Class: IntervalRunner<TResult, TArgs>

Defined in: packages/rx/src/IntervalRunner.ts:109

A simple runner to execute a task periodically.

When to use IntervalRunner instead of IntervalSubject?

IntervalRunner is useful when the execution of the taskFn (and its onResult callback) needs to be precisely timed and/or excluded from the interval delay duration.

Examples

When an API call needs to be made periodically and there's a possibility of delayed response (due to network issues
or longer backend execution time). In this case, using IntervalRunner with `sequential = true` will ensure the
delay is consistent between completion of current and start of the next API call.

Execute a function sequentially

Counting time will not start until function execution ends, maintaining the delay between end of execution consistent.

import fetch from '@superutils/fetch'
import { IntervalRunner } from '@superutils/rx'

const runner = new IntervalRunner(
    fetch.get, // function to execute
	   ['[DUMMYJSON-DOT-COM]/products'], // arguments to be provided to the function on each execution
    2000,
 )
runner.start(result => console.log({ result }))

Execute a function without enforcing sequential completion

Timing begins at the start of the task, ensuring a consistent interval between the start of each execution, regardless of when the task finishes.

import fetch from '@superutils/fetch'
import { IntervalRunner } from '@superutils/rx'

// Create a interval runner that retrieves products every 2 seconds
const runner = new IntervalRunner(
  fetch.get,
	 ['[DUMMYJSON-DOT-COM]/products'],
  2000,
  false,
 )
runner.start(result => console.log({ result }))

Execute a function and auto-retry on failure

import fetch from '@superutils/fetch'
import { IntervalRunner } from '@superutils/rx'

const runner = new IntervalRunner(
  () => retry(
    fetch.get, // function to execute
    { retry: 3 }, // retry maximum 3 times (max 5 attempts )
  ),
	 ['[DUMMYJSON-DOT-COM]/products'], // arguments to be provided to the function on each execution
  2000,
 )
runner.start(result => console.log({ result }))

Param

taskFn

task function to be executed periodically

Param

taskArgs

arguments (or a function that returns arguments) to be supplied to the task function.

Param

intervalMs

timer delay in milliseconds.

Param

sequential

true (default): will use setTimeout and will delay until execution is completed. This will ensure, in case the current execution takes longer, the following execution will not occur until current one is done and the interval delay is passed.

false: will use setInterval and the delay time to execute task will not affected. This may cause unwanted issues if the execution takes longer than the interval delay time. Use with caution.

Default: true

Param

preExecute

(optional) if true, will pre-execute task before starting the timer.

Default: true

Type Parameters

TResult

TResult = unknown

TArgs

TArgs extends unknown[] = unknown[]

Constructors

Constructor

new IntervalRunner<TResult, TArgs>(taskFn, taskArgs, intervalMs, sequential?, preExecute?): IntervalRunner<TResult, TArgs>

Defined in: packages/rx/src/IntervalRunner.ts:126

Parameters

taskFn

(...args) => TResult | Promise<TResult>

taskArgs

TArgs | ((this, runCount) => TArgs)

intervalMs

number | BehaviorSubject<number>

sequential?

boolean = true

preExecute?

boolean = true

Returns

IntervalRunner<TResult, TArgs>

Properties

intervalMs$

readonly intervalMs$: BehaviorSubject<number>

Defined in: packages/rx/src/IntervalRunner.ts:121

RxJS BehaviorSubject to change timer delay (and restart the timer) on the fly

---

lastResult

lastResult: TResult | undefined

Defined in: packages/rx/src/IntervalRunner.ts:114

---

minIntervalMs

minIntervalMs: number = 1000

Defined in: packages/rx/src/IntervalRunner.ts:115

---

preExecute

readonly preExecute: boolean = true

Defined in: packages/rx/src/IntervalRunner.ts:136

---

sequential

readonly sequential: boolean = true

Defined in: packages/rx/src/IntervalRunner.ts:135

---

taskArgs

readonly taskArgs: TArgs | ((this, runCount) => TArgs)

Defined in: packages/rx/src/IntervalRunner.ts:128

---

taskFn

readonly taskFn: (...args) => TResult | Promise<TResult>

Defined in: packages/rx/src/IntervalRunner.ts:127

Parameters

args

...TArgs

Returns

TResult | Promise<TResult>

Accessors

runCount

Get Signature

get runCount(): number

Defined in: packages/rx/src/IntervalRunner.ts:214

Get number of times task has ran, excluding resets

Returns

number

Methods

executeOnce()

executeOnce(): Promise<TResult | undefined>

Defined in: packages/rx/src/IntervalRunner.ts:192

Executes the task function once, regardless of the interval runner's current state.

Returns

Promise<TResult | undefined>

---

isStarted()

isStarted(): boolean

Defined in: packages/rx/src/IntervalRunner.ts:196

Check if interval is running

Returns

boolean

---

restart()

restart(resetRunCount?): boolean

Defined in: packages/rx/src/IntervalRunner.ts:205

Restart interval

Parameters

resetRunCount?

boolean = false

(optional) whether to reset run count

Returns

boolean

indicates whether restart was successful

---

start()

start(onResult?, onBeforeExec?): boolean

Defined in: packages/rx/src/IntervalRunner.ts:229

Sets the onResult and onBeforeExec callbacks and starts the interval execution.

If the runner is already started, the new callbacks will be used for subsequent executions. To apply new callbacks immediately, call stop() first, then start(). In order to start using callbacks immediately, invoke the intervalRunner.stop() function first.

Parameters

onResult?

OnResultType<TResult>

(optional) function to be invoked whenever the task is succefully executed. See OnResultType

onBeforeExec?

onBeforeExecType

Returns

boolean

indicates whether starting interveral waa successful

---

stop()

stop(resetRunCount?): IntervalRunner<TResult, TArgs>

Defined in: packages/rx/src/IntervalRunner.ts:268

Stop interval runner

Parameters

resetRunCount?

boolean = false

(optional) whether to reset the run counter

Returns

IntervalRunner<TResult, TArgs>