Fix: Include extendedProps in iCalendar Events to Allow Custom Properties

[STHyeon]

Description of Changes

This pull request addresses an issue in FullCalendar when handling iCalendar feeds. According to the official FullCalendar documentation, non-standard fields in event objects are moved into the extendedProps hash during event parsing, allowing developers to add custom properties to events. However, in the current implementation for iCalendar feeds, it was not possible to include additional custom properties in extendedProps. Only specific values such as location, organizer, and description were allowed, preventing developers from adding their own custom properties.

To resolve this, I modified the expandICalEvents and buildNonDateProps functions so that any extendedProps passed as part of the event source configuration are merged into the event object. This allows custom properties provided via extendedProps to be included in the event object for iCalendar feeds.

Summary of Changes

• Updated expandICalEvents to pass the extendedProps received from the event source configuration when building each event object.
• Modified buildNonDateProps to ensure that the extendedProps are properly merged with the iCalendar event’s location, organizer, and description fields, so custom properties can be added to the event.

This fix ensures that developers can now include their own custom properties in extendedProps when working with iCalendar feeds, as described in the FullCalendar documentation.

#7761

[acerix]

Please submit this ticket under Issues describing this feature, then link this PR to it.

[STHyeon]

I added an issue! #7761