Washington, September 15-18, 1999 – London, November 21-24, 1999

Using XML for E-Commerce

Craig McQueen

XML – “a data format for structured document interchange on the Web”, http://www.w3.org/

E-Commerce – “The conducting of business communication and transactions over networks and through computers”, http://www.dictionary.com/

Introduction

The terms ‘XML’ and ‘E-Commerce’ are two of the most widely used terms when discussing the Internet today. They are being discussed together more often as well. What does it mean to build an E-Commerce system using XML? This presentation tries to answer that question by looking at the following:

Ø why XML is the language of E-commerce

Ø application servers that ‘talk’ XML

Ø integration with systems that don’t ‘talk’ XML

Ø current XML implementations

Ø steps to implementing your own XML definition

Throughout the discussion we will look at a mythical virtual company – WroxShop. We’ll also use the Digital Nervous System to set the context for the discussion.

Craig McQueen
Craig is a Principal Consultant at Sage Information Consultants, Inc. His role at Sage is to assist clients in adopting Internet technologies into their existing businesses. Recently, he built the middle-tier for an online banking application. He has participated with Wrox on many projects, including XML Applications and Professional Site Server. He has presented at many conferences and seminars - most recently, a seminar Bringing the Digital Nervous System To Life (a co-presentation with Simon Witts, General Manager of Microsoft Canada). Craig can be reached at cmcqueen@sageconsultants.com.

Digital Nervous System

The Digital Nervous System (DNS) is Microsoft’s model for describing how technology is integrated into the business processes of an organization. It controls the basic systems upon which an organization operates. If an organization’s DNS is healthy, its internal processes operate smoothly and quickly. The key to a healthy DNS is the effectiveness of how an organization manages the flow of its digital information.

The DNS does not just apply to the internals of a company; it has to do with an organization’s partners as well. A healthy DNS means a company is equipped to deals with its business partners in digital form. This extends the effectiveness of the DNS beyond the company’s boundaries.

E-Commerce

The potential benefits of e-commerce are: lower costs, greater customer reach, and faster response times. E-commerce is defined by digital relationships with customers and business partners. E-commerce requires technology that permits disparate systems to communicate. XML is a DNS enabler; it is the language of E-commerce.

XML Benefits

The benefits of using XML for E-commerce are the following:

Ø Application to Application communication

Ø Supported by World Wide Web Consortium

Ø Many tools available (some free!)

Ø Wide vendor support (Microsoft, IBM, Oracle, SAP…)

Ø Becoming part of the platform

Building WroxShop

The WroxShop is an online computer supplier. People can describe and order a computer via the Internet through WroxShop. WroxShop is designed to be lean and mean. The goal is for each employee to be focused on either business decisions or customer service. WroxShop does not want any employee doing manual tasks such as re-keying information or placing orders with suppliers over the phone.

To support such an operation, WroxShop has adopted XML and has found suppliers that accept XML transactions.

WroxShop also has an Enterprise Resource Planning system to run their operations. All financial transactions are placed through the ERP. Three areas WroxShop will have to consider when building their system is choice of application server, XML DTDs and schema and the development effort involved.

Application Server

Ø Web Server – A software application that responds to HTTP requests. In its most basic form, a web server “serves” files via HTTP.

Ø Application Server – A software application that ‘hosts’ other software applications. Many web servers are also application servers in that they execute a program (or script) to respond to an HTTP request.

Ø Integration Server – A software application that enables communication and interaction between disparate software applications. A web server may also be an Integration Server in that it knows how to interact with other integration servers.

A software application can be a web server, application server and an integration server. In the context of Microsoft product line, Internet Information Server (IIS) is a web server and application server. Microsoft Universal Data Access enables Integration for IIS through OLE DB Providers and ODBC. The future of Integration Servers is to act as an XML bridge. An Integration Server has plug-ins that convert application specific APIs to XML.

Examples of Integration Servers are webMethod’s B2B Server and Microsoft’s BizTalk server. Both will be discussed in a later section.

