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James A. Senn’s
Information Technology, 3rd Edition
Chapter 12
Creating Web-Enabled
Applications
Senn, Information Technology, 3rd Edition
© 2004 Pearson Prentice Hall
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Objectives
• Describe the three principal forces behind the
interest in creating Web-enabled applications
in enterprises.
• Distinguish between the purposes of HTML
and XML in Web-enabled applications.
• Explain how XML aids in creating
interenterprise IT applications.
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Objectives (Continued)
• Identify the six advantages of XML.
• Explain the potential benefit of Web services to
enterprises IT applications.
• Identify and describe the three tools that
facilitate the user of Web services.
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Forces Behind Web-Enabled Systems
Definition
• Web-enablement:The tendency of systems
developers to incorporate features of the
Internet in enterprise systems.
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Forces Behind Web-Enabled Systems
Widespread Use of Browsers
• New computers shipped with Web browsers
• Large installed base of browser users
• Browsers appearing on other IT devices
• Intuitive features
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Forces Behind Web-Enabled Systems
Widespread Use of Browsers (Continued)
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Forces Behind Web-Enabled Systems
Widespread Use of Browsers (Continued)
• Flexibility
– Plug-ins: Software programs that extend the
capabilities of your Internet browser, giving
it added features.
• Universal front-end application
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Forces Behind Web-Enabled Systems
Legacy System
• Legacy System: Refers to the many mainframe,
midrange, client/server or PC applications that
are used to manage business functions.
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Forces Behind Web-Enabled Systems
Interconnected Enterprises
• Interoperability: The perfect exchange of data
and information in all forms (data, text, sound,
and image, including animation) between the
individual components of an application
(hardware, software, network).
• Heterogeneous Applications: May be written in
different programming languages, run on
different types of computers, and use varying
communications networks and transmission
methods.
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Extensible Markup Language
Definition
• Extensible Markup Language (XML):
Developers can design their own customized
markup languages for describing data.
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Extensible Markup Language
Structure of XML
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Extensible Markup Language
XML Advantages
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Extensible Markup Language
Document Type Definition
• Document Type Definition (DTD): Defines the
vocabulary (or standard) to make the data
easily understandable and useable.
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Extensible Markup Language
Document Type Definition (DTD) (Continued)
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Extensible Markup Language
Presentation Using XML Style Sheets
• Presentation Using XML Style Sheets
– XML Stylesheet Language (XSL): Created by
developers or publishers of XML data to
manage the display and presentation of
information in a document.
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Extensible Markup Language
Processing XML
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Extensible Markup Language
Processing XML (Continued)
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Web Services
Definition
• Web Services: Modular Internet applications
that perform a very specific function or task.
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Web Services
Web Services Principle
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Web Services
Simplified Object Access Protocol
• Simplified Object Access Protocol (SOAP): The
protocol used by an application to invoke a
Web service located on another computer.
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Web Services
Simplified Object Access Protocol
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Web Services
Web Services Description Language
• Web Services Description Language (WSDL):
Describes the capabilities offered by a specific
Web service as well as the protocols and
formats the service uses.
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Web Services
Web Services Description Language
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Web Services
Universal Description, Discovery, and
Integration
• Universal Description, Discovery, and
Integration (UDDI): A worldwide directory for
registering, finding, and using Web services.
– Yellow Pages: Describe the services offered
by UDDI.
– Green Pages: Describe how an application
can use the Web Services.
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Web Services
Universal Description, Discovery, and
Integration (Continued)
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