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Overview
Web-based Distributed Authoring and Versioning (RFC 2518)
defines the HTTP extensions necessary to enable distributed web
authoring. WebDAV provides a network protocol for creating interoperable,
collaborative applications, making the Web a collaborative, writable
medium. Important! WebDAV is not yet fully implemented
in the Sambar Server. Features will be introduced over the course of the
4.4 beta cycle. Initially, enabling WebDAV in the config/config.ini
file will expose the Versioning system via
the Document Manager, and allow users other than
the system administrator to use the functionality of the Document Manager.
Major features of the protocol include:
- Locking (concurrency control): long-duration exclusive and
shared write locks prevent the overwrite problem, where two or more
collaborators write to the same resource without first merging changes.
To achieve robust Internet-scale collaboration, where network connections
may be disconnected arbitrarily, and for scalability, since each open
connection consumes server resources, the duration of DAV locks is
independent of any individual network connection.
- Properties: XML properties provide storage for arbitrary metadata,
such as a list of authors on Web resources. These properties can be
efficiently set, deleted, and retrieved using the DAV protocol.
DASL, the DAV Searching and Locating
protocol, provides searches based on property values to locate
Web resources.
- Namespace manipulation: Since resources may need to be copied or
moved as a Web site evolves, DAV supports copy and move operations.
Collections, similar to file system directories, may be created and listed.
The Sambar Server Pro will include a Class 1 and Class 2
DAV server (see webdav.org) following
RFC 2518. In addition, versioning support
has been implemented in the server; there has been no attempt to
follow or conform to any specifications of the WebDAV Versioning
working group (DeltaV).
As the WebDAV Versioning project nears completion, the Sambar Server
will be brought into compliance with the specification.
Important! Existing versioning functionality (i.e. metadata)
may change if required for WebDav Versioning compliance; backwards
compliance will be maintained if at all possible.
The terrific work of Greg Stein on the
mod_dav Apache project
served as a reference implementation for the work in the Sambar Server.
Where the specification and mod_dav differed, the Sambar Server follows
the mod_dav 1.0.1 implementation.
This product includes software developed by Greg Stein <gstein@lyra.org>
for use in the mod_dav module for Apache (http://www.webdav.org/mod_dav/).
Security
DAV allows users to place and manipulate files in a directory
on your web server. To ensure security of user files, a
Sambar Server user login is required to access a DAV
repository (there is presently no anonymous access allowed).
Furthermore, all .htaccess and security.ini security
constraints are enforced on DAV resources.
Futures
The DAV specification does not provide document management capabilities
or workflow. DAV is an underlying protocol.
The Document Manager provided by the Sambar Server
will continue to be enhanced to expose more of the WebDAV functionality
as it is implemented. In addition, workflow and triggers will likely be
implemented in the underlying versioning system
provided with the Sambar Server.
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