XML DTDs and XML Schemas

For systems to communicate, they have to have a common language to communicate with. XML 1.0 specifies the syntax of the language but not the domain specifics. Currently, two choices for defining the language: XML DTDs and XML-Schemas.

An XML DTD defines the grammar for a class of documents. It contains the elements, attributes, entities and notation that can be used within a document that conforms to that DTD. A XML document can be validated against a DTD to ensure the use of elements is correct but it cannot validate the content of the elements. Two main problems with DTDs are they are described with a different syntax than XML and they don’t have support for data typing since they cannot validate element content.

An XML-Schema on the other hand is described using XML syntax. By defining an XML-Schema, not only can you validate the elements used in a document but you can validate the content itself.

For WroxShop, they will have to decide which XML DTDs and Schemas they need to use with their Information Service and Suppliers.

Development

Much of the work of building XML E-commerce systems is configuring and connecting software and systems. You may need to programmatically walk-through an XML document. To do this there are many parsers freely available including Microsoft’s that comes with IE5 or is downloadable from http://msdn.microsoft.com/downloads/tools/xmlparser/xmlparser.asp. You will also have to write application connectors if one is not available for a particular system you want to interface with.

Customer to Application Server

The beginning of a web-based application is a customer using a web-browser to interact with an application server. Most often this involves an HTML form being sent over HTTP (or HTTPs) from the browser to the application server. The HTML form would contain a specific request, such as paying for an online purchase. For the WroxShop, this would be the customer passing their shipping address and credit card number to the WroxShop web application.

One problem with this model is customers have to continually enter their personal information (such as shipping address and credit card number) for each online purchase. A proposed solution is the Electronic Commerce Modeling Language (ECML).

Electronic Commerce Modeling Language (ECML)

In it’s current incarnation, ECML sounds fancier than it really is. ECML is a set of agreed upon field names to use in an HTML FORM. The following represents a form using ECML for entering credit card information.

<HTML>

<HEAD>

<TITLE> eCom Fields Example </TITLE>

</HEAD>

<BODY>

Please enter card information:

<P>Your name on the card

<BR>The card number

<BR>Expiration date (MM YY)

<BR>

</FORM>

</BODY>

</HTML>

The intent is various “Internet Wallets” (such as Microsoft Wallet) would look at the HTML document on the client and automatically fill out the information.

ECML is supported by American Express, AOL, Compaq, CyberCash, IBM, MasterCard, Microsoft, SETCo, Sun Microsystems, Transactor Networks, Trintech, and Visa.

Application Server to Information Service

Another area of XML in E-commerce is integrating other services into existing business processes. A simple example would be querying a courier company's web site to receive the status of a package via XML. WroxShop is thinking about integrating this information into customer purchase status information so the customer will know the shipping status of their computer.

An information service that is currently in production is Dun and Bradstreet’s Global Access project.

Dun and Bradstreet Global Access

As a leader in providing business-critical information, Dun and Bradstreet (D&B) wants to make sure they adapt to the global marketplace. Their Global Access aims to offer new data products generated from worldwide databases that is based on a consistent set of data elements. D&B wanted to place their information in a form that would be easy for customers to embed in their business process. To accomplish this goal D&B chose to use XML as their transaction and data definition language.

The XML application that D&B created is called Global Access Data Exchange (DGX). DGX looks after the messaging and transaction portion of the Global Access platform. DGX is composed of a set of records, each record designed to represent a transaction type between a Global Access Server and a client. D&B modeled DGX after Open Financial Exchange (OFX) since OFX is also a transaction based system.

WroxShop can pass a DGX request to the Global Access server to get credit information about a particular company. This way, WroxShop can decide in real-time if a company should be allowed to lease or not.

Application Server to ERP

True automation of a company’s business is hooking an application server into an Enterprise Resource Planning (ERP) system. The ultimate goal is to have one company’s ERP trigger a transaction that sends an XML message over the Internet that is received by another company's ERP system. A specific example is having a purchase order from one company automatically be sent to another company where a sales order is generated and returned to the original company. Let’s look at the technology available today to do this with SAP.

