src/info.js
import { DateTime } from './datetime';
import { Settings } from './settings';
import { Locale } from './impl/locale';
import { Util } from './impl/util';
/**
* The Info class contains static methods for retrieving general time and date related data. For example, it has methods for finding out if a time zone has a DST, for listing the months in any supported locale, and for discovering which of Luxon features are available in the current environment.
*/
export class Info {
/**
* Return whether the specified zone contains a DST.
* @param {string|Zone} [zone='local'] - Zone to check. Defaults to the environment's local zone.
* @return {boolean}
*/
static hasDST(zone = Settings.defaultZone) {
return (
!zone.universal &&
DateTime.local()
.setZone(zone)
.set({ month: 1 }).offset !==
DateTime.local()
.setZone(zone)
.set({ month: 5 }).offset
);
}
/**
* Return an array of standalone month names.
* @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DateTimeFormat
* @param {string} [length='long'] - the length of the month representation, such as "numeric", "2-digit", "narrow", "short", "long"
* @param {object} opts - options
* @param {string} [opts.locale='en'] - the locale code
* @param {string} [opts.numberingSystem=null] - the numbering system
* @param {string} [opts.outputCalendar='gregory'] - the calendar
* @example Info.months()[0] //=> 'January'
* @example Info.months('short')[0] //=> 'Jan'
* @example Info.months('numeric')[0] //=> '1'
* @example Info.months('short', { locale: 'fr-CA' } )[0] //=> 'janv.'
* @example Info.months('numeric', { locale: 'ar' })[0] //=> '١'
* @example Info.months('long', { outputCalendar: 'islamic' })[0] //=> 'Rabiʻ I'
* @return {[string]}
*/
static months(
length = 'long',
{ locale = 'en', numberingSystem = null, outputCalendar = 'gregory' } = {}
) {
return new Locale(locale, numberingSystem, outputCalendar).months(length);
}
/**
* Return an array of format month names.
* Format months differ from standalone months in that they're meant to appear next to the day of the month. In some languages, that
* changes the string.
* See {@link months}
* @param {string} [length='long'] - the length of the month representation, such as "numeric", "2-digit", "narrow", "short", "long"
* @param {object} opts - options
* @param {string} [opts.locale='en'] - the locale code
* @param {string} [opts.numbering=null] - the numbering system
* @param {string} [opts.outputCalendar='gregory'] - the calendar
* @return {[string]}
*/
static monthsFormat(
length = 'long',
{ locale = 'en', numberingSystem = null, outputCalendar = 'gregory' } = {}
) {
return new Locale(locale, numberingSystem, outputCalendar).months(length, true);
}
/**
* Return an array of standalone week names.
* @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DateTimeFormat
* @param {string} [length='long'] - the length of the month representation, such as "narrow", "short", "long".
* @param {object} opts - options
* @param {string} [opts.locale='en'] - the locale code
* @param {string} [opts.numbering=null] - the numbering system
* @param {string} [opts.outputCalendar='gregory'] - the calendar
* @example Info.weekdays()[0] //=> 'Monday'
* @example Info.weekdays('short')[0] //=> 'Mon'
* @example Info.weekdays('short', 'fr-CA')[0] //=> 'lun.'
* @example Info.weekdays('short', 'ar')[0] //=> 'الاثنين'
* @return {[string]}
*/
static weekdays(length = 'long', { locale = 'en', numberingSystem = null } = {}) {
return new Locale(locale, numberingSystem, null).weekdays(length);
}
/**
* Return an array of format week names.
* Format weekdays differ from standalone weekdays in that they're meant to appear next to more date information. In some languages, that
* changes the string.
* See {@link weekdays}
* @param {string} [length='long'] - the length of the month representation, such as "narrow", "short", "long".
* @param {object} opts - options
* @param {string} [opts.locale='en'] - the locale code
* @param {string} [opts.numbering=null] - the numbering system
* @param {string} [opts.outputCalendar='gregory'] - the calendar
* @return {[string]}
*/
static weekdaysFormat(length = 'long', { locale = 'en', numberingSystem = null } = {}) {
return new Locale(locale, numberingSystem, null).weekdays(length, true);
}
/**
* Return an array of meridiems.
* @param {object} opts - options
* @param {string} [opts.locale='en'] - the locale code
* @example Info.meridiems() //=> [ 'AM', 'PM' ]
* @example Info.meridiems('de') //=> [ 'vorm.', 'nachm.' ]
* @return {[string]}
*/
static meridiems({ locale = 'en' } = {}) {
return new Locale(locale).meridiems();
}
/**
* Return an array of eras, such as ['BC', 'AD']. The locale can be specified, but the calendar system is always Gregorian.
* @param {string} [length='short'] - the length of the era representation, such as "short" or "long".
* @param {object} opts - options
* @param {string} [opts.locale='en'] - the locale code
* @example Info.eras() //=> [ 'BC', 'AD' ]
* @example Info.eras('long') //=> [ 'Before Christ', 'Anno Domini' ]
* @example Info.eras('long', 'fr') //=> [ 'avant Jésus-Christ', 'après Jésus-Christ' ]
* @return {[string]}
*/
static eras(length = 'short', { locale = 'en' } = {}) {
return new Locale(locale, null, 'gregory').eras(length);
}
/**
* Return the set of available features in this environment.
* Some features of Luxon are not available in all environments. For example, on older browsers, timezone support is not available. Use this function to figure out if that's the case.
* Keys:
* * `timezones`: whether this environment supports IANA timezones
* * `intlTokens`: whether this environment supports internationalized token-based formatting/parsing
* * `intl`: whether this environment supports general internationalization
* @example Info.feature() //=> { intl: true, intlTokens: false, timezones: true }
* @return {object}
*/
static features() {
let intl = false,
intlTokens = false,
zones = false;
if (Util.isUndefined(Intl) && Util.isUndefined(Util.DateTimeFormat)) {
intl = true;
intlTokens = Util.isUndefined(Intl.DateTimeFormat.prototype.formatToParts);
try {
Intl.DateTimeFormat({ timeZone: 'America/New_York' });
zones = true;
} catch (e) {
zones = false;
}
}
return { intl, intlTokens, zones };
}
}