MGLVectorSource
@interface MGLVectorSource : MGLTileSource
MGLVectorSource
is a map content source that supplies tiled vector data in
Mapbox Vector Tile format to
be shown on the map. The location of and metadata about the tiles are defined
either by an option dictionary or by an external file that conforms to the
TileJSON specification.
A vector source is added to an MGLStyle
object along with one or more
MGLVectorStyleLayer
objects. A vector style layer defines the appearance of
any content supplied by the vector source.
Each
vector
source defined by the style JSON file is represented at runtime by an
MGLVectorSource
object that you can use to initialize new style layers. You
can also add and remove sources dynamically using methods such as
-[MGLStyle addSource:]
and -[MGLStyle sourceWithIdentifier:]
.
Within each vector tile, each geometric coordinate must lie between
−1 × extent and
(extent × 2) − 1, inclusive. Any vector style
layer initialized with a vector source must have a non-nil
value in its
sourceLayerIdentifier
property.
Commonly used vector sources include Mapbox Streets, Mapbox Terrain, and Mapbox Traffic.
Example
let source = MGLVectorSource(identifier: pois
, tileURLTemplates: [https://example.com/vector-tiles/{z}/{x}/{y}.mvt
], options: [
.minimumZoomLevel: 9,
.maximumZoomLevel: 16,
.attributionInfos: [
MGLAttributionInfo(title: NSAttributedString(string: © Mapbox
), url: URL(string: http://mapbox.com
))
]
])
mapView.style?.addSource(source)
-
Returns an array of map features loaded by this source, restricted to the given source layers and filtered by the given predicate.
Each object in the returned array represents a feature loaded by the source and provides access to attributes specified as part of the loaded feature. The source loads a feature if the source is added to an
MGLMapView
’s style; that style has a layer that uses the source; and the map view has recently scrolled to the region containing the feature.Features come from tiled vector data that is converted to tiles internally, so feature geometries are clipped at tile boundaries and features may appear duplicated across tiles. For example, suppose part of a lengthy polyline representing a road has recently scrolled into view. The resulting array includes those parts of the road that lie within the map tiles that the source has loaded, even if the road extends into other tiles. The portion of the road within each map tile is included individually.
Returned features may not necessarily be visible to the user at the time they are loaded: the style may contain a layer that forces the source’s tiles to load but filters out the features in question, preventing them from being drawn. To obtain only visible features, use the
-[MGLMapView visibleFeaturesAtPoint:inStyleLayersWithIdentifiers:predicate:]
or-[MGLMapView visibleFeaturesInRect:inStyleLayersWithIdentifiers:predicate:]
method.Declaration
Objective-C
- (nonnull NSArray<id<MGLFeature>> *) featuresInSourceLayersWithIdentifiers: (nonnull NSSet<NSString *> *)sourceLayerIdentifiers predicate:(nullable NSPredicate *)predicate;
Swift
func features(sourceLayerIdentifiers: Set
Parameters
sourceLayerIdentifiers
The source layers to include in the query. Only the features contained in these source layers are included in the returned array. This array may not be empty.
predicate
A predicate to filter the returned features. Use
nil
to include all loaded features.Return Value
An array of objects conforming to the
MGLFeature
protocol that represent features loaded by the source that match the predicate.