Integration Concepts

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We need to explore several new concepts in order to build a portal that can meet the integration needs of an organization. Our goal is to open the portal to support automated transactions. To do so, we need to set up automated business processes that conform to business process structures. The integration should support secure, one-time data entry and automate the response to the user .

You could build a custom system that handles transactions in this way from the ground up, which would be the old-fashioned way. A point-to-point connection might be the most direct and efficient approach to allow two systems to talk to one another. But even in the simplest instance, the code would grow more complex over time and ever more difficult to maintain. Furthermore, as you made more and more connections between systems, this dark cloud of bespoke code would become a dangerous thunderstorm . Investing in an underlying infrastructure to support transactions between systems reduces the effort for each new interface and simplifies management and maintenance.

Integration standards that have become widely adopted in the past five years make it more feasible to create an EAI architecture. Many services are already available as web services, from credit card processing to geographic information systems.

The rest of this chapter will be easier to digest if you preprocess a few acronyms and terms. The following are keys to understanding the integration puzzle:

  • Enterprise application integration (EAI) . The general term for linking applications with one another, particularly heterogeneous applications that cross network and organizational boundaries. You can find general information including EAI case studies at the EAI Industry Consortium (www.eaiindustry.org).

  • Electronic Data Interface (EDI) . A dominant standard for legacy EAI developed in the 1960s for the transportation industry. EDI has the reputation of being complicated and expensive to build and maintain. It is typically run over a private network called a value-added network (VAN).

  • Automated business processes . Transactions that behave according to an agreed protocol and data model. An automated business process is designed to minimize errors and exceptions that require manual intervention.

  • Message-oriented middleware (MOM) . Software that supports the reliable exchange of data using asynchronous communication protocols and synchronous APIs.

  • Simple Object Access Protocol (SOAP) . This important standard dictates how structured documents (XML) are exchanged between peers in a decentralized, distributed environment. It is the fruit of the W3C XML Protocol Working Group and is now being updated from version 1.1 to 1.2. SOAP nodes send essentially one-way messages in a stateless environment, and they are combined in ways to handle more sophisticated transactions. They can also handle errors that arise. SOAP envelopes are the containers for messages; they can in turn hold zero or more header blocks and one or more body blocks. These blocks contain the data to be processed .

  • Web Services Description Language (WSDL) . The XML format that describes a web service, often used in conjunction with SOAP.

  • Extensible markup language (XML) . XML is a text language for representing data. It is self-describing , which means that it contains tags that explain the data model stored in the document. Therefore an XML document contains both data and metadata.

  • Multipurpose Internet Mail Extensions (MIME) . Messaging middleware that provides secure messaging to transmit and receive XML documents.

  • Extensible Stylesheet Language Transformation (XSLT) . The format in which an XML file is displayed.

  • XML schema . Schema contains the underlying data structure for an XML file, including validation rules. The schema is used to generate the form definition file (.XSF) used by InfoPath.

  • Document Object Model (DOM) . The document object model is a platform- and language-neutral interface used to programmatically address the contents of a document such as an XML document.

To put it all together, an EAI system is composed of components that create data files, often in the form of XML documents; communicate with one another using technologies such as MIME; orchestrate the processing of the transactions; and map the data from the source to the target, including processes enforcing business rules during the transformation. The existence of these open standards and commonly used protocols allows heterogeneous EAI systems to communicate with one another.

An EAI system can also be made available to end users such as customers through web forms. The following section describes alternative approaches for developing these forms on the Microsoft platform.

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Building Portals, Intranets, and Corporate Web Sites Using Microsoft Servers
Building Portals, Intranets, and Corporate Web Sites Using Microsoft Servers
ISBN: 0321159632
EAN: 2147483647
Year: 2004
Pages: 164

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