WebDAV

What is WebDAV?

WebDAV is Web-based Distributed Authoring and Versioning, an extension to the HTTP protocol to allow for remotely managing content on a webserver. Though the HTTP protocol does define GET, PUT, and DELETE methods, these are not sufficient for proper remote authoring (for instance, HTTP provides no method for creating a remote directory).

These extensions are general enough to use a webserver as repository for remote folders: Microsoft's "Web Folders" extension to Windows Explorer implemented this in a way that allowed for mostly-native access to a remote web repository as if it were a local folder right from the Windows desktop.

WebDAV is commonly used by web authoring systems, such as Adobe's Dreamweaver or Microsoft's Expression Web (followon to Frontpage), to publish information to the webserver.

It performs mostly the same functions that FTP does for publishing content, though a bit more efficiently and with features more in line with web publishing than FTP. FTP has always been a somewhat problematic protocol with respect to firewalls, and WebDAV has none of those issues (though WebDAV is reported to have its own issues with proxies).

WebDAV extends, not replaces the existing HTTP protocols, and a WebDAV-enabled server simply responds to a larger command set. This is best illustrated with this table showing the method names for the base HTTP protocol, WebDAV Extensions, and additional extensions supported by Microsoft.

Note that it's not necessary to understand the particulars here, but we feel that putting a new technology in context makes it easier to see where it fits in the big picture: consider it FYI-only.

 

 

protocol	method	description
HTTP	GET	Retrieves a resource (such as a web page) from the server, possible with a small amount of parameter data in the form of a query. This is the most common HTTP method.
	POST	Retrieves a resource with a possibly large number of submitted parameters. This is commonly used by a web browser.
	HEAD	Identical to a GET request, but returns just the HTTP headers and not the body of the message.
	DELETE	Attempts to delete a resources; not commonly used by a browser
	PUT	Uploads a version of a document; not commonly used by browsers.
	OPTIONS TRACE CONNECT	Not commonly used.
WebDAV	PROPFIND	Used to retrieve properties, stored as XML, from a resource. It is also overloaded to allow one to retrieve the collection structure (a.k.a. directory hierarchy) of a remote system.
	PROPPATCH	Used to change or delete ("patch") multiple properties on a resource in a single atomic act.
	MKCOL	Used to create collections (example: a directory).
	COPY	Used to copy a resource from one URI to another.
	MOVE	Used to move a resource from one URI to another.
	LOCK	Used to put a lock on a resource. WebDAV supports both shared and exclusive locks.
	UNLOCK	To remove a lock from a resource.
WebDAV w/ Microsoft Extensions	BCOPY	Batched version of COPY
	BDELETE	Batched version of DELETE
	BMOVE	Batched version of MOVE
	BPROPFIND	Batched version of PROPFIND
	BPROPPATCH	Batched version of PROPPATCH