HTML Is Dead A Web Standards Update Brian

HTML Is Dead! A Web Standards Update Brian Kelly UK Web Focus UKOLN University of Bath Email B. Kelly@ukoln. ac. uk URL http: //www. ukoln. ac. uk/ UKOLN is supported by: A centre of expertise in digital information management www. ukoln. ac. uk

Contents • Introduction • Standards • The Original Web Architecture • Architectural Developments • Deployment Issues • Discussion Aims of Talk • To give brief overview of Web architecture • To describe developments to Web standards • To briefly address implementation models A centre of expertise in digital information management 2 www. ukoln. ac. uk

Standards in an Educational / Research Context Standards are important in a public sector context (e. g. education, research, central & local government, . . . ) context to: • • • Ensure widespread access to resources Enables resources to be reused and repurposed Ensure scholarly resources can be preserved Address accountability of public funding Minimise resource costs for upgrading systems Provide universal access to resources (cf disability legislation) A centre of expertise in digital information management 3 www. ukoln. ac. uk

Standards 4 Standards Before the Web Access to resources typically required use of software vendor’s software – which was only available on limited no. of platforms. Often the software would be licensed. The goal of the Web was to provide universal access to resources. Who could argue with this goal? Need for standards to provide: • Platform and application independence • Avoidance of patented technologies • Flexibility and architectural integrity • Long-term access to data Ideally look at standards first, then find applications which support the standards. However it can be difficult A achieve this ideal! www. ukoln. ac. uk tocentre of expertise in digital information management

Standards 5 Standards and the Web HTML extensions PDF and Java? Proprietary • De facto standards • Often initially appealing (cf Power. Point, PDF) PNG • May emerge as W 3 C HTML ISO standards • Produces W 3 C • Produces ISO Z 39. 50 Recommendations Java Standards on Web protocols • Can be slow moving • Managed approach to and bureaucratic developments • Produce robust • Protocols initially standards IETF developed by • Produces Internet W 3 C members Drafts on Internet protocols • Decisions made by • Bottom-up approach to developments W 3 C, informed HTTP • Protocols may be developed by member & URN by interested individuals public review • "Rough consensus and working whois++ A centre of expertise in digital www. ukoln. ac. uk HTML, XML, PNG, … information management code"

Standards The Case For W 3 C Standards Why use open standards developed by the W 3 C? Why not leave it to the marketplace? J W 3 C’s open standards have been developed in an open environment, with the aim of achieving platform and application independency L Commercial companies develop proprietary formats in order to maximise their profits and dividends to shareholders J W 3 C’s open standards have been developed to interoperate with each other according to W 3 C’s design vision L Commercial companies typically develop proprietary formats in isolation, or along the lines of a company vision A centre of expertise in digital information management 6 www. ukoln. ac. uk

Standards, Architectures, Applications, Resources This talk touches on several areas Standards: concerned with protocols and file formats Open standards vs. Proprietary HTML / XML vs. PDF CSS / XSL vs. HTML GIF vs PNG Applications: software products used to implement systems Architectures: models for implementing systems Which standards are applicable NT / Unix File system / database application HTML tools / content management Resources: financial and staff costs needed to implement systems Apache / IIS Development vs. Migration costs Front. Page / Dreamweaver Use of in-house expertise Oracle / SQLServer In-house vs. out-sourced Cold. Fusion vs ASP information management Licensed vs. open source A centre of expertise in digital www. ukoln. ac. uk 7

Standards GIF As an example of the dangers of use of proprietary solutions, consider the GIF file format: • Unisys announce that they hold patent to compression algorithm used in GIF images and users of GIF will have to pay • Following much debate, Unisys require payment for licence from software developers - and also for end users of unlicensed software ($5, 000!) • Web community responds with PNG format • See <http: //burnallgifs. org/> WARNING: • There is no guarantee that payment will not be required for proprietary file formats which are currently free A centre of expertise in digital information management 8 www. ukoln. ac. uk

How Does The Web Work? The Web has three fundamental concepts: • URLs: addresses of resources • HTTP: dialogue between client and server • HTML: format of resources Web Browser The Netsoft home page Welcome to Netsoft 9 1 User clicks on link to the address (URL) http: //www. netsoft. com/hello. html 2 Browser converts link to HTTP command (METHOD): Connect to computer at www. netsoft. com GET /hello. html 3 Remote computer sends file Web server A centre of expertise in digital information management 4 Local computer displays HTML <HTML> <TITLE>Welcome</TITLE>. . The <A HREF=“…”> Netsoft</A> home page file www. ukoln. ac. uk

