Declarative setDate() and setToday() - feature via a patch

[ajp8164]

For anyone interested this is patch that allows the setting of a date using new functions on the CalendarProvider.

Two functions:
setDate: (date: string) => void
setToday: () => void (a convenience function)

Just create a ref on the CalendarProvider and call a function.

Using these functions I'm able to place today, left, and right arrows anywhere on my view (specifically outside the calendar component). I'm using luxon for dates.

Example:

const [current, setCurrent] = useState<ISODateString>(
  DateTime.now().toFormat('yyyy-MM-dd'),
);

...

<CalendarProvider
  ref={calRef}
  ...
/>

...

onPress={() => {
  const newDate = DateTime.fromISO(current)
    .plus({ month: 1 })
    .toISODate();
  if (newDate) {
    calRef.current?.setDate(newDate);
    setCurrent(newDate);
  }
}}

Patch:

diff --git a/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.d.ts b/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.d.ts
index 8219efa..20d1dd3 100644
--- a/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.d.ts
+++ b/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.d.ts
@@ -3,6 +3,7 @@ import { ViewStyle, ViewProps, StyleProp } from 'react-native';
 import { Theme, DateData } from '../../types';
 import { UpdateSources, CalendarNavigationTypes } from '../commons';
 export interface CalendarContextProviderProps extends ViewProps {
+    ref: RefObject<CalendarContextProviderImperativeMethods | null>;
     /** Initial date in 'yyyy-MM-dd' format. Default = now */
     date: string;
     /** Specify theme properties to override specific styles for calendar parts */
@@ -28,6 +29,10 @@ export interface CalendarContextProviderProps extends ViewProps {
     /** The left inset of the timeline calendar (sidebar width), default is 72 */
     timelineLeftInset?: number;
 }
+export interface CalendarContextProviderImperativeMethods {
+    setDate: (date: string) => void;
+    setToday: () => void;
+}; 
 /**
  * @description: Calendar context provider component
  * @example: https://github.com/wix/react-native-calendars/blob/master/example/src/screens/expandableCalendar.js
diff --git a/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.js b/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.js
index ec1e1be..f4dbc03 100644
--- a/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.js
+++ b/node_modules/react-native-calendars/src/expandableCalendar/Context/Provider.js
@@ -1,6 +1,6 @@
 import { includes } from 'lodash';
 import XDate from 'xdate';
-import React, { useRef, useState, useCallback, useMemo } from 'react';
+import React, { forwardRef, useRef, useState, useCallback, useMemo, useImperativeHandle } from 'react';
 import { View } from 'react-native';
 import { sameMonth } from '../../dateutils';
 import { xdateToData } from '../../interface';
@@ -9,11 +9,21 @@ import { UpdateSources } from '../commons';
 import styleConstructor from '../style';
 import CalendarContext from './index';
 import TodayButton from './todayButton';
+import { toMarkingFormat } from '../../interface';
 /**
  * @description: Calendar context provider component
  * @example: https://github.com/wix/react-native-calendars/blob/master/example/src/screens/expandableCalendar.js
  */
-const CalendarProvider = (props) => {
+const CalendarProvider = (props, ref) => {
+    useImperativeHandle(ref, () => ({
+        setDate: (date) => {
+            _setDate(date, UpdateSources.DAY_PRESS);
+        },
+        setToday: () => {
+            _setDate(date, UpdateSources.TODAY_PRESS);
+        }
+    }));
+
     const { theme, date, onDateChanged, onMonthChange, disableAutoDaySelection, showTodayButton = false, disabledOpacity, todayBottomMargin, todayButtonStyle, style: propsStyle, numberOfDays, timelineLeftInset = 72, children } = props;
     const style = useRef(styleConstructor(theme));
     const todayButton = useRef();
@@ -30,6 +40,10 @@ const CalendarProvider = (props) => {
             _setDate(date, UpdateSources.PROP_UPDATE);
         }
     }, [date]);
+    const getTodayDate = () => {
+        return toMarkingFormat(new XDate());
+    };
+
     const getUpdateSource = useCallback((updateSource) => {
         // NOTE: this comes to avoid breaking those how listen to the update source in onDateChanged and onMonthChange - remove on V2
         if (updateSource === UpdateSources.ARROW_PRESS || updateSource === UpdateSources.WEEK_ARROW_PRESS) {
@@ -76,5 +90,5 @@ const CalendarProvider = (props) => {
       {showTodayButton && renderTodayButton()}
     </CalendarContext.Provider>);
 };
-export default CalendarProvider;
+export default forwardRef(CalendarProvider);
 CalendarProvider.displayName = 'CalendarProvider';

Ed. this library is way out of date but seems to be the best library for the features it provides. I have many patches on my project because maintainers go missing and patching is more straightforward than forking and maintaining. This is a general comment on many RN libraries and GH capabilities. There should be a reputation based way to have any user contribute :-/