Mani

SRM/MCA/HS 1

MC711 XML AND WEB SERVICES L T P C

3 1 2 4

PURPOSE :

The purpose of the course is to impart knowledge on eXtensible Markup Language (XML) and

to achieve secured, messaging through web services.

INSTRUCTIONAL OBJECTIVES:

At the end of the course, student should be able to:

Write a XML application using structure and presentation technologies

Apply XML manipulation technologies such as XSLT, XPath, XLink and XQuery

Do Program Manipulation and Dynamic access through DOM architecture

Develop web services and ensure security

Understand the need of semantic web

Role of XML, XML language basics, XML Revolution, XML Technology family, Simple XML

fie creation, and XML Namespaces

XML document rule, XML structuring, XML presentation technologies, XML Transformation,

XSLT, XQUERY, XLINK, XPATH

XML Parsers, XML DOM architecture, Classes of DOM family, Combining XML DOM and

XSL, Relational Database and XML

SOAP protocol, XML-RPC, HTTP, SOAP faults and SOAP attachments, Web services, UDDI,

XML security

Semantic web Technology, Layered Architecture, RDF and OWL representation

TOTAL 45

TEXT BOOK:

1. Frank. P. Coyle - XML, Web Services and the data revolution - Pearson Education, 2002

REFERENCE BOOKS:

1. Gavin Powel - Beginning XML Databases - Wrox Press, 2007 2. Ramesh Nagappan, Robert Skoczylas and Rima Patel Sriganesh, - Developing Java Web

Services - Wiley Publishing Inc., 2004

3. Grigoris Antoniou and Frank Van Harmelen,-A Semantic Web Primer - The MIT Press, Cambridge, Massachusetts London, England, 2004

4. Sandeep Chatterjee, James Webber, - Developing Enterprise Web Services -, Pearson Education, 2004

5. McGovern, et al., - Java Web Services Architecture -, Morgan Kaufmann Publishers, 2005

SRM/MCA/HS 2

MC0711 XML Web Services

S.N. Exercise Date of Completion

1-4. Simple XML file creation

5. Empty element

6. Root element

7. Child elements

8. XMLDOC Extensible

9. Attributes

10. Attribute to element conversion

11. Attribute as meta data

12. Including all options

13,14 Special Markup elements

15. Comment to exclude the document

16. Use firstobject editor, MSWord, MSExcel

17. XML and CSS Example for PI

18. Internal DTD implementation

19. External DTD implementation

20. DTD with CDATA

21. CDATA usage

22. XML schema

23. XML schema creation in .Net*

24. HTML file to validate schema based XML

25. XML- Schema validation Additional exercise

26. Step by step Schema Development Example

27. CSS Presentation

28. XSL formatting

29. XSLTransformation with various options

30. XSLT for-each sort element

31. XSLT if and choose, when element

32. XPATH implementation

33. Data in Tabular form

34. Implement XLINK*

35. XML DOM elements

36. XML ParseError elements

37. DOM Object Properties

38. Parse XMLDocument using XMLDOM

39. XML data access in .Net*

40. Web Services : .Net, Java*

* Demo Only

Staff Signature

SRM/MCA/HS 3

Unit I: Role of XML, XML language basics, XML Revolution, XML Technology family,

Simple XML fie creation, and XML Namespaces

1. Introduction:

The Need of XML: There are three major aspects to extending the enterprise from a relatively

constrained network to the broad reach of the Web. The most commonly considered aspect is the

business-to-consumer (B2C) connection, exploiting opportunities that abound in online

commerce. Another area is the business-to-employee (B2E) connection, adding efficiencies in

operations and customer contact by using the Web instead of proprietary networks. A third area,

and one of particular interest to businesses trying to survive in competitive environments, is the

business-to-business (B2B) connection made possible by the Web. Together, these opportunities

are driving what is seen as the extended enterprise, a mix of traditional networks and the loose

space of the Web.

2. History of Markup Languages

Markup is a method of conveying metadata (information about another dataset).

