Straight-Through Data Transformation Example

Use Case

The DEF Corporation's intranet has a Web-based online store through which employees can purchase the company's products. The store's XFORMS-based Web interface registers the order by sending an XML document containing the order details to an asynchronous message queue, which is serviced by a workflow management system. Each incoming message triggers a new workflow instance that retrieves additional information about the employee (by calling a predefined procedure). The workflow then merges the extra information into the XML document by applying an XSL transform. It then submits the transformed order for fulfillment by invoking the Sales Order System's Web Service interface.

Interfaces

Input Document schema

The input document is a string containing an XML document that conforms to the following XML Schema:

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    elementFormDefault="qualified"
    targetNamespace="http://www.def.com/2004/intranet/webstore">
    <xsd:element name="web-order">
        <xsd:complexType>
            <xsd:sequence>
                <xsd:element name="header">
                    <xsd:complexType>
                        <xsd:sequence>
                            <xsd:element name="userid" type="xsd:NMTOKEN"/>
                            <xsd:element name="datetime" type="xsd:dateTime"/>
                        </xsd:sequence>
                    </xsd:complexType>
                </xsd:element>
                <xsd:element name="items">
                    <xsd:complexType>
                        <xsd:sequence>
                            <xsd:element maxOccurs="unbounded" name="item">
                                <xsd:complexType>
                                    <xsd:sequence>
                                        <xsd:element name="sku" type="xsd:string"/>
                                        <xsd:element name="qty" type="xsd:integer"/>
                                    </xsd:sequence>
                                </xsd:complexType>
                            </xsd:element>
                        </xsd:sequence>
                    </xsd:complexType>
                </xsd:element>
            </xsd:sequence>
        </xsd:complexType>
    </xsd:element>
</xsd:schema>

Functions available from scripting language

Map createMap(IN STRING key, IN STRING value)

Procedures

lookupAccount(IN STRING userId, OUT STRING accountNumber)
transform(IN Document input, OUT Document output, IN STRING transformURI, IN Map parms)

XSL transform

<?xml version="1.0" encoding="UTF-8"?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"
	xmlns:in="http://www.def.com/2004/intranet/webstore"
	xmlns="http://www.def.com/2004/pub/sales">
	
	<xsl:output method="xml"/>

	<!-- The user's account number, passed in as a parameter. -->
	<xsl:param name="account-number"/>

	<xsl:template match="in:order">
		<xsl:element name="sales-order">
			<xsl:apply-templates/>
		</xsl:element>
	</xsl:template>

	<xsl:template match="in:userid">
		<xsl:element name="account-number">
			<xsl:value-of select="$account-number" disable-output-escaping="yes"/>
		</xsl:element>
	</xsl:template>

	<xsl:template match="*">
		<xsl:element name="{local-name(.)}">
			<xsl:apply-templates/>
		</xsl:element>
	</xsl:template>

</xsl:transform>

Web Service Description

The Sales Order Processing system has a Web Service interface defined by the following WSDL:

<?xml version="1.0" encoding="UTF-8"?>
    
<wsdl:definitions targetNamespace="http://www.def.com/2004/pub/sales"
    
 xmlns:impl="http://www.def.com/2004/pub/sales"

    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"

    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/">
 <wsdl:types>
    
 <xsd:schema targetNamespace="http://www.def.com/2004/pub/sales"

    xmlns:xsd="http://www.w3.org/2001/XMLSchema"

    elementFormDefault="qualified">

 <xsd:element
    name="sales-order">
 <xsd:complexType>
 <xsd:sequence>
    
 <xsd:element name="header">
 <xsd:complexType>
 <xsd:sequence>
    
 <xsd:element name="account-number" type="xsd:string"/>
 <xsd:element
    name="datetime" type="xsd:dateTime"/>
 </xsd:sequence>
 </xsd:complexType>
    
 </xsd:element>
 <xsd:element name="items">
 <xsd:complexType>
    
 <xsd:sequence>
 <xsd:element maxOccurs="unbounded"
    name="item">
 <xsd:complexType>
 <xsd:sequence>

