Merge pull request #2 from luminos-software/master

Added method for continuously watching position updates

README.md

@@ -37,7 +37,7 @@ In the root saga spawn the channel watcher:
 
 ```javascript
 
-import {watchLocationChannel, getCurrentPosition} from 'redux-saga-location';
+import {watchLocationChannel, getCurrentPosition, watchCurrentPosition} from 'redux-saga-location';
 
 export default function * rootSaga() {
   yield [
@@ -49,6 +49,8 @@ export default function * rootSaga() {
 
 # Usage
 
+## Usage of getCurrentPosition
+
 We call `getCurrentPosition` according to the [web-standard-method](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation/getCurrentPosition) and (if user permits) the current position will be put into the redux store.
 
 ```javascript
@@ -57,6 +59,16 @@ yield call(getCurrentPosition)
 
 The received data is the same as from [navigator.geolocation.getCurrentPosition](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation/getCurrentPosition).
 
+## Usage of watchCurrentPosition
+
+We call `watchCurrentPosition` according to the [web-standard-method](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation/watchPosition) and (if user permits) the position will be put into the redux store as often as it gets updated.
+
+```javascript
+yield call(watchCurrentPosition)
+```
+
+The received data is the same as from [navigator.geolocation.watchPosition](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation/watchPosition).
+
 We can listen to the event in our reducers per "REDUX_SAGA_LOCATION_SET_POSITION", while errors can be detected with "REDUX_SAGA_LOCATION_SET_ERROR".
 
 If we want to use constans for the actions, we can import them with:

index.js

@@ -5,5 +5,5 @@
 
 'use strict';
 
-export { watchLocationChannel, getCurrentPosition } from './saga/location';
+export { watchLocationChannel, getCurrentPosition, watchCurrentPosition } from './saga/location';
 export { default as locationReducer } from './reducer/location';

saga/location.js

@@ -1,12 +1,13 @@
-
 import { channel } from 'redux-saga';
 import { take, put, call } from 'redux-saga/effects';
 
 export const locationChannel = channel()
 
-import {REDUX_SAGA_LOCATION_ACTION_SET_POSITION
-    , REDUX_SAGA_LOCATION_ACTION_SET_ERROR
-    , REDUX_SAGA_LOCATION_ACTION_REQUEST} from '../actions';
+import {
+  REDUX_SAGA_LOCATION_ACTION_SET_POSITION,
+  REDUX_SAGA_LOCATION_ACTION_SET_ERROR,
+  REDUX_SAGA_LOCATION_ACTION_REQUEST
+} from '../actions';
 
 export function * watchLocationChannel() {
   while (true) {
@@ -26,3 +27,13 @@ export function * getCurrentPosition(options) {
     );
 }
 
+export function * watchCurrentPosition(options) {
+    locationChannel.put({type: REDUX_SAGA_LOCATION_ACTION_REQUEST})
+    navigator.geolocation.watchPosition(
+      position => {
+        locationChannel.put({type: REDUX_SAGA_LOCATION_ACTION_SET_POSITION, position})
+      },
+      (error) => locationChannel.put({type: REDUX_SAGA_LOCATION_ACTION_SET_ERROR, error}),
+      options
+    );
+}