GML (General Markup Language)

SGML (Standard Generalized Markup Language) SGML-based markup languages all use literal

strings of characters, called tags to delimit the major components of the metadata, called

elements

HTML (part of sgml for internet) - deals presentation of data . pioneered by tim-lee

But no reusability of data ie) data retrieval not possible Few tags of HTML are not having end

tags

XML (root from SGML) . only for representation of data . structuring

For browser side no better technology than HTML

SRM/MCA/HS 4

The issues with HTML

Merits: Shortcomings:

Very easy to use & learn

Presentation technology

It is the most popular

NOT a data technology

Poor Searching

There is no Intelligence of content/data

We loose meaning association with content

Data cannot be represented hierarchically

Limited set of tags

XML Vs HTML

Similar in appearance

Both are based on SGML

BUT

XML describes data (XML was designed to transport and store data, with focus on what data is )

HTML displays data (HTML was designed to display data, with focus on how data looks )

The W3C developed ten design goals for XML, to quote from the Recommendation: The design

goals for XML are:

i. XML shall be straightforwardly usable over the Internet. ii. XML shall support a wide variety of applications.

iii. XML shall be compatible with SGML. iv. It shall be easy to write programs that process XML documents. v. The number of optional features in XML is to be kept to the absolute minimum,

ideally zero.

vi. XML documents should be human-legible and reasonably clear. vii. The XML design should be prepared quickly.

viii. The design of XML shall be formal and concise. ix. XML documents shall be easy to create. x. Terseness in XML markup is of minimal importance.

3.What is XML ?

XML stands for EXtensible Markup Language

XML is a markup language much like HTML

XML was designed to carry data, not to display data

XML tags are not predefined. You must define your own tags

XML is designed to be self-descriptive

XML is a W3C Recommendation

SRM/MCA/HS 5

XML (eXtensible Markup Language) provides a standards-based method for describing data.

XML)is a simple data description language with profound implications. XML has the ability to

describe data using a simple grammar that is highly interoperable among the many

heterogeneous systems that are connected to the Internet. XML has a several key strengths that

have helped it to become the de facto method for describing data:

XML is a text-based language, which makes it easily readable and more portable than binary data format

XML give the ability to define your own tags to describe data and its relationships to other data

XML strictly enforces its language syntax, unlike HTML.

Parsers are widely available to accurately parse and validate XML structure that you define, which means you dont have to do it yourself.

It is a meta language defined by w3C and it is open standards. XML is a set of rules and

guidelines for describing structured data in plain text. It can be read by any existing

language/tools which makes xml is a common message communication over SOAP protocol for

exchanging data. All the tags in XML are user defined tags.

All XML file should have

(i) processing instructions (ii) all tags should have end tag and properly nested (iii) all xml should have root element (iv) case sensitive

The rules of XML is checked by parser. (parser does not change format of file, only checks but compiler checks the syntax and change the file into another format)

well formed xml file is parsed and valid by parser.

XML is a o platform-independent, o self-describing, o expandable, o standard data exchange format o that can be used either independently or o embedded and used within other solutions. o Describes the information, not the presentation. Format flexible. o Derived as a subset of SGML o Allows you to define your own tags : Example: Dec 06, 2006 o XML: YAG (own Tags) o HTML: YAG (Predefined tags) o Provides meaningful & readable data o Meaning searches can be performed o Much simpler than SGML, SGML spec = 300 pages, XML = 33 pages o Purely a Data Technology o Supports compound documents

SRM/MCA/HS 6

XML Separates Data from HTML: With XML, data can be stored in separate XML files. This

way you can concentrate on using HTML for layout and display, and be sure that changes in the

underlying data will not require any changes to the HTML.

XML Simplifies Data Sharing: In the real world, computer systems and databases contain data in

incompatible formats. XML data is stored in plain text format. This provides a software- and

hardware-independent way of storing data. This makes it much easier to create data that can be

shared by different applications.

XML Simplifies Data Transport: One of the most time-consuming challenges for developers is to

exchange data between incompatible systems over the Internet. Exchanging data as XML greatly

reduces this complexity, since the data can be read by different incompatible applications.

XML Simplifies Platform Changes: Upgrading to new systems (hardware or software platforms),

is always time consuming. Large amounts of data must be converted and incompatible data is

often lost. XML data is stored in text format. This makes it easier to expand or upgrade to new

operating systems, new applications, or new browsers, without losing data

XML Makes Your Data More Available: Different applications can access your data, not only in

HTML pages, but also from XML data sources. With XML, your data can be available to all

kinds of "reading machines" (Handheld computers, voice machines, news feeds, etc), and make it

more available for blind people, or people with other disabilities.

