The WebDAV protocol provides a framework for users to create, change and move documents on a server. The most important features include the maintenance of properties about an author or modification date, namespace management, collections, and overwrite protection. Maintenance of properties includes such things as the creation, removal, and querying of file information. Namespace management deals with the ability to copy and move web pages within a server's namespace. Collections deal with the creation, removal, and listing of various resources. Lastly, overwrite protection handles aspects related to the locking of files. It takes advantage of existing technologies such as Transport Layer Security, digest access authentication or XML to satisfy those requirements.[3]
The meetings resulted in the formation of an IETF working group because the new effort would lead to extensions to HTTP, which the IETF had started to standardize.
As work began on the protocol, it became clear that handling both distributed authoring and versioning together would involve too much work and that the tasks would have to be separated. The WebDAV group focused on distributed authoring, and left versioning for the future. (The Delta-V extension added versioning later – see the Extensions section below.)
The WebDAV working group concluded its work in March 2007, after the Internet Engineering Steering Group (IESG) accepted an incremental update to RFC2518. Other extensions left unfinished at that time, such as the BIND method, have been finished by their individual authors, independent of the formal working group.[8]
retrieve properties, stored as XML, from a web resource. It is also overloaded to allow one to retrieve the collection structure (also known as directory hierarchy) of a remote system.
PROPPATCH
change and delete multiple properties on a resource in a single atomic act
UNLOCK
remove a lock from a resource
Properties
The properties of WebDAV protocol are name–value pair, in which a "name" is a Uniform Resource Identifier (URI) and the "values" are expressed through XML elements. Furthermore, the methods to handle the properties are PROPFIND and PROPPATCH.[9]
Documents produced by the working group
The WebDAV working group produced several works:
a requirements document: "Requirements for a Distributed Authoring and Versioning Protocol for the World Wide Web" RFC2291, issued February 1998
a base protocol document (excluding versioning, despite its title): "HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV)" RFC4918, issued June 2007 (which updates and supersedes "HTTP Extensions for Distributed Authoring – WebDAV" RFC2518, issued February 1999)
the ordered collections protocol: "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol" RFC3648, issued December 2003
the access control protocol: "Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol" RFC3744, issued May 2004
a quota specification: "Quota and Size Properties for Distributed Authoring and Versioning (DAV) Collections" RFC4331, issued February 2006
a redirect specification: "Web Distributed Authoring and Versioning (WebDAV) Redirect Reference Resources" RFC4437, issued March 2006
Other documents published through IETF
the versioning protocol: "Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning)" RFC3253 (created by the Delta-V working group)
a specification of WebDAV property datatypes: "Datatypes for Web Distributed Authoring and Versioning (WebDAV) Properties" RFC4316
a document defining how to initiate mounting of a WebDAV resource: "Mounting Web Distributed Authoring and Versioning (WebDAV) Servers" RFC4709
a calendar access protocol: "Calendaring Extensions to WebDAV (CalDAV)" RFC4791
a query protocol: "Web Distributed Authoring and Versioning (WebDAV) SEARCH" RFC5323
an extension to the WebDAV ACL specification: "WebDAV Current Principal Extension" RFC5397
an extension to the WebDAV MKCOL method: "Extended MKCOL for Web Distributed Authoring and Versioning (WebDAV)" RFC5689
an extension of the collection model, defining creation and discovery of additional bindings to a resource: "Binding Extensions to Web Distributed Authoring and Versioning (WebDAV)" RFC5842
an application of POST to WebDAV collections: "Using POST to Add Members to Web Distributed Authoring and Versioning (WebDAV) Collections" RFC5995
an extension which allows synchronizing large collections efficiently: "Collection Synchronization for Web Distributed Authoring and Versioning (WebDAV)" RFC6578
Extensions and derivatives
For versioning, the Delta-V protocol under the Web Versioning and Configuration Management working group adds resource revision tracking, published in RFC3253.
For searching and locating, the DAV Searching and Locating (DASL) working group never produced any official standard although there are a number of implementations of its last draft. Work continued as non-working-group activity.[10] The WebDAV Search specification attempts to pick up where the working group left off, and was published as RFC5323 in November 2008.[11]
For calendaring, CalDAV is a protocol allowing calendar access via WebDAV. CalDAV models calendar events as HTTP resources in iCalendar format, and models calendars containing events as WebDAV collections.
For groupware, GroupDAV is a variant of WebDAV which allows client/server groupware systems to store and fetch objects such as calendar items and address book entries instead of web pages.
For MS Exchange interoperability, WebDAV can be used for reading/updating/deleting items in a mailbox or public folder. WebDAV for Exchange has been extended by Microsoft to accommodate working with messaging data. Exchange Server version 2000, 2003, and 2007 support WebDAV. However, WebDAV support has been discontinued in Exchange 2010[12] in favor of Exchange Web Services (EWS), a SOAP/XML based API.
As part of the Windows Server Protocols (WSPP) documentation set,[13] Microsoft published the following protocol documents detailing extensions to WebDAV:
[MS-WDVME]: Web Distributed Authoring and Versioning (WebDAV) Protocol: Microsoft Extensions.[14] These extensions include a new verb and new headers, and properties that enable previously unmanageable file types and optimize protocol interactions for file system clients. These extensions introduce new functionality into WebDAV, optimize processing, and eliminate the need for special-case processing.
[MS-WDV]: Web Distributed Authoring and Versioning (WebDAV) Protocol: Client Extensions.[15] The client extensions in this specification extend the WebDAV Protocol by introducing new headers that both enable the file types that are not currently manageable and optimize protocol interactions for file system clients. These extensions do not introduce new functionality into the WebDAV Protocol, but instead optimize processing and eliminate the need for special-case processing.
[MS-WDVSE]: Web Distributed Authoring and Versioning (WebDAV) Protocol: Server Extensions.[16] The server extensions in this specification extend WebDAV by introducing new HTTP request and response headers that both enable the file types that are not currently manageable and optimize protocol interactions for file system clients. This specification also introduces a new WebDAV method that is used to send search queries to disparate search providers.
[MS-WEBDAVE]: Web Distributed Authoring and Versioning Error Extensions Protocol Specification.[17] This SharePoint Front-End Protocol describes extended error codes and extended error handling mechanism specified in [MS-WDV] to enable compliant servers to report error condition details on a server response.
File Transfer Protocol (FTP), a simple and widely adopted network protocol based on IP, allows users to transfer files between network hosts. FTPS extends FTP for secure traffic.
SSH File Transfer Protocol (SFTP), an extension of the Secure Shell protocol (SSH) version 2.0, provides secure file-transfer capability; and scp, a form of SFTP that runs as a single command similar to a regular cp (copy) command in the shell.
Rsync, a protocol and a command similar to scp, that can also skip rewriting identical files and portions of files, or skip newer files, etc.
AtomPub, an HTTP-based protocol for creating and updating web resources, can be used for some of the use cases of WebDAV. It is based on standard HTTP verbs with standardized collection resources that behave somewhat like the WebDAV model of directories.
CMIS, a standard consisting of a set of Web services for sharing information among disparate content repositories, seeks to ensure interoperability for people and applications using multiple content repositories; it has both SOAP- and AtomPub-based interfaces
Linked Data Platform (LDP), a Linked Data specification defining a set of integration patterns for building RESTful HTTP services that are capable of read-write of RDF data.
