Ariadne — The Web Version Future Formats Brian

Ariadne - The Web Version: Future Formats Brian Kelly UK Web Focus UKOLN, University of Bath, BA 2 7 AY B. Kelly@ukoln. ac. uk http: //www. ukoln. ac. uk/ 1

Contents • Introduction • UK Web Focus • Ariadne Today • Document Formats • • HTML Style Sheets SGML Acrobat • Content Negotiation • Mobile Code • Conclusions 2

UK Web Focus: • Responsible for: – Technology watch – Dissemination of information – WWW coordination within UK HE community – Represents JISC on W 3 C • Based at UKOLN, University of Bath • Brian Kelly appointed from 1 st Nov 1996 3

Ariadne Today (1) Ariadne has a simple directory structure. Many subdirectories contain a single HTML file, possibly with a small number of images. Statistics - 25 Nov 96 321 HTML files 357 GIF files 7 JPEG files 4

Ariadne Today (2) Ariadne files are simple HTML (3. 2) documents Header: subject icon, title, introduction and standard iconic menu Body: written by author, sub-edited and checked by Ariadne editor Footer: copyright statement and standard iconic menu 5

HTML Developments HTML 2. 0 • First widely used HTML DTD HTML + / HTML 3. 0 • Plans for greater functionality Netscape / Microsoft HTML Extensions • Added new functionality • Lose browser independence • Architectural flaws HTML 3. 2 • New proposed specification (agreed by W 3 C, Netscape, Microsoft, …) 6

Formatting Tags Netscape and Microsoft introduced new formatting tags Many are: • Architecturally flawed • Contravene spirit of SGML (define document structure, not appearance) • Maintenance problems 7 Imagine a large Web site, with house style defined in every document. Consider maintenance load when changing house style.

Style Sheets separate formatting information from document structure HTML document <LINK REV=style HREF=. . > <H 1>Keep sweet!</H 1> <H 2 class=punk>. . . Style Sheet H 1 {font. style: Bold} H 2. punk {font. color: green} http: //www. w 3. org/pub/WWW/Style/ 8

SGML Is the future for HTML the integration with richer SGML DTDs? Panorama is an example of an SGML DTD-aware browser. 9

Adobe Acrobat 10 With Adobe Acrobat: • Greater control over layout • Hypertext links are possible • Netscape plugins available But • Lose document See http: //www. adobe. com/ structure • Proprietary

Content Negotiation In HTTP it is (or will be) possible for clients and servers to negotiate over preferred document formats (and HTML features? ) Client Give me the file welcome I prefer the French version. Give me the image logo. gif My PC only supports 16 colours. Give me welcome My browser supports tables, but not frames 11 Server Voilá. Here’s the file logo. 16 col. gif Here it is.

Cookies: • Provide state • A Netscape innovation, now in HTTP/1. 1 spec • Can be used for – Storing user preferences – User profiling 12 Ariadne Preferences Interface Frames - fixed Frames - floating No frames Content No Garfield carton Submit Cookies can also record user’s route through Ariadne

Frames are another example of a Netscape extension, but with architectural flaws: • Bundles user interface information with document content (cf. style sheets) • Lack of control by end user • Not liked by many users (e. g. users of low resolution PCs, PDAs, …) • Not possible to distinguish between documents with and without frames 13 Note that W 3 C propose implementation of frames using style sheets - see http: //www. w 3. org/pub/WWW/TR/ NOTE-layout. html

Floating Frames http: //www. j-g. com/java/popup. html There a number of ways of implementing user interfaces. This example shows how Java can be used to producing a floating navigational window 14

Mobile Code Mobile code (Active. X, Java) can be used to: • Proving functionality not available in HTML (e. g. pop-ups) • Viewing multiple file formats (universal viewers) • Running simulations • . . . 15

Collaborative Systems User feedback and interaction can be provided by: • Email • WWW-based discussion lists (can provide metadata, single location) 16 http: //union. ncsa. uiuc. edu/ Hyper. News/get/Free. html

Universal Access • “But I haven’t got the latest version of Netscape / Internet Explorer / …” • “My Computing Service doesn’t allow Java programs to be executed” • “I don’t have a computer!” • “I don’t look at the Web every day” Need to consider: • Use of content negotiation • Spec of end user systems • FAX gateways • Automated notification 17

Automated Notification Automated notification tools for changes to pages are available http: //www. netmind. com/URL-minder/new/register. html Netmind Netscape Smart. Marks 18

Support For Authors (1) Today: • Author emails article URL • Editor then processes article Why not: • Author uses file upload 19

Support For Authors (2) Checking services could be provided: • Spell checking • HTML validation • Link validation Possibility of: • Automated processing of incoming articles 20

Object-Oriented Approach Today we have a file-based system GET An object-oriented approach enables methods to be applied to objects METHOD view-Ariadne-article view-Netskills-article manage-Ariadne-article 21 File Based on ideas from W 3 Objects project at Newcastle Object Ariadne-header Article body Ariadne-footer

Objects and Ariadne View Manager Select view View type Article 22 Manager Reader Ariadne Other Manager View Article Spell check HTML validate Link check Use of object oriented Reader View technologies can provide: Article • Multiple views of same object Copyright link (e. g. different footers) Next Previous • Multiple methods on same Ariadne Home objects (e. g. invoke editor) For example see Byte at: http: //www. byte. com/art/9609/ sec 9/art 1. htm and W 3 Objects at http: //arjuna. ncl. ac. uk/w 3 objects/

Conclusions (1) Ariadne on the Web: • Should be based on sound underlying WWW principles • There are good reasons to make use of new technologies • But need to: – Keep in touch with mainstream readership – Be aware of resource implications in exploiting new technologies – Work with others who are using new technologies 23

Conclusions (2) Future developments for Ariadne : watching brief • Stylesheets - a must? • Other SGML DTDs (e. g. XML) • Other document formats (e. g. PDF) • Document Management System (e. g. object-oriented system) evaluation with • Content Negotiation Web Focus • Collaborative Systems • Mobile Code - pilot in small no. of articles 24