Data Formats Approaches To HTML Emphasis on managing HTML resources inappropriate: • HTML is an output format, which cannot easily be reused (e. g. WAP, e-Books, etc. ) • Need to manage HTML fragments (only partly achievable with SSIs) • Need to manage collections of resources • Need to have single master source of data • Need to support new developments such as personalisation • Difficult to integrate with new formats Issues • Should we stop giving HTML training courses? • Should we digital information management A centre of expertise instop buying HTML authoring tools? 10 www. ukoln. ac. uk

Data Formats XML: • • Extensible Markup Language A lightweight SGML designed for network use Addresses HTML's lack of evolvability Arbitrary elements can be defined (<STUDENTNUMBER>, <PART-NO>, etc) • Agreement achieved quickly - XML 1. 0 became W 3 C Recommendation in Feb 1998 • Support from industry (SGML vendors, Microsoft, etc. ) • Support in latest versions of Web browsers A centre of expertise in digital information management 11 www. ukoln. ac. uk

Data Formats XML Concepts (1) Well-formed XML resources: Make end-tags explicit: <li>. . . </li> Make empty elements explicit: <img. . . /> Quote attributes <img src="logo. gif" height="20" Use consistent upper/lower case and are different XML Namespaces: Mechanism for ensuring unique XML elements: <? xml: namespace ns="http: //foo. org/ 1998 -001" prefix="i"> Insert <i: PART>M-471</i: PART> A centre of expertise in digital information management 12 www. ukoln. ac. uk

Data Formats XML Concepts (2) XML Schemas • Allow constraints to be applied on XML attributes • Express shared vocabularies and allow machines to carry out rules made by people • Richer than DTDs • See <http: //www. w 3. org/XML/Schema> XSLT • A language for transforming XML from one DTD to another, or to another format (e. g. PDF) • Written in XML • Knows about XML (e. g. tree structures, etc. ) • See <http: //www. xslt. com/> A centre of expertise in digital information management 13 www. ukoln. ac. uk

Data Formats XML Concepts (3) England XLink sophisticated hyperlinking: France • Links that allow you to choose multiple destinations • Bidirectional links • Links with special behaviours: • Expand-in-place / Replace / Create new window • Link on load / Link on user action • Link databases • See <http: //www. xml. com/pub/a/2000/09/xlink/> XPointer • Provides access to arbitrary portions of XML resource • See <http: //www. w 3. org/TR/xptr/> A centre of expertise in digital information management 14 www. ukoln. ac. uk

Data Formats Getting to XML With XHTML: • HTML represented in XML • Some small changes to HTML: q Elements in lowercase not q Attributes must be quoted <img src="logo" height="50"> q Elements must be closed: . . . ) <img src="logo". . . /> • Gain benefits from XML • Tools available (e. g. HTML-Kit from http: //www. chami. com/html-kit/) • See <http: //www. webreference. com/xml/ column 6/>, <http: //groups. yahoo. com/ group/XHTML-L/> and <http: //www. ariadne. ac. uk/ issue 27/web-focus/> A centre of expertise in digital information management 15 www. ukoln. ac. uk

Data Formats CSS: • Cascading Style Sheets • XHTML/XML defines structure, CSS describes the appearance • CSS 1. 0 and 2. 0 now W 3 C recommendations • CSS 3. 0 in preparation (modularised) • We should be using CSS: q q Part of architecture Ease of maintenance Becoming much richer Accessibility • See <http: //www. w 3 c. org/Style/CSS/> A centre of expertise in digital information management 16 www. ukoln. ac. uk

Data Formats SVG: • Scalable Vector Graphics • A language for describing two-dimensional graphics in XML • See <http: //www. w 3. org/Graphics/SVG/ Overview. htm 8> • Also see presentation on XML written in SVG at <http: //www. w 3 c. org/Talks/2001/12/ IH-Euroweb/W 3 CIn. The. Worldslide. svgz> • WWW 2002 talk at <http: //www. w 3 c. org/2002/Talks/ www 2002 -SVG/> A centre of expertise in digital information management 17 www. ukoln. ac. uk

Data Formats A centre of expertise in digital information management 18 www. ukoln. ac. uk

Data Formats SVG Example http: //www. karto. ethz. ch/neumann/cartography/vienna/ www. ukoln. ac. uk A centre of expertise in digital information management 19

