Scheduling Jobs

2 min

A relagit workflow begins runingn when the app is opened. You’ve already learnt how to run actions on certain events, but what if you want to run a task at a specific time? This is where cron jobs come in.

Setting up a cron job

relagit:workflows provides a helpful cron export to accomplish this. You can use it to schedule a task to run at a specific interval.

Scheduling a cron job
import { const cron: (<T extends number | TemplateStringsArray>(time: T) => T extends number ? {
    seconds: number;
    minutes: number;
    hours: number;
    days: number;
    months: number;
} : number) & {
    ...;
}
A utility to generate CRON timings.cron } from "relagit:actions";

let let duration: numberduration: number;

let duration: numberduration = cron<5>(time: 5): {
    seconds: number;
    minutes: number;
    hours: number;
    days: number;
    months: number;
}cron(5).hours: numberhours;
let duration: numberduration = const cron: (<T extends number | TemplateStringsArray>(time: T) => T extends number ? {
    seconds: number;
    minutes: number;
    hours: number;
    days: number;
    months: number;
} : number) & {
    ...;
}
A utility to generate CRON timings.cron`5 hours`; // also works

const cron: (<T extends number | TemplateStringsArray>(time: T) => T extends number ? {
    seconds: number;
    minutes: number;
    hours: number;
    days: number;
    months: number;
} : number) & {
    ...;
}
A utility to generate CRON timings.cron.schedule: (time: number, cb: () => void, proxy: RecordType) => void
Schedule a function to run at specific times.schedule(
    let duration: numberduration,
    () => {
        var console: Console
The `console` module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.

The module exports two specific components:

* A `Console` class with methods such as `console.log()`, `console.error()` and`console.warn()` that can be used to write to any Node.js stream.
* A global `console` instance configured to write to `process.stdout` and `process.stderr`. The global `console` can be used without calling`require('console')`.

_**Warning**_: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the `note on process I/O` for
more information.

Example using the global `console`:

```js
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
```

Example using the `Console` class:

```js
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
```
@see[source](https://github.com/nodejs/node/blob/v16.4.2/lib/console.js)console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to `stdout` with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to [`printf(3)`](http://man7.org/linux/man-pages/man3/printf.3.html) (the arguments are all passed to `util.format()`).

```js
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
```

See `util.format()` for more information.
@sincev0.1.100log("It's been 5 hours!");
    },
    let options: OptionsType<any>options,
);

If you want to run a task every 5 hours, you can use the cron function to get the duration in milliseconds. You can then pass this duration to cron.schedule along with a callback function to run.

If the app is closed and the cron job is scheduled to run, it will run the next time the app is opened.