React Native Leaflet Maps

A Leaflet map component without Expo or native code for React Native applications

Why Use This Library

This component is useful if you want to display HTML elements on an interactive map. Since the elements are standard HTML items, they can be SVG's, emojis, text, images, etc.

Additionally, the elements can even be animated, updated, and changed as required.

This library is a mix between https://github.com/reggie3/react-native-webview-leaflet and https://github.com/pavel-corsaghin/react-native-leaflet. Thanks to them. You don't need to have Expo and you can change the HTML displayed in the View if necessary

Why Not Use This Library

You may not want to use this library if you'd rather use Google map tiles and data vice the tiles and map data from Open Street Maps.

Installation

Install using npm or yarn like this:

npm install --save react-native-leaflet-maps

or

yarn add react-native-leaflet-maps

Usage

and import like so

import { LeafletView } from 'react-native-leaflet-maps';

A typical example is shown below:

<LeafletView
// Your props, see the list below
/>

Props

Property	Required	Type	Purpose
doDebug	optional	boolean	show debug information from the component containing the Leaflet map
renderLoading	optional	React.ReactElement	custom component displayed while the map is loading
onError	optional	function	Will receive an error event
onLoadEnd	optional	function	Called when map stops loading
onLoadStart	optional	function	Called when the map starts to load
onMessageReceived	required	function	This function receives messages in the form of a WebviewLeafletMessage object from the map
mapLayers	optional	MapLayer array	An array of map layers
mapMarkers	optional	MapMarker array	An array of map markers
mapShapes	optional	MapShape[]	An array of map shapes
mapCenterPosition	optional	{lat: [Lat], lng: [Lng]} object	The center position of the map. This coordinate will not be accurate if the map has been moved manually. However, calling the map's setMapCenterPosition function will cause the map to revert to this location
ownPositionMarker	optional	Marker	A special marker that has an ID of OWN_POSTION_MARKER_ID
zoom	optional	number	Desired zoom value of the map
injectedJavaScript	optional	string	Additional Javascript
androidHardwareAccelerationDisabled	optional	boolean	Disable hardware acceleration on Android

Example Marker

ownPositionMarker={{
    id: '1',
    coords: {lat: 36.00, lng, -76.00},
    icon: "❤️",
    size: [24, 24],
    animation: {
      name: AnimationType.BOUNCE,
      duration: ".5",
      delay: 0,
      interationCount: INFINITE_ANIMATION_ITERATIONS
    }
  }}

After loading, the map expects to receive an array of map layer information objects. A sample object showing a MapBox tile layer is shown below.

  {
    baseLayerName: 'OpenStreetMap',  // the name of the layer, this will be seen in the layer selection control
    baseLayerIsChecked: 'true',  // if the layer is selected in the layer selection control
    layerType: 'TileLayer',  // Optional: a MapLayerType enum specifying the type of layer see "Types of Layers" below. Defaults to TILE_LAYER
    baseLayer: true,
    // url of tiles
    url: `https://api.tiles.mapbox.com/v4/mapbox.streets/{z}/{x}/{y}.png?access_token=${mapboxToken}`,
    // attribution string to be shown for this layer
    attribution:
      '&amp;copy <a href=&quot;http://osm.org/copyright&quot;>OpenStreetMap</a> contributors'
  }

Types of Layers

export enum MapLayerType {
  IMAGE_LAYER = "ImageOverlay",
  TILE_LAYER = "TileLayer",
  VECTOR_LAYER = "VectorLayer",
  VIDEO_LAYER = "VideoOverlay",
  WMS_TILE_LAYER = "WMSTileLayer"
}

Communicating with the map

Listening for Events

This library supports map clicked, map marker clicked, and the map events that are exposed by Leaflet.

Leaflet Map Events

The following Map Events are passed to the function designated by the onMessageReceived prop.

export enum WebViewLeafletEvents {
  MAP_COMPONENT_MOUNTED = "MAP_COMPONENT_MOUNTED",
  MAP_READY = "MAP_READY",
  DOCUMENT_EVENT_LISTENER_ADDED = "DOCUMENT_EVENT_LISTENER_ADDED",
  WINDOW_EVENT_LISTENER_ADDED = "WINDOW_EVENT_LISTENER_ADDED",
  UNABLE_TO_ADD_EVENT_LISTENER = "UNABLE_TO_ADD_EVENT_LISTENER",
  DOCUMENT_EVENT_LISTENER_REMOVED = "DOCUMENT_EVENT_LISTENER_REMOVED",
  WINDOW_EVENT_LISTENER_REMOVED = "WINDOW_EVENT_LISTENER_REMOVED",
  ON_MOVE_END = "onMoveEnd",
  ON_MOVE_START = "onMoveStart",
  ON_MOVE = "onMove",
  ON_RESIZE = "onResize",
  ON_UNLOAD = "onUnload",
  ON_VIEW_RESET = "onViewReset",
  ON_ZOOM_END = "onZoomEnd",
  ON_ZOOM_LEVELS_CHANGE = "onZoomLevelsChange",
  ON_ZOOM_START = "onZoomStart",
  ON_ZOOM = "onZoom",
  ON_MAP_TOUCHED = "onMapClicked",
  ON_MAP_MARKER_CLICKED = "onMapMarkerClicked"
}

Events prefixed with "ON" will receive the below object containing information about the map

{
  center, // center of the map
    bounds, // the bounds of the map
    zoom; // the zoom level of the map
}

Creating Map Markers

{
  id: uuidV1(), // The ID attached to the marker. It will be returned when onMarkerClicked is called
  position: {lat: [LATITTUDE], lng: [LONGITUDE]}, // Latitude and Longitude of the marker
  icon: '🍇', // HTML element that will be displayed as the marker.  It can also be text or an SVG string.
  size: [32, 32],
  animation: {
    duration: getDuration(),
    delay: getDelay(),
    iterationCount,
    type: AnimationType.BOUNCE
  }
}

Adding Leaflet Geometry Layers to the Map

Thanks to @gotoglup for the PR adding leaflet geometry layers. A geometry layer can be added to the may by following the example below:

mapShapes={[
  {
    shapeType: MapShapeType.CIRCLE,
    color: "#123123",
    id: "1",
    center: { lat: 34.225727, lng: -77.94471 },
    radius: 2000
  }
]}

Available Animations

Marker animations can be specified by setting the animation.type of the marker object to an AnimationType enum. Values for AnimationType can be found in the models.ts file in the WebViewLeaflet directory of this project.

Animation Information

Animations are kept in the file markers.css They are just keyframe animations like this:

@keyframes spin {
  50% {
    transform: rotateZ(-20deg);
    animation-timing-function: ease;
  }
  100% {
    transform: rotateZ(360deg);
  }
}

NOTES

If you do some changes in the html folder, in the folder, you must run

npm run-script dist

OR

yarn dist

If you do some changes in the lib, you must run

npm run-script prepack

OR

yarn prepack

You can run an example from the dedicated folder. It use Expo however the lib itself don't need Expo.

## Changelog

### 0.1.0
    First release

## LICENSE

MIT