lion/packages/calendar

Calendar

lion-calendar is a reusable and accessible calendar view.

import { html, css } from '@lion/core';
import './lion-calendar.js';

export default {
  title: 'Others/Calendar',
};

const calendarDemoStyle = css`
  .demo-calendar {
    border: 1px solid #adadad;
    box-shadow: 0 0 16px #ccc;
    max-width: 500px;
  }
`;

export const main = () => {
  return html`
    <style>
      ${calendarDemoStyle}
    </style>
    <lion-calendar class="demo-calendar"></lion-calendar>
  `;
};

Features

• fully accessible keyboard navigation (Arrow Keys, PgUp, PgDn, ALT+PgUp, ALT+PgDn)
• minDate: disables all dates before a given date
• maxDate: disables all dates after a given date
• disableDates: disables some dates within an available range
• selectedDate: currently selected date
• centralDate: date that determines the currently visible month and that will be focused when keyboard moves the focus to the month grid
• focusedDate: (getter only) currently focused date (if there is any with real focus)
• focusDate(date): focus on a certain date
• focusSelectedDate(): focus on the current selected date
• focusCentralDate(): focus on the current central date
• firstDayOfWeek: typically Sunday (default) or Monday
• weekdayHeaderNotation: long/short/narrow for the current locale (e.g. Thursday/Thu/T)
• locale: different locale for the current component only

How to use

Installation

npm i --save @lion/calendar

import '@lion/calendar/lion-calendar.js';

Example

<lion-calendar></lion-calendar>

Move to the selected date

The selectedDate is the date which is currently marked as selected. You usually select a date by clicking on it with the mouse or hitting Enter on the keyboard.

The selectedDate might not be within the dates in the current month view.

export const selectedDate = () => html`
  <style>
    ${calendarDemoStyle}
  </style>
  <lion-calendar class="demo-calendar" .selectedDate=${new Date(1988, 2, 5)}></lion-calendar>
`;

Central Date

The centralDate defines which day will be focused when keyboard moves the focus to the current month grid. By default it is set to today, or the enabled day of the current month view that is closest to today's date.

The next and previous months' buttons work by changing the centralDate with plus or minus one month. Changing the centralDate may mean a different view will be displayed to your users if it is in a different month. Usually if you change only the day, "nothing" happens as it's already currently in view.

The centralDate can be different from selectedDate as you can have today as actively selected but still look at date that is years ago. When the selectedDate changes, it will sync its value to the centralDate.

export const centralDate = () => {
  const today = new Date();
  const centralDate = new Date(today.getFullYear(), today.getMonth() + 1, today.getDate());
  return html`
    <style>
      ${calendarDemoStyle}
    </style>
    <lion-calendar class="demo-calendar" .centralDate="${centralDate}"></lion-calendar>
  `;
};

Controlling focus

You can control the focus by calling the following methods

• focusCentralDate()
• focusSelectedDate()
• focusDate(dateInstanceToFocus)

Be aware that the central date changes when a new date is focused.

export const controllingFocus = () => {
  const today = new Date();
  const selectedDate = new Date(today.getFullYear(), today.getMonth(), today.getDate() + 1);
  const centralDate = new Date(today.getFullYear(), today.getMonth() + 1, today.getDate());
  return html`
    <style>
      ${calendarDemoStyle}
    </style>
    <lion-calendar
      id="js-demo-calendar"
      class="demo-calendar"
      .selectedDate="${selectedDate}"
      .centralDate="${centralDate}"
    ></lion-calendar>
    <p>
      Focus
      <button @click="${() => document.querySelector('#js-demo-calendar').focusCentralDate()}">
        Central date
      </button>
      <button @click="${() => document.querySelector('#js-demo-calendar').focusSelectedDate()}">
        Selected date
      </button>
      <button @click="${() => document.querySelector('#js-demo-calendar').focusDate(today)}">
        Today
      </button>
    </p>
  `;
};

Limiting selectable values

Providing a lower limit

To give a lower limit you can bind a date to the minDate property.

export const providingLowerLimit = () => {
  const minDate = new Date();
  return html`
    <style>
      ${calendarDemoStyle}
    </style>
    <lion-calendar class="demo-calendar" .minDate="${minDate}"></lion-calendar>
  `;
};

Provide a higher limit

To give a higher limit you can bind a date to the maxDate property. In this example, we show how to create an offset of + 2 days.

export const providingHigherLimit = () => {
  const today = new Date();
  const maxDate = new Date(today.getFullYear(), today.getMonth(), today.getDate() + 2);
  return html`
    <style>
      ${calendarDemoStyle}
    </style>
    <lion-calendar class="demo-calendar" .maxDate="${maxDate}"></lion-calendar>
  `;
};

Provide a list of disabled dates

In some cases a specific date or day of the week needs to be disabled, supply those days to the disableDates property.

export const disabledDates = () => html`
  <style>
    ${calendarDemoStyle}
  </style>
  <lion-calendar
    class="demo-calendar"
    .disableDates=${day => day.getDay() === 6 || day.getDay() === 0}
  ></lion-calendar>
`;

Combined disable dates

To limit the scope of possible dates further, combine the methods mentioned above.

export const combinedDisabledDates = () => {
  const today = new Date();
  const maxDate = new Date(today.getFullYear(), today.getMonth() + 2, today.getDate());
  return html`
    <style>
      ${calendarDemoStyle}
    </style>
    <lion-calendar
      class="demo-calendar"
      .disableDates=${day => day.getDay() === 6 || day.getDay() === 0}
      .minDate="${new Date()}"
      .maxDate="${maxDate}"
    ></lion-calendar>
  `;
};