XML advantages:

Web based Extensible License-free Platform independent Single end-to-end IT solution for electronic information exchanges Lower cost than EDI Easy to interpret Domain specific vocabulary Data interchange between different system

XML has had an impact across a broad range of areas. The following is a list of some of the

factors that have influenced XML's adoption by a variety of organizations and individuals.

XML files are human-readable. XML was designed as text so that, in the worst case,

someone can always read it to figure out the content. Such is not the case with binary data

formats.

Widespread industry support exists for XML. Numerous tools and utilities are being

provided with Web browsers, databases, and operating systems, making it easier and less

expensive for small and medium-sized organizations to import and export data in XML

format.

Major relational databases now have the native capability to read and generate XML data.

SRM/MCA/HS 7

A large family of XML support technologies is available for the interpretation and

transformation of XML data for Web page display and report generations.

XML integrates with standard Web protocols such as HTTP and FTP.

4.Role of XML:

XML is a specification for defining new markup languages. XML is a meta-language (literally a

language about languages) defined by the World Wide Web Consortium (W3C), one of the main

organizations driving the push to open Web standards. In its simplest sense, XML is a set of

rules and guidelines for describing structured data in plain text rather than proprietary binary

representations. However, as a phenomenon, XML goes beyond its technical specification. Since

its standardization by the W3C in 1998, XML has been the driving force behind numerous other

SRM/MCA/HS 8

standards and vocabularies that are forging a fundamental change in the software world. XML

has enabled industry vocabularies and protocols.

5.XML Language Basics

XML is simple. Technically, it's a language for creating other languages based on the insertion of

tags to help describe data. However, XML is actually more than just tags.

XML is a combination of tags and content in which the tags add meaning to the content. The

following is a simple XML markup of customer information. Start tags such as begin an

element that contains the actual data. End tags such as mark the end of an element

definition.

John von Neumann

914.631.7722

914.631.7723

[email protected]

For a company like ZwiftBooks, deciding on an XML representation for their data is a first step.

In trying to come up with an XML data vocabulary that may be useful in automating operations,

it's helpful to examine use cases that describe what occurs during a business interaction. Figure

2.2 illustrates the essence of a ZwiftBooks customer request and response.

SRM/MCA/HS 9

XML elements:

XML Attributes:

SRM/MCA/HS 10

Exercise 1: Create a Simple XML file:

Fundamental XML

Surya

Intro

Java for Beginners

Sathya

Beginner

The first line is the XML declaration. It defines the XML version (1.0) and the encoding used (is

utf-8 character set). The next line describes the root element of the document . The next

lines describe the child elements , ,

Exercise 2:

Open a notepad and type the information and view it in a browser:

XML Design Principle:

There are three key design elements that by omission contribute to XML's success:

No display is assumed. Unlike HTML, XML makes no assumptions about how tags will be rendered in a browser or other display device. Auxiliary technologies such as style

sheets add this capability.

SRM/MCA/HS 11

There is no built-in data typing. DTDs and XML Schema provide support for defining the structure and data types associated with an XML document.

No transport is assumed. The XML specification makes no as sumption about how XML is to be transported across the Internet. This has opened the door to creative ideas about

delivering XML by means of HTTP, FTP, or Simple Mail Transfer Protocol (SMTP).

6.XML Revolution

The three revolutions: data, architecture, and software. the three areas of impact are data, which

XML frees from the confines of fixed, program-dependent formats; architecture, with a change

in emphasis from tightly coupled distributed systems to a more loosely coupled confederation

based on the Web; and software, with the realization that software evolution is a better path to

managing complexity than building monolithic applications

a) The Data Revolution

Data is now free to travel the Web. Prior to XML, data was very much proprietary, closely

associated with applications that understood how data was formatted and how to process it. Now,

XML-based industry-specific data vocabularies provide alternatives to specialized Electronic

Data Interchange (EDI) solutions by facilitating B2B data exchange and playing a key role as a

SRM/MCA/HS 12

messaging infrastructure for distributed computing. XML enables the creation of program-

independent data formats.

