movenext

Simple and straightforward solution to get the next logical record.

Live Demo

https://serhat-m.github.io/moveNext

Install

npm i movenext

Usage

Function moveNext(opts)

import moveNext from "movenext"

opts Object

• data { [key: string]: unknown }[] array of records
• direction 'prev' | 'next' determines the direction
• endBehaviour 'default' | 'jump' behaviour after the last logical entry
• selector(entry) => unknown callback for selecting the id reference
  • entry { [key: string]: unknown } entry of data
• selectedId undefined | ... current selected id

@returns new selected id

Example

This example navigates through the data Array, if the keyboard keys ArrowDown or ArrowUp are pressed. The selectedId variable saves the current state.

import moveNext from "movenext"

const data = [
  { id: 1, title: "Dataset 1" },
  { id: 2, title: "Dataset 2" },
  { id: 3, title: "Dataset 3" },
]

let selectedId = undefined

document.addEventListener("keydown", (event) => {
  const direction = event.key === "ArrowDown" ? "next" : event.key === "ArrowUp" ? "prev" : false

  if (direction) {
    selectedId = moveNext({
      data,
      direction,
      endBehaviour: "default",
      selector: (entry) => entry.id,
      selectedId,
    })
  }
})

Example React

import moveNext from "movenext"

const [data, setData] = useState([
  { id: 1, title: "Dataset 1" },
  { id: 2, title: "Dataset 2" },
  { id: 3, title: "Dataset 3" },
])

const [selectedId, setSelectedId] = useState(undefined)

const keyDownHandler = useCallback(
  (event) => {
    const direction = event.key === "ArrowDown" ? "next" : event.key === "ArrowUp" ? "prev" : false

    if (direction) {
      setSelectedId((prevSelectedId) => {
        return moveNext({
          data,
          direction,
          endBehaviour: "default",
          selector: (entry) => entry.id,
          selectedId: prevSelectedId,
        })
      })
    }
  },
  [data],
)

useEffect(() => {
  document.addEventListener("keydown", keyDownHandler)

  return () => {
    document.removeEventListener("keydown", keyDownHandler)
  }
}, [keyDownHandler])

TypeScript

The following types are available and can be used to define e. g. typed helper functions:

• Direction = "prev" | "next"
• EndBehaviour = "default" | "jump”

import type { Direction, EndBehaviour } from "movenext"

// Example 1
function updateData(direction: Direction, behaviour: EndBehaviour) {
  ...
}

// Example 2
const direction: Direction | false = event.key === "ArrowDown" ? "next" : event.key === "ArrowUp" ? "prev" : false