add an "eventMapper" prop to calendar-google

allows editing events after they're fetched, but before they're rendered
in the list. Lets us take advantage of the new "config" property to
clean up events from certain data sources, if needed.

Author: hawkrives

source/views/calendar/calendar-google.js

@@ -13,7 +13,11 @@ import qs from 'querystring'
 import {GOOGLE_CALENDAR_API_KEY} from '../../lib/config'
 const TIMEZONE = 'America/Winnipeg'
 
-type Props = TopLevelViewPropsType & {calendarId: string, poweredBy: ?PoweredBy}
+type Props = TopLevelViewPropsType & {
+	calendarId: string,
+	eventMapper?: EventType => EventType,
+	poweredBy: ?PoweredBy,
+}
 
 type State = {
 	events: EventType[],
@@ -52,7 +56,7 @@ export class GoogleCalendarView extends React.Component<Props, State> {
 	}
 
 	convertEvents(data: GoogleEventType[], now: moment): EventType[] {
-		return data.map(event => {
+		let events = data.map(event => {
 			const startTime = moment(event.start.date || event.start.dateTime)
 			const endTime = moment(event.end.date || event.end.dateTime)
 
@@ -70,6 +74,12 @@ export class GoogleCalendarView extends React.Component<Props, State> {
 				},
 			}
 		})
+
+		if (this.props.eventMapper) {
+			events = events.map(this.props.eventMapper)
+		}
+
+		return events
 	}
 
 	getEvents = async (now: moment = moment.tz(TIMEZONE)) => {