Selection

Overview

useSelection(name, options) extends the core useSelection composable with map-specific selection behaviour. Items in the selection store represent { location, feature, layer } triplets. The composable registers click, box-selection, and cluster-selection handlers on the current map activity and keeps the selection in sync with real-time service events on visible layers.

Usage

import { useSelection } from '@kalisio/kdk/map.client'

const {
  selection, selectItem, clearSelection,
  hasSelectedFeature, getSelectedFeature, getSelectedLayer,
  hasSelectedLocation, getSelectedLocation,
  centerOnSelection, getWidgetForSelection
} = useSelection('myMap', { boxSelection: true })

Parameters

Parameter	Type	Default	Description
name	string	—	Unique selection store name within the application.
options.multiple	string	'ctrlKey'	Name of the keyboard modifier property that activates multi-selection (e.g. 'ctrlKey', 'shiftKey').
options.buffer	number	10	Selection buffer radius in pixels used in buffer selection mode.
options.showBuffer	boolean	false	When true, briefly renders the buffer circle on the map after a buffer-mode click.
options.showBufferDelay	number	250	Duration in milliseconds to show the buffer circle.
options.boxSelection	boolean	true	When true, enables rectangular box-selection on the map.
options.clusterSelection	boolean	false	When true, selects all features of a cluster when a cluster marker is clicked (spiderfied).
options.handler	Function	—	Custom selection handler (items, clearSelection). When provided, replaces the built-in handler.

Exposed

All values from the core useSelection are exposed, plus:

Name	Type	Description
getSelectionOptions()	Function	Returns the resolved options object stored in the selection store.
setCurrentActivity(activity)	Function	Binds the composable to a new map activity instance. Removes listeners from the previous activity.
hasSelectedFeature()	Function	Returns true if the last selected item has a feature property.
getSelectedFeature()	Function	Returns the feature of the last selected item.
getSelectedFeatures()	Function	Returns all selected features (items that have a feature).
getSelectedFeatureCollection()	Function	Returns selected features as a GeoJSON FeatureCollection.
getSelectedFeaturesByLayer()	Function	Returns selected features grouped by layer as [{ layer, features }].
hasSelectedLayer()	Function	Returns true if the last selected item has a layer property.
getSelectedLayer()	Function	Returns the layer of the last selected item.
getSelectedLayers()	Function	Returns all layers associated with selected items.
hasSelectedLocation()	Function	Returns true if the last selected item has a location property.
getSelectedLocation()	Function	Returns the location of the last selected item.
getWidgetForSelection()	Function	Returns the widget type string to display for the current selection (e.g. 'time-series', 'information-box', 'mapillary-viewer').
centerOnSelection()	Function	Centers the map view on the currently selected feature or location.
setBoxSelectionEnabled(enabled)	Function	Dynamically enables or disables box selection.
setClusterSelectionEnabled(enabled)	Function	Dynamically enables or disables cluster selection.
setBufferWidth(width)	Function	Sets the buffer selection radius in pixels.

Lifecycle

• Registers click, boxselectionend, and spiderfied engine event handlers on the active map activity.
• Listens to layer-added / layer-removed events to track real-time service events on feature layers.
• Automatically unselects features that belong to a hidden layer (layer-hidden event).
• When the activity changes via setCurrentActivity, all listeners are migrated to the new activity.