@onsetsoftware/headless-calendar
v0.6.0
Published
A simple and easy to use JavaScript library that provides common calendar functionalities for making completely customizable calendar UI. Based heavily on the work done by [https://github.com/ashutoshbw/headless-calendar](https://github.com/ashutoshbw/hea
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Headless Calendar
A simple and easy to use JavaScript library that provides common calendar functionalities for making completely customizable calendar UI. Based heavily on the work done by https://github.com/ashutoshbw/headless-calendar
💡 Features
- It does all the calculations for finding the position of a day in a calendar.
- A calendar is an iterable. So you can use
for of
loop or the spread syntax to easily iterate over the days. - You can choose which day to start a week with.
- Provides handy calendar classes for generating calendar of any month, year, last year or any period of time supported by original JavaScript Date object.
- It is based on original JavaScript
Date
but provides an abstraction over by excluding all the parts that doesn't needed or are not intuitive.
Installation
N/A for now
Meet the tools
Classes | Description
--- | ---
Calendar
| It is the generic class for generating any arbitrary calendar from any date to any future date.
CalendarOfMonth
| It generates calendar of any given month.
CalendarOfYear
| It generates calendar of any given year.
PlainDate
| It is a simple wrapper around the JavaScript Date
. You can use it to find the difference between two dates, next, previous days and some other helpful things.
You can fetch the above classes using both ES6 and CommonJS module syntax.
🦉 Concepts
To understand how to use headless-calendar
effectively, it will be helpful to picture a calendar as a two dimensional diagram like below:
+-------------------------> Day Axis
| 0 1 2 3 4 5 6 ---> Day Axis indices. Starts with 0.
| V V V V V V V
| Su Mo Tu We Th Fr Sa ---> Day Names
| 1 2 3 4 ---> 0
| 5 6 7 8 9 10 11 ---> 1
| 12 13 14 15 16 17 18 ---> 2
| 19 20 21 22 23 24 25 ---> 3
| 26 27 28 29 30 31 ---> 4
| |
V V
Week Axis Week Axis indices. Starts with 0 too.
Examples
import {CalendarOfMonth} from "@onsetsoftware/headless-calendar";
// generates the calendar of January of 2021
const month = new CalendarOfMonth(2021, 1);
for (day of month) {
console.log(day);
}
/*
Day {
date: PlainDate { year: 2021, month: 1, date: 1 },
dayNumber: 1, // it counts the day
dayOfTheWeek: 1, // the day of the week from 0-6 = Sun - Sat
dayAxisIndex: 5, // the day axis index as explained in the above diagram
weekAxisIndex: 0 // the week axis index as explained in the above diagram
}
.
.
.
*/
The day object holds the necessary information about it's position on the calendar. This pattern of accessing days are same for all the calendar classes.
And as any calendar is an iterable you can also use it like below:
// console logs only dates that are Sundays
[...month].forEach(day => {
if (day.dayAxisIndex == 0) {
console.log(day.date.date);
}
})
Calendar
This class is used to generate a calendar starting with any date to any future date. All the other calendar classes are derived from it.
Syntax:
new Calendar(startDateString, endDateString, [startWeekDayIndex])
Parameters
startDateString
(String) andendDateString
(String): They should follow the formatyear-month-date
format. Each part is expressed with digits.endDateString
must represent a equal or later date thanstartDateString
.startWeekDayIndex
(Number) Optional: It represents the day to start the week with.0
means Sunday and it goes on incrementally until 6 means Saturday.
Return value
An iterable object. It has the following properties:
startDate
: It is thePlainDate
version of starting date.endDate
: It is thePlainDate
version of ending date.startWeekDayIndex
: It keeps record of thestartWeekDayIndex
parameters value. It that is not provided it defaults to zero.maxWeekAxisIndex
: This returns last week's week axis index.weekDayNames
: It returns an array of day names with the starting day as you specified with thestartWeekDayIndex
parameter.length
: It returns the number total days in the calendar.
And it has a toString()
method for easily seeing the output of a calendar. For example:
import {Calendar} from "@onsetsoftware/headless-calendar";
const cal = new Calendar("2021-1-1", "2021-2-10");
console.log(cal.toString());
/*
Su Mo Tu We Th Fr Sa
1 2 January 2021
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31 1 2 3 4 5 6 February
7 8 9 10
*/
The iterable is used to iterate over the days of the calendar. Each item of the sequence of this iterable is an object that represents a day. These day objects comes with the following properties and methods:
Properties
date
: APlainDate
representing that day.dayNumber
: If it is n, it means it's the nth day of the calendar.dayOfTheWeek
: the number 0-6 indicating Sunday (0) - Saturday (6).dayAxisIndex
: It is the day axis index of the day as shown in diagram.weekAxisIndex
: It is the week axis index of the day as shown in diagram.
