angular 9 observable.create example
Example 1: understanding Observable.create(
import { Observable } from "rxjs/Observable";
var observable = Observable.create(function subscribe(observer) {
observer.next('Hey guys!')
})
// OR
var observable = Observable.create((observer:any) => {
observer.next('Hey guys!')
})
Example 2: observable tutorial angular
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// Create an Observable that will start listening to geolocation updates
// when a consumer subscribes.
const locations = new Observable((observer) => {
let watchId: number;
// Simple geolocation API check provides values to publish
if ('geolocation' in navigator) {
watchId = navigator.geolocation.watchPosition((position: Position) => {
observer.next(position);
}, (error: PositionError) => {
observer.error(error);
});
} else {
observer.error('Geolocation not available');
}
// When the consumer unsubscribes, clean up data ready for next subscription.
return {
unsubscribe() {
navigator.geolocation.clearWatch(watchId);
}
};
});
// Call subscribe() to start listening for updates.
const locationsSubscription = locations.subscribe({
next(position) {
console.log('Current Position: ', position);
},
error(msg) {
console.log('Error Getting Location: ', msg);
}
});
// Stop listening for location after 10 seconds
setTimeout(() => {
locationsSubscription.unsubscribe();
}, 10000);