FeltController

This is the main interface for interacting with a Felt map.

This interface is composed of the various controllers, each having a different area of responsibility.

All the methods are listed here, but each controller is documented on its own to make it easier to find related methods and events.

Extends

• ViewportController.UiController.LayersController.ElementsController.SelectionController.InteractionsController

Properties

iframe

readonly iframe: null | HTMLIFrameElement

The iframe element containing the Felt map, if it is an embedded map.

Methods

getElement()

getElement(id: string): Promise<null | Element>

Get a single element from the map by its id.

Parameters

Returns

Promise<null | Element>

The requested element.

Example

const element = await felt.getElement("element-1");

getElementGeometry()

getElementGeometry(id: string): Promise<null | Geometry>

Get the geometry of an element.

Parameters

Returns

Promise<null | Geometry>

Example

const geometry = await felt.getElementGeometry("element-1");
console.log(geometry?.type, geometry?.coordinates);

getElements()

getElements(constraint?: GetElementsConstraint): Promise<(null | Element)[]>

Gets elements from the map, according to the constraints supplied. If no constraints are supplied, all elements will be returned.

Parameters

Returns

Promise<(null | Element)[]>

All elements on the map.

Remarks

The elements in the map, ordered by the order specified in Felt. This is not necessarily the order that they are drawn in, as Felt draws points above lines and lines above polygons, for instance.

Example

const elements = await felt.getElements();

getElementGroup()

getElementGroup(id: string): Promise<null | ElementGroup>

Get an element group from the map by its id.

Parameters

Returns

Promise<null | ElementGroup>

The requested element group.

Example

felt.getElementGroup("element-group-1");

getElementGroups()

getElementGroups(constraint?: GetElementGroupsConstraint): Promise<(null | ElementGroup)[]>

Gets element groups from the map, according to the filters supplied. If no constraints are supplied, all element groups will be returned in rendering order.

Parameters

Returns

Promise<(null | ElementGroup)[]>

The requested element groups.

Example

const elementGroups = await felt.getElementGroups({ ids: ["element-group-1", "element-group-2"] });

setElementGroupVisibility()

setElementGroupVisibility(visibility: SetVisibilityRequest): Promise<void>

Hide or show element groups with the given ids.

Parameters

Returns

Promise<void>

Example

felt.setElementGroupVisibility({ show: ["element-group-1", "element-group-2"], hide: ["element-group-3"] });

getLayer()

getLayer(id: string): Promise<null | Layer>

Get a single layer from the map by its id.

Parameters

Returns

Promise<null | Layer>

The requested layer.

Example

const layers = await felt.getLayer({ ids: ["layer-1", "layer-2"] });

getLayers()

getLayers(constraint?: GetLayersConstraint): Promise<(null | Layer)[]>

Gets layers from the map, according to the constraints supplied. If no constraints are supplied, all layers will be returned.

Parameters

Returns

Promise<(null | Layer)[]>

All layers on the map.

Remarks

The layers in the map, ordered by the order specified in Felt. This is not necessarily the order that they are drawn in, as Felt draws points above lines and lines above polygons, for instance.

Example

const layers = await felt.getLayers();

setLayerVisibility()

setLayerVisibility(visibility: SetVisibilityRequest): Promise<void>

Hide or show layers with the given ids.

Parameters

Returns

Promise<void>

Example

felt.setLayerVisibility({ show: ["layer-1", "layer-2"], hide: ["layer-3"] });

getLayerGroup()

getLayerGroup(id: string): Promise<null | LayerGroup>

Get a layer group from the map by its id.

Parameters

Returns

Promise<null | LayerGroup>

The requested layer group.

Example

felt.getLayerGroup("layer-group-1");

getLayerGroups()

getLayerGroups(constraint?: GetLayerGroupsConstraint): Promise<(null | LayerGroup)[]>

Gets layer groups from the map, according to the constraints supplied. If no constraints are supplied, all layer groups will be returned in rendering order.