XML's strength is its data independence. XML is pure data description, not tied to any

programming language, operating system, or transport protocol. In the grand scheme of

distributed computing this is a radical idea. The implication is that we don't require lock-in to

programmatic infrastructures to make data available to Web-connected platforms. In effect, data

is free to move about globally without the constraints imposed by tightly coupled transport-

dependent architectures. XML's sole focus on data means that a variety of transport technologies

may be used to move XML across the Web. As a result, protocols such as HTTP have had a

tremendous impact on XML's viability and have opened the door to alternatives to CORBA,

RMI, and DCOM, which don't work over TCP/IP. XML does this by focusing on data and

leaving other issues to supporting technologies.

The Code, Data, Document Culture:

XML has emerged from a document culture. To understand XML's impact on the computing

world, it's useful to place XML in perspective. As Figure 1.9 shows, XML comes out of a

document culture that is distinct from the code and data cultures that are the hallmarks of the

mainstream computer industry. The code culture is characterized by a focus on programming

languages, beginning with FORTRAN and evolving through Algol to C, C++, and Java. The data

culture is characterized by COBOL, data processing, and databases. Both the data and code

cultures carry with them a built-in propensity to view the world through either a code or a data

lens. From a code perspective, data is something to be transported by procedure calls. From a

data perspective, data is something to be stored in databases and manipulated

Code and data have defined systems thinking. The late 1980s and early 1990s saw code and data

combine in the form of object-oriented languages such as C++, Smalltalk, Java, and Object

SRM/MCA/HS 13

COBOL. And yet, object technology was only a partial answer. As practitioners in the data world

had long realized, transactionsthe ability to update multiple databases in an all-or-none mannerare essential to serious industrial-strength enterprise applications. Because component frameworks provide transactions as a service to applications regardless of language origins, the

playing field quickly shifted from objects to components. Thus infrastructures such as CORBA,

DCOM, and Enterprise JavaBeans (EJB) provide interconnection, security, and transaction-based

services for extending the enterprise. In the mid 1990s, components were the only way to extend

legacy. However, XML changed the rules of the game.

XML opens up options for treating code as data. XML's emergence from the data-oriented

document culture has forced a rethinking about application development, particularly for those

accustomed to thinking of building applications from a code-based perspective. What XML

brings to the computing world is a technology that allows data to be freed from the constraints

created by code-centric infrastructures. Instead of requiring data to be subordinated to parameters

in a procedure call, XML now permits data to stand on its own. More radically, it allows code to

be treated as data, which has been the driving force behind using XML for remote procedure

calls. As Figure 1.10 illustrates, XML offers an alternative to both EDI and technologies such as

CORBA, RMI, and DCOM that lock data transfer into underlying networks and object

infrastructures. It is this change in perspective that is driving the widespread use of XML across

the entire computing industry and opening up new patterns of interaction, including Web

services.

b) The Architectural Revolution

Simplicity and the ability to combine different standards are driving forces behind W3C

deliberations . Together these XML-based technology initiatives open up new possibilities for

distributed computing that leverage the existing infrastructure of the Web and create a transition

from object-based distributed systems to architectures based on Web services that can be

SRM/MCA/HS 14

discovered, accessed, and assembled using open Web technologies. The focal point of this

change in architectural thinking has been a move from tightly coupled systems based on

established infrastructures such as CORBA, RMI, and DCOM, each with their own transport

protocol, to loosely coupled systems riding atop standard Web protocols such as TCP/IP.

Although the transport protocols underlying CORBA, RMI, and DCOM provide for efficient

communication between nodes, their drawback is their inability to communicate with other

tightly coupled systems or directly with the Web.

XML and the Web have enabled the loose coupling of software components. Loosely coupled

Web-based systems, on the other hand, provide what has long been considered the Holy Grail of

computing: universal connectivity. Using TCP/IP as the transport, systems can establish

connections with each other using common open-Web protocols. Although it is possible to build

software bridges linking tightly coupled systems with each other and the Web, such efforts are

not trivial and add another layer of complexity on top of an already complex infrastructure. As

Figure 1.11 shows, the loose coupling of the Web makes possible new system architectures built

around message-based middleware or less structured peer-to-peer interaction.

c) The Software Revolution

XML is part of a software revolution centered around combination and surprise. XML is also

part of a revolution in how we build software. During the 1970s and 1980s, software was

constructed as monolithic applications built to solve specific problems. The problem with large

software projects is that, by trying to tackle multiple problems at once, the software is often ill-

suited to adding new functionality and adapting to technological change. In the 1990s a different

model for software emerged based on the concept of simplicity. As Figure 1.12 illustrates,

instead of trying to define all requirements up front, this new philosophy was built around the

concept of creating building blocks capable of combination with other building blocks that either

already existed or were yet to be created.

