Every new change

node_modules/rxjs/src/internal/observable/timer.ts

@@ -0,0 +1,101 @@
+import { Observable } from '../Observable';
+import { SchedulerAction, SchedulerLike } from '../types';
+import { async } from '../scheduler/async';
+import { isNumeric } from '../util/isNumeric';
+import { isScheduler } from '../util/isScheduler';
+import { Subscriber } from '../Subscriber';
+
+/**
+ * Creates an Observable that starts emitting after an `dueTime` and
+ * emits ever increasing numbers after each `period` of time thereafter.
+ *
+ * <span class="informal">Its like {@link index/interval}, but you can specify when
+ * should the emissions start.</span>
+ *
+ * ![](timer.png)
+ *
+ * `timer` returns an Observable that emits an infinite sequence of ascending
+ * integers, with a constant interval of time, `period` of your choosing
+ * between those emissions. The first emission happens after the specified
+ * `dueTime`. The initial delay may be a `Date`. By default, this
+ * operator uses the {@link asyncScheduler} {@link SchedulerLike} to provide a notion of time, but you
+ * may pass any {@link SchedulerLike} to it. If `period` is not specified, the output
+ * Observable emits only one value, `0`. Otherwise, it emits an infinite
+ * sequence.
+ *
+ * ## Examples
+ * ### Emits ascending numbers, one every second (1000ms), starting after 3 seconds
+ * ```ts
+ * import { timer } from 'rxjs';
+ *
+ * const numbers = timer(3000, 1000);
+ * numbers.subscribe(x => console.log(x));
+ * ```
+ *
+ * ### Emits one number after five seconds
+ * ```ts
+ * import { timer } from 'rxjs';
+ *
+ * const numbers = timer(5000);
+ * numbers.subscribe(x => console.log(x));
+ * ```
+ * @see {@link index/interval}
+ * @see {@link delay}
+ *
+ * @param {number|Date} [dueTime] The initial delay time specified as a Date object or as an integer denoting
+ * milliseconds to wait before emitting the first value of 0`.
+ * @param {number|SchedulerLike} [periodOrScheduler] The period of time between emissions of the
+ * subsequent numbers.
+ * @param {SchedulerLike} [scheduler=async] The {@link SchedulerLike} to use for scheduling
+ * the emission of values, and providing a notion of "time".
+ * @return {Observable} An Observable that emits a `0` after the
+ * `dueTime` and ever increasing numbers after each `period` of time
+ * thereafter.
+ * @static true
+ * @name timer
+ * @owner Observable
+ */
+export function timer(dueTime: number | Date = 0,
+                      periodOrScheduler?: number | SchedulerLike,
+                      scheduler?: SchedulerLike): Observable<number> {
+  let period = -1;
+  if (isNumeric(periodOrScheduler)) {
+    period = Number(periodOrScheduler) < 1 && 1 || Number(periodOrScheduler);
+  } else if (isScheduler(periodOrScheduler)) {
+    scheduler = periodOrScheduler as any;
+  }
+
+  if (!isScheduler(scheduler)) {
+    scheduler = async;
+  }
+
+  return new Observable(subscriber => {
+    const due = isNumeric(dueTime)
+      ? (dueTime as number)
+      : (+dueTime - scheduler.now());
+
+    return scheduler.schedule(dispatch, due, {
+      index: 0, period, subscriber
+    });
+  });
+}
+
+interface TimerState {
+  index: number;
+  period: number;
+  subscriber: Subscriber<number>;
+}
+
+function dispatch(this: SchedulerAction<TimerState>, state: TimerState) {
+  const { index, period, subscriber } = state;
+  subscriber.next(index);
+
+  if (subscriber.closed) {
+    return;
+  } else if (period === -1) {
+    return subscriber.complete();
+  }
+
+  state.index = index + 1;
+  this.schedule(state, period);
+}