Package org.exoplatform.agenda.util

Class CalendarFeedParser

java.lang.Object

org.exoplatform.agenda.util.CalendarFeedParser

public final class CalendarFeedParser
extends Object

Reads an iCalendar document into the occurrences a subscription imports (EXO-90278).

Occurrences, not series. A recurring event is expanded by ical4j — RRULE, RDATE and EXDATE, in the event's own time zone, daylight saving included — within the window, and each instance a RECURRENCE-ID override replaces is taken from the override. Agenda's recurrence model cannot hold every rule a feed may carry, and an expansion is one truthful path for all of them. Every occurrence is identified by its UID and the instant it was originally scheduled at, so a refresh finds the same occurrence again.

What is kept: title, location and description as plain text, the times, whether the event is all-day, and its transparency. A cancelled event or instance is left out. Organizers, attendees, alarms, attachments and URLs are never read.

Bounds: rules repeating by the second or the minute are not expanded, the expansion stops once it has produced four times the number of occurrences kept, and only the earliest maxEvents occurrences are kept.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	CalendarFeedParser.ImportedEvent	One occurrence, ready to be written as an agenda event.
static final record	CalendarFeedParser.ParsedCalendar	A document read.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_DESCRIPTION	Longest description kept, in characters of plain text.
static final int	MAX_NAME	Longest calendar name kept.
static final int	MAX_TEXT	Longest title or location kept.

Method Summary

Modifier and Type	Method	Description
static String	descriptionMarkup(String text)	Turns a plain-text description into the markup agenda renders a description with: escaped, line breaks kept.
static CalendarFeedParser.ParsedCalendar	parse(byte[] body, Instant windowStart, Instant windowEnd, int maxEvents)	Reads a document.

Methods inherited from class java.lang.Object

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

Field Details

MAX_TEXT

public static final int MAX_TEXT

Longest title or location kept.

See Also:

• Constant Field Values

MAX_DESCRIPTION

public static final int MAX_DESCRIPTION

Longest description kept, in characters of plain text.

See Also:

• Constant Field Values

MAX_NAME

public static final int MAX_NAME

Longest calendar name kept.

See Also:

• Constant Field Values

Method Details

parse

public static CalendarFeedParser.ParsedCalendar parse(byte[] body,
 Instant windowStart,
 Instant windowEnd,
 int maxEvents)
                                               throws CalendarFeedException

Reads a document.

Parameters:

body - the bytes read, UTF-8

windowStart - occurrences ending at or before this instant are left out

windowEnd - occurrences starting at or after this instant are left out

maxEvents - most occurrences kept

Returns:

the document read

Throws:

CalendarFeedException - when the body is not an iCalendar document, or cannot be read as one

descriptionMarkup

public static String descriptionMarkup(String text)

Turns a plain-text description into the markup agenda renders a description with: escaped, line breaks kept.

Parameters:

text - plain text, may be null

Returns:

the markup, null for no text