Parameters

Returns

Promise<(null | LayerGroup)[]>

The requested layer groups.

Example

const layerGroups = await felt.getLayerGroups({ ids: ["layer-group-1", "layer-group-2"] });

setLayerGroupVisibility()

setLayerGroupVisibility(visibility: SetVisibilityRequest): Promise<void>

Hide or show layer groups with the given ids.

Parameters

Returns

Promise<void>

Example

felt.setLayerGroupVisibility({ show: ["layer-group-1", "layer-group-2"], hide: ["layer-group-3"] });

getLegendItem()

getLegendItem(id: LegendItemIdentifier): Promise<null | LegendItem>

Allows you to get the state of a single legend item.

Parameters

Returns

Promise<null | LegendItem>

Example

const legendItem = await felt.getLegendItem({
  id: "legend-item-1",
  layerId: "layer-1",
})

getLegendItems()

getLegendItems(constraint?: LegendItemsConstraint): Promise<(null | LegendItem)[]>

Allows you to obtain the state of several legend items, by passing in constraints describing which legend items you want.

If you do not pass any constraints, you will receive all legend items.

Parameters

Returns

Promise<(null | LegendItem)[]>

Example

const legendItems = await felt.getLegendItems({layerId: "layer-1"});

setLegendItemVisibility()

setLegendItemVisibility(visibility: {show: LegendItemIdentifier[];hide: LegendItemIdentifier[]; }): Promise<void>

Hide or show legend items with the given identifiers.

Parameters

Returns

Promise<void>

Example

felt.setLegendItemVisibility({
  show: [{layerId: "layer-group-1", id: "item-1-0"}],
  hide: [{layerId: "layer-group-2", id: "item-2-0"}],
})

getLayerFilters()

getLayerFilters(layerId: string): Promise<null | LayerFilters>

Get the filters for a layer.

Parameters

Returns

Promise<null | LayerFilters>

Remarks

The return type gives you the filters split up into the various sources that make up the overall filters for a layer.

Example

const filters = await felt.getLayerFilters("layer-1");
console.log(filters.combined, filters.style, filters.ephemeral, filters.components);

setLayerFilters()

setLayerFilters(params: {layerId: string;filters: Filters; }): Promise<void>

Sets the ephemeral filters for a layer.

Parameters

Returns

Promise<void>

Example

felt.setLayerFilters({
  layerId: "layer-1",
  filters: ["AREA", "gt", 30_000],
});

getRenderedFeatures()

getRenderedFeatures(params?: GetRenderedFeaturesConstraint): Promise<Feature[]>

Get the features that are currently rendered on the map in the viewport.

Note that this is explicitly about the features that are rendered, which isn't necessarily a complete list of all the features in the viewport. This is because of the way features are tiled: at low zoom levels or high feature densities, many features are omitted from what is rendered on the screen.

Parameters

Returns

Promise<Feature[]>

Example

const features = await felt.getRenderedFeatures();

getSelection()

getSelection(): Promise<EntityNode[]>

Gets the current selection as a list of entity identifiers.

Returns

Promise<EntityNode[]>

Example

const selection = await felt.getSelection();

updateUiControls()

updateUiControls(controls: UiControlsOptions): void

Updates the UI controls on the embedded map.

Parameters

Returns

void

setOnMapInteractionsUi()

setOnMapInteractionsUi(options: OnMapInteractionsOptions): void

Control the on-map UI shown when interacting with features and elements.

If you add your own click, selection or hover handlers you may want to disable various parts of the Felt UI. This method allows you to control the visibility of various parts of the UI that might otherwise be shown when people click or hover on things.

This does not affect selection. That means that selectable features and elements will still be selected when clicked.

Parameters

Returns

void

getViewport()

getViewport(): Promise<ViewportState>

Gets the current state of the viewport.

Returns

Promise<ViewportState>

setViewport()

setViewport(viewport: SetViewportCenterZoomParams): void

Moves the map to the specified location.