SRM/MCA/HS 15

The Web is an example of the power of combination. Figure 1.13 illustrates how the Web as we

know it was not something thought out in strict detail. Each of the contributing technologies

focused on doing one thing well without inhibiting interconnection with other technologies. The

essential idea was to maximize the possibility of interaction and watch systems grow. The result

is the Web, a product of the confluence of forces that include the Internet, HTML, and HTTP.

Let's now look at how these same forces of combination and collaboration are driving the

revolution in software.

The power of combination is finding its way not only into software construction but up the

development chain to software specification and design. Rather than hoping to meet the needs of

users, design is now more collaborative, bringing in stakeholders early to ensure maximum

feedback and the benefits of collaborative thinking. Figure 1.14 illustrates how this collaborative

model is used by the W3C, the Internet Engineering Task Force, and Sun in its Java Community

SRM/MCA/HS 16

Process.

7.XML Technology Family

XML derives its strength from a variety of supporting technologies. XML is not just a

technology for defining data vocabularies. Surrounding XML is a wide variety of XML

standards and initiatives that act in combination with XML to address many of the issues

associated with bringing XML into mainstream computing, namely presentation, structure, and

transformation. As Figure 2.1 shows, the XML core includes XML itself, based on the XML 1.0

specification, and namespaces, the specification that allows XML documents from different

sources to be combined and yet be able to disambiguate elements with the same name from

different sources. Following is a list of other categories in the XML technology:

Structure and data types: When using XML to exchange data among clients, partners, and

suppliers, it's important to be able to define how XML documents should be structured.

DTDs and XML Schema provide this capability. DTDs come out of the world of

Standard Generalized Markup Language (SGML), focusing primarily on structure by

SRM/MCA/HS 17

specifying what elements and attributes are considered valid for a particular XML

instance document. DTDs have limited capability to specify data types, a circumstance

that can be explained historically by considering their origins in the document culture

(see Figure 1.9 in Chapter 1). XML Schema is a more recent initiative of the World Wide

Web Consortium (W3C) that puts a more conventional data processing spin on describing

XML data with more precision than with DTDs.

XML presentation technologies: In keeping with an important design pattern for robust

systems, XML intentionally separates data content from presentation through the

introduction of supporting technologies that focus on delivering content to users via a

variety of devices and presentation media. Among the technologies for presentation are

XHTML, a modular XML-conformant replacement for HTML; CSS for controlling the

display properties of HTML or XML in Web browsers; XSL and XSL Formatting

Objects (XSL-FO) for formatting XML for various output media; XForms for collecting

data from Web forms and returning XML; VoiceXML, for delivering content to voice-

enabled devices; and Wireless Markup Language (WML), for delivery to wireless

devices enabled for Wireless Application Protocol (WAP).

XML manipulation technologies: Manipulation technologies provide the capability to

extract and transform XML in different ways. These technologies play an important role

in server-based XML processing for business-to-business (B2B) data manipulation and

exchange. XSLT is widely used to transform XML from one format to another; XPath is

a technology used by other XML technologies to navigate through an XML tree structure

and zero in on particular elements or subtrees; XLink is a technology for creating and

describing links between resources and for enabling links that go beyond the simple

unidirectional links of the current Web; and XQuery is an evolving technology for

extracting and querying XML repositories.

Other related technologies: The XML family of technologies also includes initiatives for

working with metainformation, which is literally information about the information

contained in an XML document. Technologies in this space include RDF and InfoSet.

SRM/MCA/HS 18

The core of XML and its key components and extensions are:

XML 1.0 syntax, including Document Type Definitions (DTDs)

Namespaces in XML

XML Schema (or one of its alternatives or supplemental validation tools: XDR, SOX, RELAX, TREX, and The Schematron)

Some of the key features that are commonly required in XML applications.

Describing XML data structure: The XML Information Set (XML Infoset) and XML Path Language (XPath)

Navigating & Linking: XML Linking (XLink), XML Pointer Language (XPointer), XML Inclusions (XInclude), XML Fragment Interchange (XFI), and XML Query

Language (XQuery).