    <xsd:element name="sku" type="xsd:string"/>
 <xsd:element
    name="qty" type="xsd:integer"/>
 </xsd:sequence>
 </xsd:complexType>
    
 </xsd:element>
 </xsd:sequence>
 </xsd:complexType>
    
 </xsd:element>
 </xsd:sequence>
 </xsd:complexType>
    
 </xsd:element>
 </xsd:schema>
 </wsdl:types>
    

 <wsdl:message name="raiseOrderRequest">
 <wsdl:part
    name="order" element="impl:sales-order"/>
 </wsdl:message>

    
 <wsdl:portType name="SalesOrdersPortType">
 <wsdl:operation
    name="raiseOrder" parameterOrder="order">
 <wsdl:input
    name="raiseOrderRequest" message="impl:raiseOrderRequest"/>
 </wsdl:operation>
    
 </wsdl:portType>

 <wsdl:binding
    name="SalesOrdersPortSoapBinding" type="impl:SalesOrdersPortType">

    <soap:binding style="document"
    transport="http://schemas.xmlsoap.org/soap/http"/>
 <wsdl:operation
    name="raiseOrder">
 <soap:operation
    soapAction="http://www.def.com/sales/raiseOrder"/>
 <wsdl:input
    name="raiseOrderRequest">
 <soap:body
    namespace="http://www.def.com/2004/pub/sales" use="literal"/>
 </wsdl:input>
    
 </wsdl:operation>
 </wsdl:binding>

 <wsdl:service
    name="SalesOrders">
 <wsdl:port name="SalesOrdersPort"
    binding="impl:SalesOrdersPortSoapBinding">
 <soap:address

    location="http://localhost:8080/obeexamples/services/SalesOrders"/>

    </wsdl:port>
 </wsdl:service>
</wsdl:definitions>

Hints

Incorporate the input schema into the XPDL as a user-defined <xpdl:SchemaType> .
Declare a STRING accountNumber <xpdl:DataField> to hold the result of lookupAccount().
Assume the XSL transform is available through the URI web-sales-order.xsl.
Create user-defined types:

Document ::= java:org.w3c.dom.Document
Map ::= java:java.util.Map

Assume that the workflow can access the WSDL document by appending ?wsdl to the Web Service's SOAP endpoint address.
Declare the Web Service as an <xpdl:Application> defined by an <xpdl:ExternalReference>:

location = WSDL URI
namespace = target namespace URI
xref = WSDL operation name

The workflow should run 'straight through' to completion in a single transaction and should not require any human intervention.

Solution

Process Model Description

The workflow is triggered by the DEFWebOrderReceived event (defined in $OBE_HOME/examples/config/BasicApplicationEvent.xml). Notice the <xpdl:ExtendedAttribute name="obe.Event"> element attached to the <WorkflowProcess> below: see how it initializes the mandatory¹ order process attribute from the event by specifying it as an OUT parameter of the event.
The Lookup Account activity invokes the lookupAccount() procedure. It extracts the User ID from the order document with the XPath expression string($order/defws:web-order/defws:header/defws:userid) and passes it to the procedure as an IN parameter. The accountNum process attribute is set from the procedure's result by specifying it as an OUT parameter.
The Transform Data activity invokes the obe.transform procedure, passing a reference to the XSL transform shown above. The transform resides in the web-sales-order.xsl file stored in the ResourceRepository (see $OBE_HOME/examples/config/BasicResourceRepository.xml and the $OBE_HOME/examples/config/resources directory). The transformed document is stored in the salesOrder process attribute (once again, the receiving attribute is passed as an OUT parameter).
The Submit Order activity passes the sales order to the submitOrder Web Service, which is described by the submitOrder tool with an <xpdl:ExternalReference> to the Web Service endpoint URL: http://localhost:8080/obeexamples/services/SalesOrdersPort?wsdl

