Webcal
Encyclopedia
webcal is an unofficial Uniform Resource Identifier scheme
for accessing iCalendar
files. It is also the name of two web calendar applications written in Perl
.
Webcal was initiated for use with the Apple iCal
application and has become a common de facto
standard for accessing iCalendar
formatted files via WebDAV
. It is not an official URI scheme, such as http and ftp, as registered with IANA
. The Webcal protocol prefix is used to trigger an external protocol handler which is passed the URL
of the .ics file rather than being passed the downloaded contents of the file, in much the same way feed is sometimes used to trigger external RSS
readers. The idea is that with this protocol prefix the target file should be subscribed to rather than imported into the calendar application as would happen with a simple download.
CalDAV
and GroupDAV
are both efforts to provide WebDAV-based access to calendar stores with finer granularity. However, neither of those protocols call for using dav style URIs. Instead, both drafts call for using the HTTP OPTIONS feature to return that the server supports calendaring extensions.
URI scheme
In the field of computer networking, a URI scheme is the top level of the Uniform Resource Identifier naming structure. All URIs and absolute URI references are formed with a scheme name, followed by a colon character , and the remainder of the URI called the scheme-specific part...
for accessing iCalendar
ICalendar
iCalendar is a computer file format which allows Internet users to send meeting requests and tasks to other Internet users, via email, or sharing files with an extension of .ics...
files. It is also the name of two web calendar applications written in Perl
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...
.
Webcal was initiated for use with the Apple iCal
ICal
iCal is a personal calendar application made by Apple Inc. that runs on the Mac OS X operating system. iCal was the first calendar application for Mac OS X to offer support for multiple calendars and the ability to publish/subscribe calendars to WebDAV server....
application and has become a common de facto
De facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...
standard for accessing iCalendar
ICalendar
iCalendar is a computer file format which allows Internet users to send meeting requests and tasks to other Internet users, via email, or sharing files with an extension of .ics...
formatted files via WebDAV
WebDAV
Web-based Distributed Authoring and Versioning is a set of methods based on the Hypertext Transfer Protocol that facilitates collaboration between users in editing and managing documents and files stored on World Wide Web servers...
. It is not an official URI scheme, such as http and ftp, as registered with IANA
Internet Assigned Numbers Authority
The Internet Assigned Numbers Authority is the entity that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System , media types, and other Internet Protocol-related symbols and numbers...
. The Webcal protocol prefix is used to trigger an external protocol handler which is passed the URL
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
of the .ics file rather than being passed the downloaded contents of the file, in much the same way feed is sometimes used to trigger external RSS
RSS
-Mathematics:* Root-sum-square, the square root of the sum of the squares of the elements of a data set* Residual sum of squares in statistics-Technology:* RSS , "Really Simple Syndication" or "Rich Site Summary", a family of web feed formats...
readers. The idea is that with this protocol prefix the target file should be subscribed to rather than imported into the calendar application as would happen with a simple download.
CalDAV
CalDAV
Calendaring Extensions to WebDAV, or CalDAV, is an Internet standard allowing a client to access scheduling information on a remote server. It extends WebDAV specification and uses iCalendar format for the data. The protocol is defined by RFC 4791...
and GroupDAV
GroupDAV
GroupDAV is a computer protocol used to connect Open Source groupware clients with Open Source groupware servers. It is a lightweight protocol whose primary design goal is to be as simple as possible to implement, focusing more on real world issues with open source applications than on an...
are both efforts to provide WebDAV-based access to calendar stores with finer granularity. However, neither of those protocols call for using dav style URIs. Instead, both drafts call for using the HTTP OPTIONS feature to return that the server supports calendaring extensions.
External links
- CalDAV home page
- RFC 4324: Calendar Access Protocol
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar) (replaces RFC 2445)
- webcal description and rationale [page archived at the Wayback Machine]