## [FeatureLayer](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureLayer) interface interface `google.maps.FeatureLayer` An interface representing a map layer containing features of a specific `FeatureType` whose style can be overridden client-side, or have events attached. | ### Properties || |---|---| | `featureType` | **Type:** `FeatureType` The `FeatureType` associated with this `FeatureLayer`. | | `isAvailable` | **Type:** `boolean` Whether this `FeatureLayer` is available, meaning whether Data-driven styling is available for this map (there is a map ID using vector tiles with this `FeatureLayer` enabled in the Google Cloud Console map style.) If this is false (or becomes false), styling on this `FeatureLayer` returns to default and events are not triggered. | | `datasetId` optional | > [!WARNING] > **Notice:** Available only in the [v=beta channel](https://developers.google.com/maps/documentation/javascript/versions.md.txt#choosing-the-beta-channel). **Type:** `string optional` The Dataset ID for this `FeatureLayer`. Only present if the `featureType` is `FeatureType.DATASET`. | | `style` optional | **Type:** `FeatureStyleOptions|FeatureStyleFunction optional` The style of `Feature`s in the `FeatureLayer`. The style is applied when style is set. If your style function updates, you must set the style property again. A `FeatureStyleFunction` must return consistent results when it is applied over the map tiles, and should be optimized for performance. Asynchronous functions are not supported. If you use a `FeatureStyleOptions`, all features of that layer will be styled with the same `FeatureStyleOptions`. Set the style to `null` to remove the previously set style. If this `FeatureLayer` is not available, setting style does nothing and logs an error. | | ### Methods || |---|---| | `addListener` | `addListener(eventName, handler)` **Parameters:** - `eventName: string` Observed event. - `handler: Function` Function to handle events. **Return Value:** `MapsEventListener` Resulting event listener. Adds the given listener function to the given event name. Returns an identifier for this listener that can be used with `event.removeListener`. | | ### Events || |---|---| | `click` | `function(event)` **Arguments:** - `event: FeatureMouseEvent` This event is fired when the `FeatureLayer` is clicked. | | `mousemove` | `function(event)` **Arguments:** - `event: FeatureMouseEvent` This event is fired when the user's mouse moves over the `FeatureLayer`. | ## [FeatureType](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureType) constants constants `google.maps.FeatureType` library `"maps"` Identifiers for feature types. These constants are also usable as strings. In TypeScript, the string literals are defined by the `FeatureTypeString` type. ```javascript const {FeatureType} = await google.maps.importLibrary("maps"); ``` | ### Constants || |---|---| | `ADMINISTRATIVE_AREA_LEVEL_1` | Indicates a first-order civil entity below the country level. | | `ADMINISTRATIVE_AREA_LEVEL_2` | Indicates a second-order civil entity below the country level. | | `COUNTRY` | Indicates the national political entity. | | `DATASET` | > [!WARNING] > **Notice:** Available only in the [v=beta channel](https://developers.google.com/maps/documentation/javascript/versions.md.txt#choosing-the-beta-channel). Indicates a third-party dataset. | | `LOCALITY` | Indicates an incorporated city or town political entity. | | `POSTAL_CODE` | Indicates a postal code as used to address postal mail within the country. Includes zip codes. | | `SCHOOL_DISTRICT` | Indicates a school district. | ## [FeatureStyleFunction](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureStyleFunction) typedef typedef `google.maps.FeatureStyleFunction` A function to style a `FeatureLayer`. `function(FeatureStyleFunctionOptions): (FeatureStyleOptions optional)` ## [FeatureStyleFunctionOptions](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureStyleFunctionOptions) interface interface `google.maps.FeatureStyleFunctionOptions` Options passed to a `FeatureStyleFunction`. | ### Properties || |---|---| | `feature` | **Type:** `Feature` `Feature` passed into the `FeatureStyleFunction` for styling. | ## [FeatureStyleOptions](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureStyleOptions) interface interface `google.maps.FeatureStyleOptions` These options specify the way the style of a `Feature` should be modified on a map. | ### Properties || |---|---| | `fillColor` optional | **Type:** `string optional` Hex RGB string (like "#00FF00" for green). Only applies to polygon geometries. | | `fillOpacity` optional | **Type:** `number optional` The fill opacity between 0.0 and 1.0. Only applies to polygon geometries. | | `strokeColor` optional | **Type:** `string optional` Hex RGB string (like "#00FF00" for green). | | `strokeOpacity` optional | **Type:** `number optional` The stroke opacity between 0.0 and 1.0. Only applies to line and polygon geometries. | | `strokeWeight` optional | **Type:** `number optional` The stroke width in pixels. Only applies to line and polygon geometries. | ## [Feature](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#Feature) interface interface `google.maps.Feature` extended by `DatasetFeature, PlaceFeature` An interface representing a vector map tile feature. These are inputs to the `FeatureStyleFunction`. Do not save a reference to a particular `Feature` object because the reference will not be stable. | ### Properties || |---|---| | `featureType` | **Type:** `FeatureType` `FeatureType` of this `Feature`. | ## [PlaceFeature](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#PlaceFeature) interface interface `google.maps.PlaceFeature` extends `Feature` An interface representing a feature with a place ID which includes features of type `FeatureType.ADMINISTRATIVE_AREA_LEVEL_1`, `FeatureType.ADMINISTRATIVE_AREA_LEVEL_2`, `FeatureType.COUNTRY`, `FeatureType.LOCALITY`, `FeatureType.POSTAL_CODE`, and `FeatureType.SCHOOL_DISTRICT`. | ### Properties || |---|---| | `placeId` | **Type:** `string` The `PlaceResult.place_id`. | | ### Methods || |---|---| | `fetchPlace` | `fetchPlace()` **Parameters:** None **Return Value:** `Promise` Fetches a `Place` for this `PlaceFeature`. In the resulting `Place` object, the `id` and the `displayName` properties will be populated. The display name will be in the language the end user sees on the map. (Additional fields can be subsequently requested via `Place.fetchFields()` subject to normal Places API enablement and billing.) Do not call this from a `FeatureStyleFunction` since only synchronous FeatureStyleFunctions are supported. The promise is rejected if there was an error fetching the `Place`. | ## [DatasetFeature](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#DatasetFeature) interface interface `google.maps.DatasetFeature` extends `Feature` > [!WARNING] > **Notice:** Available only in the [v=beta channel](https://developers.google.com/maps/documentation/javascript/versions.md.txt#choosing-the-beta-channel). An interface representing a feature from a Dataset. The `featureType` of a `DatasetFeature` will always be `FeatureType.DATASET`. | ### Properties || |---|---| | `datasetAttributes` | **Type:** `Object` Key-value mapping of the feature's attributes. | | `datasetId` | **Type:** `string` Dataset id of the dataset that this feature belongs to. | ## [FeatureMouseEvent](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureMouseEvent) interface interface `google.maps.FeatureMouseEvent` extends `MapMouseEvent` This object is returned from a mouse event on a `FeatureLayer`. | ### Properties || |---|---| | `features` | **Type:** `Array` The `Feature`s at this mouse event. | | ### Methods || |---|---|