XPDL Process Model

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://www.wfmc.org/2002/XPDL1.0" xmlns:xpdl="http://www.wfmc.org/2002/XPDL1.0"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:obe="http://obe.sourceforge.net/2005/OBE1.0" xmlns:defws="http://www.def.com/2004/intranet/webstore"
    Id="eai" Name="EAI Data Transformation" xsi:schemaLocation="http://www.wfmc.org/2002/XPDL1.0 xpdl-1.0.xsd">
    <PackageHeader>
        <XPDLVersion>1.0</XPDLVersion>
        <Vendor>Open Business Engine</Vendor>
        <Created>2004-08-08T21:26:45+0100</Created>
    </PackageHeader>
    <RedefinableHeader PublicationStatus="UNDER_TEST"/>
    <ConformanceClass GraphConformance="NON_BLOCKED"/>
    <Script Type="text/x-xpath"/>
    <TypeDeclarations>
        <TypeDeclaration Id="WebOrder" Name="Web Store Order">
            <ExternalReference location="web-order.xsd" xref="order"
                namespace="http://www.def.com/2004/intranet/webstore"/>
            <Description>This is the order type generated by the internal Web Store portal.</Description>
        </TypeDeclaration>
        <TypeDeclaration Id="SalesOrder" Name="SalesOrder">
            <ExternalReference
                location="http://sales.def.com:8080/axis/services/OrderService?wsdl"
                xref="SalesOrderType" namespace="http://www.def.com/2004/pub/sales"/>
            <Description>This is the type of the Sales Order document accepted by the Sales Order Management system.</Description>
        </TypeDeclaration>
        <TypeDeclaration Id="Document" Name="XML Document">
            <ExternalReference location="java:org.w3c.dom.Document"/>
        </TypeDeclaration>
        <TypeDeclaration Id="Map" Name="Java Map">
            <ExternalReference location="java:java.util.Map"/>
            <Description>This type represents the Java2 Map interface.</Description>
        </TypeDeclaration>
    </TypeDeclarations>
    <WorkflowProcesses>
        <WorkflowProcess Id="eai" Name="EAI Data Transformation" AccessLevel="PRIVATE">
            <ProcessHeader DurationUnit="D">
                <Created>2004-08-08T21:28:00+0100</Created>
                <Description>
                    This workflow exemplifies straight-through processing, EAI (Enterprise Application Integration), and
                    data transformation.
                </Description>
            </ProcessHeader>
            <RedefinableHeader PublicationStatus="UNDER_TEST"/>
            <FormalParameters>
                <FormalParameter Id="order" Mode="IN">
                    <DataType>
                        <DeclaredType Id="WebOrder"/>
                    </DataType>
                </FormalParameter>
            </FormalParameters>
            <DataFields>
                <DataField Id="accountNumber" Name="Account Number">
                    <DataType>
                        <BasicType Type="STRING"/>
                    </DataType>
                    <Description>The user's internal account number.</Description>
                </DataField>
                <DataField Id="salesOrder" Name="Sales Order">
                    <DataType>
                        <DeclaredType Id="Document"/>
                    </DataType>
                </DataField>
                <DataField Id="int">
                    <DataType>
                        <BasicType Type="INTEGER"/>
                    </DataType>
                </DataField>
                <DataField Id="bool">
                    <DataType>
                        <BasicType Type="BOOLEAN"/>
                    </DataType>
                </DataField>
                <DataField Id="date">
                    <DataType>
                        <BasicType Type="DATETIME"/>
                    </DataType>
                </DataField>
            </DataFields>
            <Applications>
                <Application Id="lookupAccount" Name="Lookup Account Number">
                    <Description>Finds the internal Web Store account number for the specified employee.</Description>
                    <FormalParameters>
                        <FormalParameter Id="userID" Mode="IN">
                            <DataType>
                                <BasicType Type="STRING"/>
                            </DataType>
                            <Description>The employee's user ID.</Description>
                        </FormalParameter>
                        <FormalParameter Id="accountNumber" Mode="OUT">
                            <DataType>
                                <BasicType Type="STRING"/>
                            </DataType>
                            <Description>The employee's Web Store account number.</Description>
                        </FormalParameter>
                    </FormalParameters>
                </Application>
                <Application Id="obe.transform" Name="Transform XML Document">
