# MapSourceDataEvent

Defined in: [ui/events.ts:556](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L556>)

A `MapSourceDataEvent` is emitted with the source-related `data`, `dataloading`, `dataabort`, `sourcedata`, `sourcedataloading` and `sourcedataabort` events. Its `dataType` is always `'source'`.

Possible values for `sourceDataType`s are:

- `'metadata'`: indicates that any necessary source metadata has been loaded (such as TileJSON) and it is ok to start loading tiles
- `'content'`: indicates the source data has changed (such as when source.setData() has been called on GeoJSONSource)
- `'visibility'`: send when the source becomes used when at least one of its layers becomes visible in style sense (inside the layer's zoom range and with layout.visibility set to 'visible')
- `'idle'`: indicates that no new source data has been fetched (but the source has done loading)

## Example

```ts
// The sourcedata event is an example of a MapSourceDataEvent.
// Set up an event listener on the map.
map.on('sourcedata', (e) => {
   if (e.isSourceLoaded) {
       // Do something when the source has finished loading
   }
});
```

## Extends

- [`MapLibreEvent`](<https://maplibre.org/maplibre-gl-js/docs/API/classes/MapLibreEvent/index.md>)

## Properties

### coord

> **coord**: [`OverscaledTileID`](<https://maplibre.org/maplibre-gl-js/docs/API/interfaces/OverscaledTileID/index.md>)

Defined in: [ui/events.ts:578](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L578>)

The tile ID of the tile being loaded or changed, if the event is related to loading of a tile.

---

### isSourceLoaded

> **isSourceLoaded**: `boolean`

Defined in: [ui/events.ts:562](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L562>)

True if the event has a `dataType` of `source` and the source has no outstanding network requests.

---

### resourceTiming?

> `optional` **resourceTiming?**: `PerformanceResourceTiming`\[\]

Defined in: [ui/events.ts:582](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L582>)

Resource timing data, if `collectResourceTiming` is enabled for the source.

---

### source

> **source**: [`SourceSpecification`](<https://maplibre.org/maplibre-style-spec/sources/>)

Defined in: [ui/events.ts:566](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L566>)

The [style spec representation of the source](<https://maplibre.org/maplibre-style-spec/#sources>) if the event has a `dataType` of `source`.

---

### target

> **target**: [`Map`](<https://maplibre.org/maplibre-gl-js/docs/API/classes/Map/index.md>)

Defined in: [ui/events.ts:485](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L485>)

The object that fired the event. Set when the event is fired, and narrowed to a more specific type (e.g. `Map`, `Marker`) by the event subclasses.

#### Inherited from

[`MapLibreEvent`](<https://maplibre.org/maplibre-gl-js/docs/API/classes/MapLibreEvent/index.md>).[`target`](<https://maplibre.org/maplibre-gl-js/docs/API/classes/MapLibreEvent/#target>)

---

### tile

> **tile**: `any`

Defined in: [ui/events.ts:574](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/ui/events.ts#L574>)

The tile being loaded or changed, if the event has a `dataType` of `source` and the event is related to loading of a tile.