give Calendar to ViewPropsTransformer, expose a thing

src/CalendarComponent.ts

@@ -195,7 +195,7 @@ export default class CalendarComponent extends Component<CalendarComponentProps>
     for (let transformer of transformers) {
       Object.assign(
         viewProps,
-        transformer.transform(viewProps, viewSpec, props)
+        transformer.transform(viewProps, viewSpec, props, this.calendar)
       )
     }
 

src/exports.ts

@@ -43,7 +43,7 @@ export {
   intersectRects
 } from './util/geom'
 
-export { assignTo, isPropsEqual, mapHash } from './util/object'
+export { assignTo, isPropsEqual, mapHash, filterHash } from './util/object'
 
 export {
   findElements,
@@ -81,7 +81,7 @@ export {
 export { unpromisify } from './util/promise'
 
 export { default as EmitterMixin, EmitterInterface } from './common/EmitterMixin'
-export { DateRange, rangeContainsMarker, intersectRanges, rangesEqual } from './datelib/date-range'
+export { DateRange, rangeContainsMarker, intersectRanges, rangesEqual, rangesIntersect } from './datelib/date-range'
 export { defineThemeSystem } from './theme/ThemeRegistry'
 export { default as Mixin } from './common/Mixin'
 export { default as PositionCache } from './common/PositionCache'

src/plugin-system.ts

@@ -12,6 +12,7 @@ import { CalendarComponentProps } from './CalendarComponent'
 import { isPropsValidTester } from './validation'
 import { ExternalDefTransform } from './interactions-external/ExternalElementDragging'
 import { EventResizeJoinTransforms } from './interactions/EventResizing'
+import Calendar from './Calendar'
 
 // TODO: easier way to add new hooks? need to update a million things
 
@@ -56,7 +57,7 @@ export interface PluginDef extends PluginHooks {
 export type ViewPropsTransformerClass = new() => ViewPropsTransformer
 
 export interface ViewPropsTransformer {
-  transform(viewProps: ViewProps, viewSpec: ViewSpec, calendarProps: CalendarComponentProps): any
+  transform(viewProps: ViewProps, viewSpec: ViewSpec, calendarProps: CalendarComponentProps, calendar: Calendar): any
 }