Methods
isFirstDayOfWeekAndMonth()
: It returns a Boolean value indicating if the day is the 1st day of the week and also the 1st day of the month. This value is useful if you want to show month names right above such days.
CalendarOfMonth
This class is used to generate a calendar of the specified month.
Syntax:
new CalendarOfMonth(year, month, [startWeekDayIndex])
Parameters
year
(Number) andmonth
(Number): The year and month number for generating the calendar. Note that unlike in JavaScript, here month starts with1
(January).startWeekDayIndex
(Number) Optional: It represents the day to start the week with.0
means Sunday and it goes on incrementally until 6 means Saturday.
Return value
An iterable object with the same interface of a Calendar
instance representing the days of the specified month.
It's toString()
method formats the calendar a little differently than the original Calendar
class:
import {CalendarOfMonth} from "@onsetsoftware/headless-calendar";
const month = new CalendarOfMonth(2021, 1);
console.log(month.toString())
/*
January 2021
Su Mo Tu We Th Fr Sa
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
*/
CalendarOfYear
This class is used to generate a calendar of the given year.
Syntax:
new CalendarOfYear(year, [startWeekDayIndex])
Parameters
year
(Number): The year number for generating the calendar.startWeekDayIndex
(Number) Optional: It represents the day to start the week with.0
means Sunday and it goes on incrementally until 6 means Saturday.
Return value
An iterable object with the same interface of a Calendar
instance, representing the days of the specified year.
PlainDate
PlainDate
is wrapper class around the original JavaScript Date
. It only thinks about year, month and date. No hours, minutes or others parts.
Syntax:
new PlainDate(dateString: DateString, locale?: Intl.LocalesArgument)
Parameters
dateString
(String) Optional: It should follow the formatyear-month-date
format. Each part is expressed with digits. If it is omitted, it is treated as current date according to local time.
Return value
An instance of PlainDate
. It it only has three properties year
, month
and date
holding the corresponding given information.
A PlainDate
instance has the following methods:
toJSDate
It converts a PlainDate
to JavaScript date.
Syntax:
somePlainDate.toJSDate()
Parameters
No parameter
Return value
JavaScript version of the PlainDate
.
equals
Checks whether two PlainDate
s are equal or not.
Syntax:
somePlainDate.equals(another)
Parameters
another
(PlainDate): AnotherPlainDate
value to compare to.
Return value
A Boolean value indicating whether the PlainDate
equals another
PlainDate
.
isBefore
Checks whether the given PlainDate
is before the current one.
Syntax:
somePlainDate.isBefore(another)
Parameters
another
(PlainDate): AnotherPlainDate
value to compare to.
Return value
A Boolean value indicating whether the PlainDate
is before another
PlainDate
.
isAfter
Checks whether the given PlainDate
is after the current one.
Syntax:
somePlainDate.isBefore(another)
Parameters
another
(PlainDate): AnotherPlainDate
value to compare to.
Return value
A Boolean value indicating whether the PlainDate
is after another
PlainDate
.
diff
Returns the difference between two PlainDate
s.
Syntax:
somePlainDate.diff(another);
Parameters
another
(PlainDate): AnotherPlainDate
value to find the difference.
Return value
The difference between the two PlainDate
s. Note that the boundary dates are included in the counting.
next
Returns the next PlainDate
.
Syntax:
somePlainDate.next();
Parameters
None.
Return value
The next PlainDate
.
previous
Returns the previous PlainDate
.
Syntax:
somePlainDate.previous();
Parameters
None.
Return value
The previous PlainDate
.
addDays
Returns the day days
after the active PlainDate
.
Syntax:
somePlainDate.addDays(days);
Parameters
days
(number): The number of days to add
Return value
The PlainDate
days
after the active date.
subDays
Returns the day days
before the active PlainDate
.
Syntax:
somePlainDate.subDays(days);
Parameters
days
(number): The number of days to subtract
Return value
The PlainDate
days
before the active date.
toString
A string representation of the PlainDate
as a DateString
.
Syntax:
somePlainDate.toString();
Parameters
None.
Return value
A string representation of somePlainDate
with the year-month-date
format where each part is made of digits. year
is full year.
Static methods of PlainDate
fromJSDate
Returns a plain date from a JavaScript date.
Syntax:
PlainDate.fromJSDate(date, [UTC])
Parameters
date
(Date): A JavaScriptDate
instance.UTC
(Boolean) Optional: By default it istrue
, that means the date is treated as UTC time. If you want local time, set it tofalse
.
Return value
The PlainDate
version of the JavaScript date according to UTC or local time(based on the 2nd parameter).
today
Returns today in PlainDate
.
Syntax:
PlainDate.today([UTC])
Parameters
UTC
(Boolean) Optional: By default it istrue
, that means we will get result in UTC time. If you want local time set it tofalse
.
Return value
Today in PlainDate
according local time or UTC time(based on the 1st parameter).
License
MIT