## NavigationService

A service for calculating navigation between locations.  
Can be accessed by `nextbillion.maps.NavigationService` if you load SDK by CDN url.

### Methods

| Method |  |
| --- | --- |
| route | route(opt: [NavigationRequest](#interface-navigationrequest))<br>  <br>Parameters<br>  <br>1.  opt: [NavigationRequest](#interface-navigationrequest) A navigation query to be sent to the NavigationSerivce<br>  <br>Return Value: Promise<null\|[NavigationResult](#interface-navigationresult)\><br>  <br>Request navigation between an origin and a destination. |

## Interface NavigationRequest

A navigation query to be sent to the NavigationSerivce

### Properties

| Name |  |
| --- | --- |
| altCount Optional | Type: number<br>  <br>Sets the number of alternative routes to return. Default: `3` . |
| alternatives Optional | Type: boolean<br>  <br>If enabled, the API will return alternative routes.  <br>  <br>You can set the number of routes in the `altCount` property. Note: `altcount` will default to `3` if this is enabled. |
| apiKey Optional | Type: string<br>  <br>api key for the request |
| approaches Optional | Type: Array<[ApproachType](#constants-approachtype)\><br>  <br>A list indicating the side of the road from which to approach waypoints in a requested route. If provided, the number of approaches must be one more than the number of waypoints. |
| avoid Optional | Type: Array<[AvoidType](#constants-avoidtype)\><br>  <br>Setting this will ensure the route avoids ferry, tolls or highways. |
| bearings Optional | Type: Array<[NavigationBearingInfo](#interface-navigationbearinginfo)\><br>  <br>Limits the search to segments with given bearing in degrees towards true north in clockwise direction.  <br>  <br>Note: Number of bearings should be equal to the number of coordinates. |
| departureTime Optional | Type: number<br>  <br>This parameter sets the departure time in Unix epoch time seconds format. Unit: seconds. PS: This parameter is only supported in premium plan. |
| destination Optional | Type: [LngLatLike](./geography-and-geometry#LngLatLike-lnglatlike)<br>  <br>Destination is the ending coordinates of your route. Ensure that destination is a valid land location.  <br>  <br>\[This parameter is mandatory IF geometry parameter is not given\] |
| geometry Optional | Type: string<br>  <br>If this parameter is provided, the only other parameters which will be considered in the request are `geometry_type` , `lang` and `key` . The rest of the parameters will be ignored. |
| geometryType Optional | Type: [GeometryType](#constants-geometrytype)<br>  <br>Sets the output format of the route geometry in the response. Default: `polyline6` . |
| lang Optional | Type: string<br>  <br>language of the text instruction |
| mode Optional | Type: [TravelMode](#constants-travelmode) \| string<br>  <br>A parameter which which sets the transportation mode for the route. PS: Only the 4w/car profile is enabled by default. The other customised routing profiles are only supported in premium plan. |
| origin Optional | Type: [LngLatLike](./geography-and-geometry#LngLatLike-lnglatlike)<br>  <br>Origin is the starting point of your route. Ensure that origin is a valid land location.  <br>  <br>\[This parameter is mandatory IF geometry parameter is not given\] |
| overview Optional | Type: [OverviewType](#constants-overviewtype)<br>  <br>Output verbosity of overview (whole trip) geometry. Default: `full` . |
| session Optional | Type: string<br>  <br>Unique session ID. If set, the response will reuse cached trip characteristics. PS: This parameter is only supported in premium plan. |
| waypoints Optional | Type: Array<[LngLatLike](./geography-and-geometry#LngLatLike-lnglatlike)\><br>  <br>Waypoints are coordinates along the route between Origin and Destination. This is a pipe separated list of coordinate pairs.  <br>  <br>Default maximum limit is 200 |

## Interface NavigationResult

The navigation response retrieved from the navigation server.

### Properties

| Name |  |
| --- | --- |
| country_code Optional | Type: string |
| error_msg Optional | Type: string<br>  <br>error message if status is not 200. |
| routes Optional | Type: Array<[NavigationResponseRoute](#interface-navigationresponseroute)\><br>  <br>routes calculated. |
| status | Type: NBRequestStatus \| string<br>  <br>A string indicating the state of the response. This is a separate code than the HTTP status code. On normal valid responses, the value will be Ok. |

## Interface NavigationResponseRoute

### Properties

| Name |  |
| --- | --- |
| distance | Type: number<br>  <br>route driving distance.  <br>  <br>Unit: `meters` |
| distance_full Optional | Type: number |
| duration | Type: number<br>  <br>route driving duration.  <br>  <br>Unit: `seconds` |
| end_location Optional | Type: { latitude: number,longitude: number }<br>  <br>end location of route |
| geojson Optional | Type: { coordinates: Array<Array<number>> } |
| geometry Optional | Type: string<br>  <br>encoded geometry value for step in `polyline` or `polyline6` . |
| legs | Type: Array<[NavigationResponseLeg](#interface-navigationresponseleg)\><br>  <br>legs of route.  <br>  <br>Note: `waypoints` split `route` into `legs` |
| special_objects Optional | Type: any<br>  <br>special geospatial objects crossed along the trip. |
| start_location Optional | Type: { latitude: number,longitude: number }<br>  <br>start location of route |

## Interface NavigationResponseLeg

### Properties

| Name |  |
| --- | --- |
| distance | Type: { value: number }<br>  <br>leg driving distance.  <br>  <br>Unit: `meters` |
| duration | Type: { value: number }<br>  <br>leg driving duration.  <br>  <br>Unit: `seconds` |
| end_location Optional | Type: { latitude: number,longitude: number } |
| start_location Optional | Type: { latitude: number,longitude: number } |
| steps | Type: Array<[NavigationResponseLegStep](#interface-navigationresponselegstep)\> |

## Interface NavigationResponseLegStep

### Properties

| Name |  |
| --- | --- |
| distance | Type: { value: number }<br>  <br>leg driving distance.  <br>  <br>Unit: `meters` |
| duration | Type: { value: number }<br>  <br>leg driving duration.  <br>  <br>Unit: `seconds` |
| end_location | Type: { latitude: number,longitude: number } |
| geojson Optional | Type: { coordinates: Array<Array<number>> } |
| geometry Optional | Type: string |
| intersections Optional | Type: Array<StepIntersections> |
| maneuver Optional | Type: StepManeuver |
| name Optional | Type: string |
| reference Optional | Type: string |
| start_location | Type: { latitude: number,longitude: number } |

## Interface NavigationBearingInfo

### Properties

| Name |  |
| --- | --- |
| degree | Type: number |
| range | Type: number |

## Constants ApproachType

| Constants |  |
| --- | --- |
| CURB | route will arrive at the waypoint on the driving_side of the region |
| UNRESTRICTED | route can arrive at the waypoint from either side of the road |

## Constants AvoidType

| Constants |  |
| --- | --- |
| FERRY | Avoid ferry in route. |
| HIGHWAY | Avoid highway in route. |
| TOLL | Avoid toll in route. |

## Constants TravelMode

The transportation mode for the route.

| Constants |  |
| --- | --- |
| AUTO | default mode, same as car |
| CAR | car mode |
| TRUCK | truck mode |

## Constants GeometryType

Output format of the route geometry.

| Constants |  |
| --- | --- |
| GEOJSON | Geojson format geometry. |
| POLYLINE | Polyline format geometry. |
| POLYLINE_6 | Polyline6 format geometry. |

## Constants OverviewType

| Constants |  |
| --- | --- |
| FALSE | Not include overview in result |
| FULL | Include full info in oveview |
| SIMPLIFIED | Only inlude simplified info in overview |