# tasko
> Task sequencer
Latest version **0.3.0** (published 2021-03-05) · MIT license · 0 weekly downloads
## Install
```sh
npm install tasko
pnpm add tasko
yarn add tasko
bun add tasko
```
## Health
**Score 20/100 (F)** — status: abandoned.
Positive: esm support; no vulnerabilities.
Warnings: low downloads; no types; pre 1.0.
Negative: abandoned; low maintenance score.
## Facts
| | |
|---|---|
| Version | 0.3.0 |
| Published | 2021-03-05 |
| First published | 2017-10-21 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | ESM + CommonJS |
| Dependencies | 0 |
| Unpacked size | 57.5 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 2 |
| Author | DevSide |
| Maintainers | devside |
## Links
- npm: https://www.npmjs.com/package/tasko
- Repository: https://github.com/DevSide/tasko
- Homepage: https://github.com/DevSide/tasko#readme
- Issues: https://github.com/DevSide/tasko/issues
- npm.io page: https://npm.io/package/tasko
## Recent versions
- 0.3.0 (latest) — 2021-03-05
- 0.2.0 — 2019-04-29
- 0.1.3 — 2019-04-26
- 0.1.2 — 2019-03-31
- 0.1.1 — 2019-03-27
- 0.1.0 — 2019-03-26
- 0.0.2 — 2017-12-14
- 0.0.1 — 2017-10-21
## README
Tasko
Declarative task sequencer for Javascript
## Installation
```shell
yarn add tasko
npm install tasko
```
## Terminology
Tasko is inspired by Behavior tree' control flow. It doesn't rely on a time-based execution (tick).
### Task creators
A task creator is a function that creates a task.
#### Parameters
| Properties | Type | Details |
| ----------- | -------- | ------------------------------------------------------------------------------- |
| **success** | function | A callback function to notify the parent the task succeeded. |
| | | It takes an optional parameter to be propagated which simulate a **send** call. |
| **fail** | function | A callback function to notify the parent the task failed. |
| | | It takes an optional parameter to be propagated which simulate a **send** call. |
| **send** | function | A function to send something to the parent. |
| | | It takes an required parameter to be propagated. |
#### Returns
A Task.
### Tasks
A task is an object which can be run a process and/or be cancelled.
#### Properties
| Properties | Type | Details |
| ---------- | -------- | ------------------------------------------------------------------------- |
| **name** | string | Task name |
| **run** | function | Called by the parent to run the task with optional spread params |
| **cancel** | function | Called by the parent to cancel the task, before or after running the task |
#### Usage
```js
/**
* Create a successful task
*
* @param {function} success - The callback to succeed with an optional param
* @param {function} fail - The callback to fail with an optional param
* @param {function} message - Send a message to the parent
*
* @returns {object} - A task
*/
const createSuccessfulTask = (success, fail, send) => ({
name: 'success',
run(...params) {
send(`the task is running with params: ${JSON.stringify(params)}`)
success('success')
},
cancel: () => {
// noop
},
})
```
### Decorators
A **decorator** is a function which enhances the original task behavior.
#### Parameter
A task creator to enhance.
#### Returns
A task creator enhanced.
#### Usage
```js
/**
* Makes a task always succeeds
*
* @param {function} taskCreator - task creator to enhance
*
* @returns {function} - Enhanced task creator
*/
const alwaysSucceed = (taskCreator) => (succeed, _, send) => {
const task = taskCreator(succeed, succeed, send)
return {
...task,
name: decorateName('alwaysSucceed', task.name), // @alwaysSucceed(task-name)
}
}
```
See existing decoractors that you can use import https://github.com/DevSide/tasko/blob/master/src/decorator.js
### Composites
A **composite (or branch)** is a task which orchestrates other tasks with an execution mode and an exit condition.
#### Execution modes
It determined how a composite task should run its children.
- **serie**: one task after another
- **parallel**: only works if the tasks run asynchronously, serie otherwise
#### Exit conditions
It determined how a composite task will succeed or fail based on its children.
- **selector**: this task immediately succeeds if a child has succeeded, fails if all its children have failed
- **sequence**: this task immediately fails if a child has failed, succeeds if all its children have succeeded
- **all**: this task runs all its children, it fails if a child has failed, succeeds otherwise
#### Parameter
A (spread) list of task creators to execute.
#### Returns
A task creators.
#### Available composites
```js
import {
serieSequence,
serieSelector,
serieAll,
parallelSequence,
parallelSelector,
parallelAll,
} from 'tasko/composite'
```
#### Usage
```js
import { serieSequence } from 'tasko/composite'
import { noop } from 'tasko/util'
const think = (success, fail, send) => ({
name: 'think',
run() {
send(`I'm thinking`)
success('Done')
},
cancel: noop,
})
const thinkings = serieSequence(think, think)
thinkings(
() => console.log('Process succeeded !'),
() => console.log('Process failed !'),
// composites lift up every child messages sent, the 2nd argument is the unique child name
(message, taskName) => console.log(taskName + ':', message),
).run()
```
Logs
```
think: I'm thinking
think: Done
think: I'm thinking
think: Done
Process succeeded !
```
### More examples
---
_Source: https://npm.io/package/tasko · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._