SAP

SAP claims to be the world’s largest enterprise software company. Many businesses rely on SAP for their business operations. This includes financials, human resources, manufacturing, and sales and distribution. The major value offered by SAP is the data schema and business rules to support the application.

By Web-enabling SAP companies leverage their existing technology investment. They can extend the reach of their business operations to their customers and partners. The result is a saving for everyone involved in the business pipeline.

WroxShop wants to integrate with their ERP so a customer’s sales order is automatically generated the instant they order it from the WroxShop web site. It turns out they have a couple of choices: webMethod's B2B Integration Server and Microsoft's BizTalk Server.

WebMethod’s B2B Integration Server

WebMethod’s B2B Integration Server uses XML to automate the exchange of data between application and legacy data sources. In particular they have a plug-in to interface with SAP R/3.

From the webMethod’s web site:

At the heart of webMethods B2B for R/3 are server extensions that map SAP BAPIs (Business Application Programming Interfaces) to and from XML document structures. All SAP functionality accessible via BAPIs can be made available to business partners over the Internet as secure XML-based services. This XML service layer makes R/3 functionality available to other applications either within the organization or at other partners over the Internet. The other applications do not need any understanding of R/3 BAPIs or internal data structures.

webMethods B2B for R/3 allows for bi-directional communication to and from R/3 BAPIs. All SAP functionality exposed as BAPIs are accessible using the XML-based service architecture. Furthermore, a single SAP function call can instantly invoke application services published by webMethods B2B for R/3, making the information of the Web available from an R/3 system.

SAP has OEMed B2B Integration Server as the business connector so we should be seeing XML connectivity to SAP out of the box in future releases of R/3.

BizTalk AIC for SAP

Microsoft’s BizTalk Server has an extensible framework that facilitates application integration. For example, BizTalk Server provides an Application Integration Connector (AIC) that uses DCOM to communicate with the SAP R/3 application.

Application Server to Supplier

XML-enabling an ERP system is the first step towards true business to business E-commerce. The next step is defining the XML applications that will be used between different ERP systems. Specific DTDs are being defined so industries will have a common set to choose from. One example of this kind of initiative is Commerce XML.

Commerce XML (cXML)

The vision behind cXML is to provide a simple, XML based protocol between entities wishing to engage in Business-to-Business eCommerce transactions over the Internet. Specifically, it is a set of DTDs for request/response messaging. These messages provide support for:

Ø Purchase Orders

Ø Charge Orders

Ø Acknowledgements

Ø Status updating

Ø Shipment notifications

Ø Payment transactions

The cXML DTDs will be migrated to XML-Schemas so they can be used in the BizTalk framework.

WroxShop is going to use cXML to place orders with their suppliers.

Creating a Document Definition

You might be in the fortunate, or not so fortunate, situation of being the first person to explore doing a particular type of transaction using XML. For instance, WroxShop needs to create a new document definition for the submission of warranty claims. In this case, you will have to define and publish the document definition. You have the choice of creating a DTD or an XML Schema to work within the BizTalk Framework. Let’s look at the BizTalk Framework.

BizTalk Framework

The BizTalk framework offers guidelines for preparing a document definition. A document definition can be submitted to the biztalk.org web site. It will be validated at that point to see that is conforms to the BizTalk Framework. If so it will then be published to be used by the general public.

The BizTalk Framework provides a design guide for implementing a document definition. The key areas it recommends are:

Ø Define your schemas using XML-Data

Ø Use BizTalk Framework Tags

Ø Document and Classify your schema

XML.Org

If you have an XML vocabulary you want to publish, XML.org is a good place to start. The purpose of the organization is “serve as a reference repository for specific XML standards such as vocabularies, DTDs, schemas, and namespaces”. XML.org is operated by OASIS (Organization for the Advancement of Structured Information Standards).