                    <Description>This procedure transforms an XML document using an XSL transform.</Description>
                    <FormalParameters>
                        <FormalParameter Id="in" Mode="IN">
                            <DataType>
                                <DeclaredType Id="Document"/>
                            </DataType>
                            <Description>The input XML document, represented as a W3C DOM node.</Description>
                        </FormalParameter>
                        <FormalParameter Id="transformUri" Mode="IN">
                            <DataType>
                                <BasicType Type="STRING"/>
                            </DataType>
                            <Description>This is the URI of the XSL transform to apply</Description>
                        </FormalParameter>
                        <FormalParameter Id="parameters" Mode="IN">
                            <DataType>
                                <DeclaredType Id="Map"/>
                            </DataType>
                            <Description>A map of input parameters, keyed on name.</Description>
                        </FormalParameter>
                        <FormalParameter Id="out" Mode="OUT">
                            <DataType>
                                <DeclaredType Id="Document"/>
                            </DataType>
                            <Description>The transformed XML document, represented as a W3C DOM node.</Description>
                        </FormalParameter>
                    </FormalParameters>
                </Application>
                <Application Id="submitOrder" Name="Submit Order">
                    <Description>
                        Submits a sales order to the Web Service entry point for the Sales Order Handling System.
                    </Description>
                    <ExternalReference location="http://localhost:8080/obeexamples/services/SalesOrdersPort?wsdl"
                        xref="raiseOrder" namespace="http://www.def.com/2004/pub/sales"/>
                </Application>
            </Applications>
            <Activities>
                <Activity Id="lookupAccNum" Name="Lookup Account Number">
                    <Implementation>
                        <Tool Id="lookupAccount" Type="PROCEDURE">
                            <ActualParameters>
                                <ActualParameter>string($order/defws:web-order/defws:header/defws:userid)</ActualParameter>
                                <ActualParameter>accountNumber</ActualParameter>
                            </ActualParameters>
                            <Description>
                                Extract the user ID from the inbound document and look up that user's internal account number.
                            </Description>
                        </Tool>
                    </Implementation>
                    <StartMode>
                        <Automatic/>
                    </StartMode>
                    <FinishMode>
                        <Automatic/>
                    </FinishMode>
                    <ExtendedAttributes>
                        <ExtendedAttribute Name="ParticipantID" Value="FreeTextExpressionParticipant"/>
                        <ExtendedAttribute Name="XOffset" Value="170"/>
                        <ExtendedAttribute Name="YOffset" Value="50"/>
                        <ExtendedAttribute Name="obe.Bounds">
                            <obe:Bounds x="41" y="48" width="140" height="50"/>
                        </ExtendedAttribute>
                    </ExtendedAttributes>
                </Activity>
                <Activity Id="transform" Name="Transform Data">
                    <Implementation>
                        <Tool Id="obe.transform" Type="PROCEDURE">
                            <ActualParameters>
                                <ActualParameter>$order</ActualParameter>
                                <ActualParameter>'web-sales-order.xsl'</ActualParameter>
                                <ActualParameter>def:createMap('account-number', $accountNumber)</ActualParameter>
                                <ActualParameter>salesOrder</ActualParameter>
                            </ActualParameters>
                            <Description>
                                Transforms the order document from the web store into the format required by the
                                Sales Order Handling System.
                            </Description>
                        </Tool>
                    </Implementation>
                    <StartMode>
                        <Automatic/>
                    </StartMode>
                    <FinishMode>
                        <Automatic/>
                    </FinishMode>
