CalendarView
is a SwiftUI wrapper of UICalendarView
, which is a view that displays a calendar that provides for user selection of a single date or multiple dates. It also allows for displaying date-specific decorations.
More info on its full capabilities can be found at Apple's documentation for UICalendarView
.
The minimum needed to work with CalendarView
is to attach it to a Binding
variable with a DateComponents
type. If you want to limit date selection to a single date at a time, use an optional DateComponents
. To allow multiple date selection, the Binding
should be a Set<DateComponents>
(a Set
of DateComponents
).
Tip
If you don't need to track any selection, you can also omit this parameter entirely.
And, alternatively, if using multiple selection and the order the selections are made matters, you can use [DateComponents]
instead of a Set
.
struct ContentView: View {
@State
private var singleDateSelection: DateComponents? = nil
@State
private var multipleDateSelection: Set<DateComponents> = []
var body: some View {
VStack {
// No selection tracking
CalendarView()
// Single date selection tracking
CalendarView($singleDateSelection)
// Multiple date selection tracking
CalendarView($multipleDateSelection)
}
}
}
Warning
When updating the selection
Binding
outside of CalendarView
, be wary.
If you manually create or make changes to a DateComponents
instance output from CalendarView
with components that aren't exactly the same as those set internally by the view, you might get unexpected behavior, such as duplicate selections and more.
It's recommended to use the Binding
as a "read-only" property and not to write to it directly.
Some elements of the CalendarView
can be set with SwiftUI Environment
and its standard ViewModifier
(environment(_:_:)
).
This also means that CalendarView
also reacts to these settings if they're set in the parent Environment
. And for convenience, the package comes with abbreviated modifiers to directly set these values.
These elements are:
- The actual calendar system (
calendar
/Calendar
)- i.e. Gregorian vs. Chinese vs. Buddhist
- The language (
locale
/Locale
) - The time zone (
timeZone
/TimeZone
)- Changing this won't have a visual effect, but the selected
DateComponent
values it outputs will have the appliedTimeZone
(or the one in the activeEnvironment
) pre-set.
- Changing this won't have a visual effect, but the selected
CalendarView($selectedDate)
// Environment Modifier
// Calendar
.environment(\.calendar, Calendar(identifier: .chinese))
// Locale
.environment(\.locale, Locale(identifier: "en_GB"))
// Time Zone
.environment(\.timeZone, TimeZone(identifier: "America/Chicago")!)
// Convenience Modifiers
// Calendar
.calendar(Calendar(identifier: .chinese))
// Locale
.locale(Locale(identifier: "en_GB"))
// Time Zone
.timeZone(TimeZone(identifier: "America/Chicago")!)
Another feature of UICalendarView
(and therefore, CalendarView
by proxy), is to display "decorations" along with any of the dates in the calendar. These can be different for different dates in the calendar, one type of decoration for all dates, or no decorations whatsoever.
The different types of decorations are as follows:
default(color: Color? = nil, size: DecorationSize = .medium)
- A decoration with a filled circle image, using the color and size you specify.
image(_ systemName: String, color: Color? = nil, size: DecorationSize = .medium)
- A decoration with the image, color, and size that you specify.
- You can specify an image with a
UIImage
or the name of an SF Symbols icon. - If you don't specify an image, it defaults to the
circlebadge.fill
symbol. - If you don't specify a color, it defaults to
systemFill
.
custom(@ViewBuilder _ customViewProvider: () -> some View)
- A custom decoration with a custom SwiftUI view, via a
@ViewBuilder
closure.
- A custom decoration with a custom SwiftUI view, via a
Tip
You can use multiple decoration modifiers to specify different decorations for different dates (or for all dates not explicitly specified in other modifiers).
A decoration for a explicitly specified for a particular date takes precedence over a decoration specified for no specific date.
CalendarView($selectedDate)
// This sets an orange `star.fill` symbol under all dates in the calendar.
.decorations(.image("star.fill", color: .orange))
// This displays the month number under each date (why not?) using a SwiftUI ViewBuilder
.decorations { dateComponents in
Text(dateComponents.month ?? 0, format: .number)
}
The font design that the calendar view uses for displaying calendar text. CalendarView
comes with a ViewModifier
to set this:
CalendarView($selectedDate)
.fontDesign(.rounded)
Using the visibleDateComponents
parameter in CalendarView
's initializer (Binding<DateComponents?>
), you can control the visible part of in the calendar view. It can also be used to keep track of what part of the calendar is currently be used.
struct ContentView: View {
@State
private var selectedDate: DateComponents? = nil
// This sets the initial month shown to May 2024
@State
private var currentlyViewedComponents: DateComponents? = .init(
calendar: calendar,
year: 2024,
month: 5
)
var body: some View {
CalendarView(
$selectedDate,
visibleDateComponents: $currentlyViewedComponents
)
}
}
Important
If visibleDateComponents
's calendar
property is set to a different Calendar
than the view's calendar
(see Environment Values), the view uses the current Environment
's calendar
, which may result in an invalid date from the date components.
Using the availableDateRange
parameter in CalendarView
's initializer (DateInterval
), you can control the range of dates that the calendar view is able to display. Setting this parameter restricts the earliest or latest dates that the calendar view displays. The default date range is from distantPast
to distantFuture
.
For convenience, an extra protocol comes with the package: DateRangeExpression
, which allows a DateInterval
to be initialized from a few of the range types. Additionally, it comes with support for using "Range
-literal" syntax with Date
values to create a DateInterval
value. Specifically, it works with the syntax for:
ClosedRange
:date1...date2
PartialRangeFrom
:date1...
- Open upper end of range is set to
distantFuture
.
- Open upper end of range is set to
PartialRangeThrough
:...date2
- Open lower end of range is set to
distantPast
.
- Open lower end of range is set to
CalendarView(
$selectedDate,
// This would only allow the user to select
// a date from the current moment in time onward.
availableDateRange: Date.now...
)