Web-based Distributed Authoring and
Versioning (WebDAV) is a new Internet specification that extends the HTTP
Until now, the web has been mostly a read-only environment. We read pages off of the web, and occassionally sign a guest book or add a book review to somebody else's web site. While that has been enormously useful, two things have emerged:
- Until now, adding new pages on the web has been more complicated than it needs to be. Generally, people who don't have direct access to a server have had to understand FTP to get new pages on to the web. Many people have been able to figure out FTP, but many more have not. What's more, FTP is not a very well-controlled environment, and as a result, there are many organizations that aren't comfortable offering FTP access to their servers.
- People are looking at the Internet to supplement or replace private networks, such as LANs. People want easier ways to work from home (telecommute), or to cooperate with someone on the other side of the country, or to send data to a supplier. Thus people need to be able to share files and other resources over the Internet the same way they share files and resources on networked file systems.
Fortunately, WebDAV is a common answer to both problems.
More Technical Information
Before WebDAV, the HTTP protocol supported seven methods:
- GET (to get a page or other resource from a server);
- POST (to post data -- generally from an HTML form -- to the server);
- PUT (to put a resource onto the server);
- DELETE (to delete a resource from the server);
- OPTIONS (to find out which actions were support for a particular URL);
- TRACE; and
The most commonly used methods, today, are GET and POST.
WebDAV 1.0 adds seven additional methods to the HTTP protocol:
- MOVE (to move a resource from one URL to another)
- COPY (to copy a resource from one URL to another)
- MKCOL (to create a new collection of resources -- like a directory or folder)
- PROPPATCH (to add properties to a resource or collection)
- PROPFIND (to get properties from a resource or collection)
- LOCK (to lock a file so that no one else can change it while you're working on it)
- UNLOCK (to unlock the file)
Soon, WebDAV will support:
This function will provide the ability to store important revisions of a document
for later retrieval. Version management can also support collaboration by
allowing two or more authors to work on the same document in parallel tracks.
- Advanced Collections
This function will provide the ability to add a
"shortcuts" (or "symbolic links") to a collection; these links can point to any resource on the Web. Additionally, ordered collections allow a client to
specify a persistent ordering of resources in a collection.
- Access Control
This function will control who can look at or change a given resource.
The DAV Searching and Locating (DASL) group
is a related WebDAV group that is working to develop an interoperable means of
searching a WebDAV-compliant repository.
The main function of DASL is the ability to
search for web resources based on client-specified queries. Resources can be located based upon their property values and text content.
I recommend the excellent WebDAV.org site for more information.