Receives any GeoJSONObject Returns List<Position> For example:
coordEach(GeoJSONObject geoJSON, Function callback, [bool excludeWrapCoord = false]) → void
Iterates over coordinates in any geoJSONObject, similar to Iterable.forEach example:
coordReduce<T>(GeoJSONObject geojson, CoordReduceCallback<T> callback, T? initialValue, [bool excludeWrapCoord = false]) → T?
Reduces coordinates in any GeoJSONObject, similar to Iterable.reduce
createBins(FeatureCollection<GeometryObject> geojson, dynamic property) → Map<dynamic, List<int>>
createBins Takes a FeatureCollection geojson, and dynamic property key whose corresponding values of the Features will be used to create bins. Returns Map<String, List
extractOtherMembers(Map<String, dynamic> json, List<String> standardKeys) → Map<String, dynamic>
Utility to extract "other members" from GeoJSON objects according to RFC 7946 specification.
featureEach(GeoJSONObject geoJSON, FeatureEachCallback callback) → void
Iterates over features in any geoJSONObject, calling callback on each iteration. Similar to Iterable.forEach. For example:
featureReduce<T>(GeoJSONObject geojson, FeatureReduceCallback<T> callback, T? initialValue) → T?
Reduces features in any GeoJSONObject, similar to Iterable.reduce.
filterProperties(Map<String, dynamic> properties, List<String>? keys) → Map<String, dynamic>
filterProperties Takes Map<String, dynamic> properties, and List<String> keys used to filter Properties. Returns Map<String, dynamic> filtered Properties For example:
flattenEach(GeoJSONObject geoJSON, FlattenEachCallback callback) → void
Iterates over flattened features in any geoJSONObject, similar to Iterable.forEach, calling callback on each flattened feature
flattenReduce<T>(GeoJSONObject geojson, FlattenReduceCallback<T> callback, T? initialValue) → T?
Reduces flattened features in any GeoJSONObject, similar to Iterable.reduce. Takes a FeatureCollection, Feature, or GeometryType a FlattenReduceCallback method that takes (previousValue, currentFeature, featureIndex, multiFeatureIndex), an initialValue Value to use as the first argument to the first call of the callback. Returns the value that results from the reduction. For example:
geomEach(GeoJSONObject geoJSON, GeomEachCallback callback) → void
Iterates over each geometry in geoJSON, calling callback on each iteration. Similar to Iterable.forEach
geomReduce<T>(GeoJSONObject geoJSON, GeomReduceCallback<T> callback, T? initialValue) → T?
Reduces geometry in any GeoJSONObject, similar to Iterable.reduce.
getCluster(FeatureCollection<GeometryObject> geojson, dynamic filter) → FeatureCollection<GeometryObject>
Get Cluster Takes a FeatureCollection<Feature> and a dynamic filter used on GeoJSON properties to get Cluster. Returns a FeatureCollection single cluster filtered by GeoJSON Properties For example:
propEach(GeoJSONObject geoJSON, PropEachCallback callback) → void
Iterates over properties in any geoJSON object, calling callback on each iteration. Similar to Iterable.forEach
propertiesContainsFilter(Map properties, Map filter) → bool
Properties contains filter (does not apply deepEqual operations) Takes a Map properties value, and a Map filter and Returns bool if filter does equal the properties For example
propReduce<T>(GeoJSONObject geojson, PropReduceCallback<T> callback, T? initialValue) → T?
Reduces properties in any GeoJSONObject into a single value, similar to how Iterable.reduce works. However, in this case we lazily run the reduction, so List of all properties is unnecessary.
segmentEach(GeoJSONObject geojson, SegmentEachCallback callback, {bool combineNestedGeometries = true}) → void
Iterates over 2-vertex line segment in any GeoJSON object, similar to Iterable.forEach (Multi)Point geometries do not contain segments therefore they are ignored during this operation.
segmentReduce<T>(GeoJSONObject geojson, SegmentReduceCallback<T> callback, T? initialValue, {bool combineNestedGeometries = true}) → T?
Reduces 2-vertex line segment in any GeoJSON object, similar to Iterable.reduce (Multi)Point geometries do not contain segments therefore they are ignored during this operation.

Typedefs

ClusterEachCallback = dynamic Function(FeatureCollection<GeometryObject>? cluster, dynamic clusterValue, int? currentIndex)
ClusterEachCallback Takes a FeatureCollection, the cluster being processed, a clusterValue used to create cluster being processed, and the currentIndex, the index of current element being processed in the List. Starts at index 0 Returns void.
ClusterReduceCallback<T> = T? Function(T? previousValue, FeatureCollection<GeometryObject>? cluster, dynamic clusterValue, int? currentIndex)
ClusterReduceCallback The first time the callback function is called, the values provided as arguments depend on whether the reduce method has an initialValue argument.
CoordEachCallback = dynamic Function(Position? currentCoord, int? coordIndex, int? featureIndex, int? multiFeatureIndex, int? geometryIndex)
CoordReduceCallback<T> = T? Function(T? previousValue, Position? currentCoord, int? coordIndex, int? featureIndex, int? multiFeatureIndex, int? geometryIndex)
Callback for coordReduce
FeatureEachCallback = dynamic Function(Feature<GeometryObject> currentFeature, int featureIndex)
Callback for featureEach
FeatureReduceCallback<T> = T? Function(T? previousValue, Feature<GeometryObject> currentFeature, int featureIndex)
Callback for featureReduce
FlattenEachCallback = dynamic Function(Feature<GeometryType> currentFeature, int featureIndex, int multiFeatureIndex)
Callback for flattenEach
FlattenReduceCallback<T> = T? Function(T? previousValue, Feature<GeometryObject> currentFeature, int featureIndex, int multiFeatureIndex)
Callback for flattenReduce The first time the callback function is called, the values provided as arguments depend on whether the reduce method has an initialValue argument. If an initialValue is provided to the reduce method:
GeomEachCallback = dynamic Function(GeometryType? currentGeometry, int? featureIndex, Map<String, dynamic>? featureProperties, BBox? featureBBox, dynamic featureId)
GeomReduceCallback<T> = T? Function(T? previousValue, GeometryType? currentGeometry, int? featureIndex, Map<String, dynamic>? featureProperties, BBox? featureBBox, dynamic featureId)
Callback for geomReduce
LocalizedCoordEachCallback = dynamic Function(Position? currentCoord, int? coordIndex, int? featureIndex, int? multiFeatureIndex, int? geometryIndex, int? localCoordIndex)
PropEachCallback = dynamic Function(Map<String, dynamic>? currentProperties, int featureIndex)
Callback for propEach
PropReduceCallback<T> = T? Function(T? previousValue, Map<String, dynamic>? currentProperties, int featureIndex)
Callback for propReduce
SegmentEachCallback = dynamic Function(Feature<LineString> currentSegment, int featureIndex, int? multiFeatureIndex, int? geometryIndex, int segmentIndex)
SegmentEachCallback
SegmentReduceCallback<T> = T? Function(T? previousValue, Feature<LineString> currentSegment, T? initialValue, int featureIndex, int? multiFeatureIndex, int? geometryIndex, int segmentIndex)
Callback for segmentReduce