Parameters

Returns

void

Example

felt.setViewport({
  center: { latitude: 0, longitude: 0 },
  zoom: 10,
});

fitViewportToBounds()

fitViewportToBounds(bounds: ViewportFitBoundsParams): void

Fits the map to the specified bounds.

Parameters

Returns

void

Example

const west = -122.4194;
const south = 37.7749;
const east = -122.4194;
const north = 37.7749;
felt.fitViewportToBounds({ bounds: [west, south, east, north] });

Events

onElementChange()

onElementChange(args: {options: {id: string; };handler: (change: ElementChangeCallbackParams) => void; }): VoidFunction

Adds a listener for when an element changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onElementChange({
  options: { id: "element-1" },
  handler: ({element}) => console.log(element.id),
});

// later on...
unsubscribe();

onElementGroupChange()

onElementGroupChange(args: {options: {id: string; };handler: (change: ElementGroupChangeCallbackParams) => void; }): VoidFunction

Adds a listener for when an element group changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onElementGroupChange({
  options: { id: "element-group-1" },
  handler: elementGroup => console.log(elementGroup.id),
});

// later on...
unsubscribe();

onPointerClick()

onPointerClick(params: {handler: (event: MapInteractionEvent) => void; }): VoidFunction

Allows you to be notified the user clicks on the map.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onPointerClick({
  handler: (event) => console.log(event.center, event.features),
});

// later on...
unsubscribe();

onPointerMove()

onPointerMove(params: {handler: (event: MapInteractionEvent) => void; }): VoidFunction

Allows you to be notified the user moves the mouse over the map.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onPointerMove({
  handler: (event) => console.log(event.center, event.features),
});

// later on...
unsubscribe();

onLayerChange()

onLayerChange(args: {options: {id: string; };handler: (change: LayerChangeCallbackParams) => void; }): VoidFunction

Adds a listener for when a layer changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onLayerChange({
  options: { id: "layer-1" },
  handler: ({layer}) => console.log(layer.bounds),
});

// later on...
unsubscribe();

onLayerGroupChange()

onLayerGroupChange(args: {options: {id: string; };handler: (change: LayerGroupChangeCallbackParams) => void; }): VoidFunction

Adds a listener for when a layer group changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onLayerGroupChange({
  options: { id: "layer-group-1" },
  handler: ({layerGroup}) => console.log(layerGroup.id),
});

// later on...
unsubscribe();

onLegendItemChange()

onLegendItemChange(args: {options: LegendItemIdentifier;handler: (change: LegendItemChangeCallbackParams) => void; }): VoidFunction

Adds a listener for when a legend item changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onLegendItemChange({
  options: { layerId: "layer-1", id: "item-1-0" },
  handler: ({legendItem}) => console.log(legendItem.visible),
});

// later on...
unsubscribe();

onSelectionChange()

onSelectionChange(params: {handler: (change: {selection: EntityNode[]; }) => void; }): VoidFunction

Adds a listener for when the selection changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onSelectionChange({
  handler: ({selection}) => console.log(selection),
});

// later on...
unsubscribe();

onViewportMove()

onViewportMove(args: {handler: (viewport: ViewportState) => void; }): VoidFunction

Adds a listener for when the viewport changes.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onViewportMove({
  handler: viewport => console.log(viewport.center.latitude),
});

// later on...
unsubscribe();

onViewportMoveEnd()

onViewportMoveEnd(args: {handler: (viewport: ViewportState) => void; }): VoidFunction

Adds a listener for when the viewport move ends, which is when the user stops dragging or zooming the map, animations have finished, or inertial dragging ends.

Parameters

Returns

VoidFunction

A function to unsubscribe from the listener

Example

const unsubscribe = felt.onViewportMoveEnd({
  handler: viewport => console.log(viewport.center.latitude),
});

// later on...
unsubscribe();