ElementsController

The Elements controller allows you to get information about the elements on the map, and make changes to their visibility.

Extended by

• FeltController

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"] });

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();