oneline

what it is

Oneline is a cron-like and not-cron-like pure schduler which is able to schedule tasks in a single line.

It allows you to schedule all the tasks in a single timer.

And it is a cron-like scheduler.

If you don't like cron, it also provides a object literal way to schedule tasks.

Lastly, it is pure js-lib, no other dependencies.

how to install

npm install @bayn/oneline

or

pnpm i @bayn/oneline

how to use

1. import

import { scheduleManager } from "oneline";

2. schedule If we try to write a task like this:

• Setup for every 3 seconds
• Push a hello message to the logs array
• Only run three times
• Name schdule "morning alert"

scheduleManager.createSchedule(
  "1/3 * * * * ?",
  (over) => {
    logs.push("hello");
    if (logs.length === 3) {
      over();
    }
  },
  "morning alert"
);

That's all.

And if you have no interest in cron:

scheduleManager.createSchedule(
  { s: [0], m: [1], h: [2], d: [3], M: [4], w: [5] },
  (over) => {
    logs.push("hello");
    if (logs.length === 3) {
      over();
    }
  },
  "morning alert"
);

In this case, we set a schedule with an object literal. It is very easy to understand.

key	value
s	second
m	minute
h	hour
d	day
M	month
w	week

The value of each key is an array of numbers.

The above code is equivalent to the cron expression 0 1 2 3 4 5.

It should run every day in April 3 at 2:01:00 AM and every week on Friday.

api

createSchedule

• cronExpression: string | object literal

• See the above section for details.

getSchedule

• name: string

• Get schedule by name.

deleteSchedule

• name: string

• Delete schedule by name.

about one-line

I used to use a lib called node-schedule. But it have some problems make it a little unstable(maybe caused by the very old node version) and it is not been maintained for a long time(about 2 years). So I wrote this lib to replace it.

contribution

If you have any idea or suggestion, please feel free to open an issue or pull request. And I am a newbee in cron, so if you have any better idea about improving cron expression, please tell me.