Data Formats SVG and XSLT This example: http: //people. w 3. org/maxf/Chess. GML/ • Originally written in Java • Author realised that XSLT would be easier • Uses SVG for chess board and pieces • Uses XSLT to move pieces A centre of expertise in digital information management 20 www. ukoln. ac. uk

CML, SVG and XSLT http: //www. adobe. com/svg/demos/cml 2 svg/html/index. html A molecule described in CML can be transformed using XSLT into SVG, allowing it to be displayed and manipulated A centre of expertise in digital information management 21 www. ukoln. ac. uk

Data Formats SMIL: • Synchronized Multimedia Integration Language • A language for authoring of interactive audiovisual presentations • Allows you to synchronize text, images, audio and video in a document • An XML Application • See <http: //www. w 3 c. org/Audio. Video/> A centre of expertise in digital information management 22 www. ukoln. ac. uk

http: //www. reseau. it/smilapp_en. html SMIL Example http: //www. kevlindev. com/tutorials/ basics/animation/svg_smil/index. htm A centre of expertise in digital information management 23 www. ukoln. ac. uk

Math. ML: • An XML application for maths • Various plugins, dedicated readers, etc. • Mozilla renders natively See <http: //www. mozilla. org/projects/mathml/> A centre of expertise in digital information management 24 www. ukoln. ac. uk

Data Formats Modularisation How can you: • Include XML resources such as Math. ML, Chem. ML, etc in XHTML documents? • Provide a subset of XHTML features in browsers on devices such as mobile phones, PDAs, etc. ? The answer is: • XHTML modularisation (modularization ) • See <http: //www. w 3. org/TR/xhtml-modularization/> and <http: //www. xml. com/pub/a/2002/01/16/ xhtml-m 12 n. html> A centre of expertise in digital information management 25 www. ukoln. ac. uk

Web Standards Part 2 –Deployment Issues A centre of expertise in digital information management 26 www. ukoln. ac. uk

W 3 C Challenges W 3 C faces a number of challenges: • Commercial acceptance (cf. browser wars): • Software vendors may refuse to deploy new standards • User acceptance: • User may not use of new standards (it's too complex / expensive, …) • Patent issues • Software vendors may claim patents on new standards • Complexity • The wide range of new standards makes deployment too difficult • Organisational issues • W 3 C is facing too many difficulties in growth, politics, etc. A centre of expertise in digital information management 27 www. ukoln. ac. uk

Deployment Architectures Let us consider the following areas: • Content Management • Access (Browser support) A centre of expertise in digital information management 28 www. ukoln. ac. uk

Deployment Position Today What should we be doing today? • Move away from creating new content in HTML • Move to XHTML as part of the migration • Deploying XML applications • Storing structured information in a neutral database • Using a CMS to manage our content • Deploying B 2 B applications to avoid human bottleneck (such as RSS) Note that these are aspirations. We will, of course, be constrained by existing systems, resource implications, vested interests, inertia, etc. A centre of expertise in digital information management 29 www. ukoln. ac. uk

Deployment 30 The CMS To The Rescue HTML authoring tools have limitations (as has HTML). A CMS (Content Management System): • Allows fragments to be managed • Allows collections to be managed • Allows resources to be stored in a neutral format (backend database) • Allows resources to be reused • Often provides access control • Often provides workflow processes and project management Issues • CMS can be expensive • CMS can be free but have support implications A centre of expertise in digital information management • Which one to choose? www. ukoln. ac. uk

Browser Issues Which approach to browser issues should you take? Web sites should be usable to old browsers as these are still in use and we aim to maximise access. Therefore you should deliver HTML 3. 2 / 4. 0 and avoid technologies such as Java. Script and CSS. NOTE Old browsers are broken and fail to • Use of ‘clean’ HTML should implement new technologies which degrade gracefully provide (a) richer functionality (b) • XHTML is a useful transition support for new devices and (c) better support for people with • User-agent negotiation may be relevant disabilities. QUESTION Therefore you should use the latest • Should organisations / stable versions of HTML (XHTML), community implement a CSS, etc. A centre of expertise in digital information management www. ukoln. ac. uk 31 browser policy?

Conclusions To conclude: • The Web has not yet stabilised • New developments provide needed functionality or address current limitations • However W 3 C cannot guarantee that its vision will necessarily be implemented • There is therefore a risk and a cost in adopting new standards • There is also a risk in failing to adopt new standards! • Keeping up-to-date is therefore essential! A centre of expertise in digital information management 32 www. ukoln. ac. uk

Questions Any questions? A centre of expertise in digital information management 33 www. ukoln. ac. uk