                    <ExtendedAttributes>
                        <ExtendedAttribute Name="ParticipantID" Value="FreeTextExpressionParticipant"/>
                        <ExtendedAttribute Name="XOffset" Value="310"/>
                        <ExtendedAttribute Name="YOffset" Value="50"/>
                        <ExtendedAttribute Name="obe.Bounds">
                            <obe:Bounds x="287" y="49" width="140" height="50"/>
                        </ExtendedAttribute>
                    </ExtendedAttributes>
                </Activity>
                <Activity Id="submitOrder" Name="submit Order">
                    <Implementation>
                        <Tool Id="submitOrder" Type="PROCEDURE">
                            <ActualParameters>
                                <ActualParameter>$salesOrder</ActualParameter>
                            </ActualParameters>
                            <Description>
                                Invokes the Sales Order Processing System's Web Service to submit the order.
                            </Description>
                        </Tool>
                    </Implementation>
                    <StartMode>
                        <Automatic/>
                    </StartMode>
                    <FinishMode>
                        <Automatic/>
                    </FinishMode>
                    <ExtendedAttributes>
                        <ExtendedAttribute Name="ParticipantID" Value="FreeTextExpressionParticipant"/>
                        <ExtendedAttribute Name="XOffset" Value="440"/>
                        <ExtendedAttribute Name="YOffset" Value="50"/>
                        <ExtendedAttribute Name="obe.Bounds">
                            <obe:Bounds x="544" y="50" width="140" height="50"/>
                        </ExtendedAttribute>
                    </ExtendedAttributes>
                </Activity>
            </Activities>
            <Transitions>
                <Transition Id="eai_Tra2" From="lookupAccNum" To="transform" Name="Transition">
                    <ExtendedAttributes>
                        <ExtendedAttribute Name="RoutingType" Value="NOROUTING"/>
                    </ExtendedAttributes>
                </Transition>
                <Transition Id="eai_Tra3" From="transform" To="submitOrder" Name="Transition">
                    <ExtendedAttributes>
                        <ExtendedAttribute Name="RoutingType" Value="NOROUTING"/>
                    </ExtendedAttributes>
                </Transition>
            </Transitions>
            <ExtendedAttributes>
                <ExtendedAttribute Name="obe.Event">
                    <obe:Event Id="DEFWebOrderReceived">
                        <xpdl:ActualParameters>
                            <xpdl:ActualParameter>order</xpdl:ActualParameter>
                        </xpdl:ActualParameters>
                    </obe:Event>
                </ExtendedAttribute>
                <ExtendedAttribute Name="StartOfWorkflow" Value="FreeTextExpressionParticipant;lookupAccNum;60;50;NOROUTING"/>
                <ExtendedAttribute Name="EndOfWorkflow" Value="FreeTextExpressionParticipant;submitOrder;580;50;NOROUTING"/>
                <ExtendedAttribute Name="ParticipantVisualOrder" Value="FreeTextExpressionParticipant;"/>
            </ExtendedAttributes>
        </WorkflowProcess>
    </WorkflowProcesses>
    <ExtendedAttributes>
        <ExtendedAttribute Name="MadeBy" Value="JaWE"/>
        <ExtendedAttribute Name="Version" Value="1.2"/>
    </ExtendedAttributes>
</Package>

Solution Files

See the solution files under $OBE_HOME/examples:

config/processes/eai.xpdl
config/ resources/web-sales-order.xsl
config/ resources/order.xsd
config/ resources/sales-order.xsd
config/resources/sales-order.wsdl
config/BasicFunctionRepository.xml
config/BasicToolAgentFactory.xml
etc/DataTransformation/web-order1.xml
src/com/def/webstore/DEFFunctions.java
src/com/def/webstore/DEFProcedures.java

Deployment and Execution

The eai workflow supports both manual and triggered start.

Deploy the eai.xpdl package.
Start a workflow instance by either:

Instantiating an instance of the eai workflow from the Worklist client.
When prompted, uploading an XML order that conforms to the $OBE_HOME/examples/config/resources/web-order.xsd schema, such as $OBE_HOME/examples/etc/DataTransformation/ web-order1.xml.

Open a console window and navigate to the $OBE_HOME/examples/etc/DataTransformation directory.
Execute the command: send web-order1.xml

In either case, enable logging to observe in-flight process activity, or use a worklist client or the cladmin tool to probe process instances.

¹ Mandatory, because the


    order

attribute appears as a <FormalParameter> of the <WorkflowProcess>, meaning that it must be assigned a value before a newly created process instance can be started.