1 grønbæk, sloth & Ørbækwww8 - webvise open hypermedia webvise: browser and proxy support...

1 Grønbæk, Sloth & ØrbækWWW8 - Webvise open hypermedia

Webvise: Browser and Proxy Support for Open Hypermedia Structuring

Mechanisms on the WWW

Kaj Grønbæk, Lennert Sloth, & Peter Ørbæk

InterMedia - Aarhus

University of Aarhus

{kgronbak,les,poe}@intermedia.au.dk


…or addressing the challenge:

“- if you notice a connection make a link!”(Tim Berners-Lee, this mornings keynote)


Plan

What is open hypermedia?

The Webvise open hypermedia service for the Web• The Webvise client for authoring and browsing

• The Webvise proxy service for read-only browsing

• (Demo)

Application domains

Work in progress

Status and conclusion


Link object

I medfør af § 93, stk. 2 i bekendtgørelse nr. 1053 af 18. december 1995 om levnedsmiddelhygiejne og egenkontrol m.v. og § 20, stk. 2 i bekendtgørelse nr. 931 af 6. december 1995 om materialer og genstande bestemt til at komme i berøring med levnedsmidler fastsættes:

Ændringsbekendtgørelse nr. 1053 af 18. juli 1997 om .....

Open hypermedia for the WWW

Users may create their own structures (links, collections, annotations etc.) on the Web

Structures (contexts) are stored in separate databases

Many layers of structure on top of the same Web documents

Users may apply one or more layers at a time


Combining structure and content

www.xxx.com www.daimi.au.dk

Content: Arbitrary Web

pages

Structures: links, notes, guided tours

WebviseClient or Proxy

Combined HTML, etc.

(Contexts of structure for

various subject areas)


Open hypermedia basic architecture

Uses standard on-the-wire protocols (TCP/IP and HTTP)

OHP: Open Hypermedia Protocol - standards proposal put forward by OHSWG (http://www.ohswg.org)

Standard on-the-wire operation format: XML

Web serverOffice apps.

Applications

StructureServer

Hyperstore

OHP

Office apps.Web Browsers

MS IE NS C

NavLets

Webvise

HSP

JDBC/ODBC

Proxy

Web server


Datamodel for open hypermedia structures

Extensible model

Open for new structuring mechanisms

Open for new locating methods

Open for collaboration

Object

IDtypenamepSpecIddescriptionscharacteristics

AbstractObject

urlcontentmimeTypecharacteristics

ContentSpec

equal

VersionIDSelectionSelectionContextSelectionType

LocSpec

equal

FwdAxisSetRevAxisSetOverrun

AxisLocNaLoc

Spec

HMObj

computationId

….

LinkContext

members

EndpointlinkIDdirectionanchorID

Node

contentSpec

PSpec

spec

Computation

InParamsOutParamsContentSpec

Execute

parentIDlocSpec

Anchor

endpointIDs


LocSpecs: Locating segments of data

A locSpec is used to specify a certain location within a node’s content

LocSpecs use several attributes to hold location information: • Reference, Selection, Selection context, Axis specification.

• In most cases one of these attributes is sufficient

Example: Text document• Reference: a bookmark ID or a HTML target name

• Selection: the text of the span to search for

• Selection context: some surrounding text

• Axis: a position, such as start position, and stop position

Detecting and repairing inconsistencies


Examples of open hypermedia protocol (OHP) operations

NewLink: request = (MessageHeader, (endpoint)*, linkType, HyperSpace)

Ex.: <messageHeader> <uid>[email protected]</uid> <applName>webBrowserViaHyperviseCl</applName> <opCode>0</opCode></messageHeader><endpoint> <id>0</id> <name>Announcements</name> <direction>3</direction> <refspec> <contentspec> <version>v1.0</version>

<url>http://www.daimi.aau.dk/Realindex.html</url> <attributes>

<name>baseUrl</name><value>[url]http://www.daimi.aau.dk/[/url][frameName][/frameName]</value> <name>frameName</name><value>MAINWINDOW</value> <name>docTitle</name><value>DAIMI</value>

</attributes> </contentspec> <locSpec> <objectId></objectId> <structure></structure> <computation>Announcements</computation> <context>no graphics. Announcements: </context> </locSpec> </refspec> response = (LinkId, (EndPointId)*) Ex.:

FollowLink: request = (MessageHeader, contentSpec, locSpecList, direction)

Ex.: <messageHeader> <uid>[email protected]</uid> <applName>webBrowserViaHyperviseCl</applName> <opCode>202</opCode></messageHeader><contentspec> <version></version>

<url>http://www.daimi.aau.dk/Realindex.html</url> <attributes></attributes></contentspec><locSpec> <objectId></objectId> <structure></structure> <computation>Announcements</computation> <context></context></locSpec><direction>3</direction>

response = (ResponseCode, endpointList)


DEMO


Webvise user interface

Node Browser Link Browser

Current Context


Internet Explorer extension

Entries added to the context menu (right button menu)

COM communication with Webvise


Proxy server link decoration

Readers only interface

Visual indication on top of augmented pages

Anchor inserted bythe Webvise Proxyserver.

Floating Icon insertedby the WebviseProxy server. Itindicates who madethe annotation and itprovides access to theproxy settings.


MS Office integrations

Word and Excel extended with menu and toolbar

Supports seamless integration of local documents and Web documents

COM communication with Webvise

Webvise toolbar Webvise menu


Application domains

Works best with stable sources, such as:

Digital libraries

Document repositories on intranets

Law services

Specific examples:

Agricultural advisory service • help farmers in understanding environmental directions and laws

published on governmental servers.

Digital library usage in student projects

Site-Reviews• Journalist publishing Internet-based news sites


Work in progress: Collaboration Support

Collaboration on documents is coordinated by means of• Locking

• Event notification

• Versioning

A variety of modes for coupling users• Uncoupled

• Loosely coupled

• Tightly coupled


Work in progress: Link types

Types are used to distinguish among links with different semantic meaning

Examples:

Teachers may use link types such as "introductory", "experienced", and "advanced" to distinguish sources based on the knowledge required to read them.

They may discuss the quality of the sources, by introducing link types such as "recommend as primary reading", "recommend as background reading", "useless" etc.

The teachers may use the type mechanisms to generate filtered browsers, queries etc.


Conclusion and Status

Project undertaken in cooperation with TeleDanmark Internet - the biggest Danish Internet service provider• Stable prototypes being used for pilot experiments

Shares infrastructure with other services• Ariadne guided tour system (presented at WWW7)

• Mimicry system for linking in time-based media (also at WWW8)

Potentials for standardization of Internet protocols and datamodel for hypermedia based on external structures

Potential integrations with WebDav mechanisms for full blown authoring support

Prototype accessible from http://www.cit.dk/coconut

1 grønbæk, sloth & Ørbækwww8 - webvise open hypermedia webvise: browser and proxy support...

Documents

webvise proxy service

lennert sloth

conclusion slide

collaboration slide

time slide

guided tours webvise

web structures contexts

www kaj grnbk