Transforming & Presenting: XSLT and XSL-FO (XSL Formatting Objects)

8.XML Namespaces:

Namespaces eliminates the ambiguity of the same name from different providers.

When developing xml documents, it is common to refer to element and attribute names that share

a common context as vocabulary. The possibility arises that an element or attribute in that

vocabulary may have a name that is identical to an element or attribute used by someone else in a

different vocabulary.

XML namespaces is a simple technology solution that allows element and attribute names to be

distinguished from the similarly named elements and attributes of other XML users. XML

namespace solve this ambiguity problem by associating explicit namespace (or vocabulary) with

elements and attributes in XML document. Thus a namespace is essentially a set of names in

which all the elements and attribute names can be guaranteed to be unique.

Figure 2.3 illustrates how a namespace may be used to disambiguate duplicate element names.

XML namespaces solves the problem of clashing names by providing for a unique prefix to be

attached to the beginning of element and attribute names. In practice, a company's Web address

is often used as the unique prefix, but technically the namespaces specification allows any

Uniform Resource Identifier (URI) to be used. URIs are more general than the common Uniform

Resource Locator (URL) and include just about any unique name one wants to use. The usual

result, though, is that when namespaces are used in an XML document, the official element name

is actually a two-part name: the name of the XML namespace plus the name of the element or

attribute.

SRM/MCA/HS 19

Namespace Declarations

There are several ways to add a namespace to an XML document so that, when software is

processing XML data from ZwiftBooks, it will see ZwiftBooks elements as

http://www.zwiftbooks.com:title instead of just title. The simplest approach is to declare a

namespace in a top-level element and let all the elements and attributes under the top element

come under the scope of the namespace. For example, the following XML document adds a

ZwiftBooks namespace to an XML book description document.

0-596-00058-8

XML in a Nutshell

Harold, Elliotte Rusty

In this example, the namespace declaration is applied to the book element by adding the

predefined attribute xmlns and giving as its value the unique URL of ZwiftBooks,

http://www.zwiftbooks.com. Because the xmlns attribute appears in the book element, all

subelements (isbn, title, and author) are included in the namespace.

Example 2:

This XML document carries information in a table:

Apples

Bananas

SRM/MCA/HS 20

This XML document carries information about a table (a piece of furniture):

African Coffee Table

80

120

If these two XML documents were added together, there would be an element name conflict

because both documents contain a element with different content and definition.

Using Namespace to avoid conflict:

This XML document carries information in a table:

Apples

Bananas

This XML document carries information about a piece of furniture:

African Coffee Table

80

120

Instead of using only prefixes, we have added an xmlns attribute to the tag to give the

prefix a qualified name associated with a namespace.

Figure 2.4 illustrates the use of multiple namespaces within the same document and how

namespaces are useful in distinguishing which elements are which. In this example, the top-level

element, supercatalog, is in its own namespace. Its two book subelements, technically within

the scope of the supercatalog namespace declaration, define their own namespaces, so that we

end up with three namespaces within the XML.

SRM/MCA/HS 21

Namespace Abbreviations

Namespace abbreviations may be used to simplify writing and reading the XML. The

namespaces specification also makes it possible to use abbreviations for namespaces in order to

make XML documents more readable. Figure 2.5 shows how we can define a shortcut name,

zbooks, so that anywhere that zbooks appears in a document, a software program processing the

document will replace it with the actual namespace, http://www.zwiftbooks.com.

SRM/MCA/HS 22

9. XML Vs EDI

EDI or Electronic Data Interchange is the exchange of information in a standard format between

computers without any human intermediary

It's difficult to define XML (eXtensible Markup Language) in one sentence because of its dual

function as a scripting language and a file format.

Both EDI and XML formats are structured to describe the data they contain. The main

difference would be that the EDI structure has a record-field-like layout of data segments and

elements, which makes the EDI file shorter, but not easily understandable; while the XML

format has tags, which is more easily understood, but making the file bigger and verbose.

EDI XML

Need defined rules Need defined rules

Structure is implicit Structure is explicit

Machine to Machine interaction Both Machine to Machine and Machine to

Human interaction

Widely used in large industries Widely used in large industries

Expensive for SMEs Cost effective for SMEs

Conversion capable for WWW WWW enabled