select option (es6).js

// based on https://github.com/dontwork/mithril-select/blob/master/src/components/selectOption.js

import * as m from 'mithril'
import * as isSelected from '../functions/isSelected'

const action = (option, selection, e) => {
  if (isSelected(option, selection)) {
    const i = selection.indexOf(option)
    selection.splice(i, 1)
  } else {
    Array.isArray(selection)
      ? selection.push(option)
      : selection(option)
  }
  
  e.stopPropagation()
  m.redraw()
}

const selectClass = (option, selection) => 
  isSelected(option, selection) ? 'selected' : ''
  
const highlightClass = (highlighted, index) =>
  highlighted() === index ? 'highlighted' : ''
  
const displayAttr = (search, option) => 
  search() && option.toLowerCase().indexOf(search().toLowerCase()) === -1 ? 'none' : 'block'

export const view = ({}, {
  option,
  selection,
  highlighted,
  index,
  search
}) => m('.item[tabindex=0]', {
  class: `${selectClass(option, selection)} ${highlightClass(highlighted, index)}`,
  style: {
    display: displayAttr(search, option)
  },
  onclick: e => action(option, selection, e),
  onfocus: () => highlighted(index)
  onmouseover: () => highlighted(index)
}, option)