Package org.exoplatform.agenda.util

Class CalendarFeedIcsWriter

java.lang.Object

org.exoplatform.agenda.util.CalendarFeedIcsWriter

public final class CalendarFeedIcsWriter
extends Object

Writes the iCalendar document a calendar link serves.

What it says about an event: its title, its time, its location and its description — nothing else. The document is read by whoever holds the URL, with no eXo account behind them, so nothing that names or acts for a person goes in: no ORGANIZER, no ATTENDEE, no e-mail address, no answer link, no conference or event address. The mail channel (Utils.generateIcsFile(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, org.exoplatform.agenda.constant.EventAvailability, java.util.Locale, java.time.ZoneId)) and the CalDAV copy say more because each is written for one known recipient; this one is written for nobody in particular. A private event says less still: a block of busy time titled "Busy", with its start and end and nothing else.

Recurrences arrive already expanded, one Event per occurrence inside the window, exceptions applied — that is what AgendaEventService.getEvents answers. Each occurrence is written as a VEVENT of its own, with an identifier derived from its parent and its original start, so it keeps the same UID across refreshes. Rebuilding an RRULE with its EXDATEs and RECURRENCE-IDs would be a second recurrence engine beside agenda's own; the window bounds the expansion.

The same data writes the same bytes. Nothing in the document depends on the moment it is written — DTSTAMP is the event's own last change, except for a busy block, whose stamp is the constant NO_STAMP so that it does not tell when the private event was edited — so the entity tag computed over it lets a client that refreshes an unchanged calendar get a 304.

Times are written in UTC and all-day events as dates, so no VTIMEZONE is needed and every client places an event at the same instant.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	BUSY_SUMMARY	The title a private event is published under.
static final int	MAX_DOCUMENT_CHARS	Most characters of event data one document carries.
static final Duration	REFRESH_INTERVAL	How often a client is asked to refresh.

Method Summary

Modifier and Type	Method	Description
static String	write(String calendarName, List<org.exoplatform.agenda.model.Event> events, Predicate<org.exoplatform.agenda.model.Event> isPrivate, String uidHost)	Writes the document.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

REFRESH_INTERVAL

public static final Duration REFRESH_INTERVAL

How often a client is asked to refresh. Both the RFC 7986 property and the older X-PUBLISHED-TTL that Outlook reads carry it.

MAX_DOCUMENT_CHARS

public static final int MAX_DOCUMENT_CHARS

Most characters of event data one document carries. A safety stop against a calendar of very long descriptions served to an anonymous caller; events past it are left out, earliest kept.

See Also:

• Constant Field Values

BUSY_SUMMARY

public static final String BUSY_SUMMARY

The title a private event is published under.

See Also:

• Constant Field Values

Method Details

write

public static String write(String calendarName,
 List<org.exoplatform.agenda.model.Event> events,
 Predicate<org.exoplatform.agenda.model.Event> isPrivate,
 String uidHost)

Writes the document.

Parameters:

calendarName - name the subscribing application shows for the calendar, blank for none

events - the events to publish, occurrences expanded, earliest first

isPrivate - which events are published as busy time only

uidHost - host name used to qualify event identifiers

Returns:

the iCalendar document, CRLF line endings, folded