A Dynamic Transformation control provides a business process with the ability to dynamically select which transformation is invoked at run time.

A Dynamic Transformation control provides a business process with the ability to dynamically select and implement a transformation during run time. Specifically, it provides the ability to choose which XQuery, XSLT, or MFL file is invoked at run time. For example, if you have an integration hub that receives documents from different regional offices, you can use the Dynamic Transformation control to perform different transformations based on the area code of each regional office.

Topics Included in This Section

Overview: Dynamic Transformation Control

Creating a New Dynamic Transformation Control

Overview: Dynamic Transformation Control

A Dynamic Transformation control provides a business process with the ability to dynamically select which transformation is invoked at run time.

This control provides eight base methods and the ability to create custom methods for selecting which file to use for your transformation. You can base the selection on the method context or the content of the message. The dynamic selection of the transformation is done through setting URIs that point to different transformation files. The available types of transformations are as follows:

The Dynamic Transformation control uses transformations that have already been created, such as those created with the Transformation control. Be sure to test your transformation before creating a Dynamic Transformation control. To learn more about Transformation controls and transforming data, see Transformation Data Using XQuery.

Before calling a Dynamic Transformation control, in the process of developing your business process, you need to design the logic that determines which transformation to run. You can use a Decision node or other controls, such as the Database or XML Metadata controls, for this purpose.

Dynamic XQuery Transformation

Method with HashMap. Use this base method to select the transformation when the argument type and values are unknown at design time. This method requires that you provide a HashMap with the variables and the types along with the XQuery file. The XML documents can be either typed or untyped. Use a Perform node to specify these values, as shown in the following:

public void perform() { 
_map = new java.util.HashMap(); 
// The name should be the variable Name and the value the Document passed 
_map.add("CustomerDoc",customerDoc); 
}

Method with XmlObjects In XmlObjects Out. Use this base method to choose which XQuery to use for transforming untyped XML documents to untyped XML documents.
Custom method. When you know the input types (arguments) at design time, you can define a custom method to choose which XQuery file to use for typed, untyped, or Java class documents.

Dynamic XSLT Transformations

Method with HashMap. Use this base method to select the transformation when the argument type and values are unknown at design time. This method requires that you provide a HashMap with the variables and the types along with the XSL file. The XML documents can be either typed or untyped. Use a Perform node to specify these values. See Dynamic XQuery Transformation.
Custom method. When you know the input types (arguments) at design time, you can define a custom method to choose which XSL file to use for untyped documents (XmlObject).

MFL—Five base methods provide the ability to select which MFL is invoked at run time based on the message context. Both binary-to-XML and XML-to-binary transformations are supported.

Related Topics

Creating a New Dynamic Transformation Control

For information on where to add control instances in a business process, see "Adding Control Nodes to Your Business Process" in Using Integration Controls.

To Create a New Dynamic Transformation Control

Open your WebLogic Integration application in BEA Workshop for WebLogic Platform.
In the Package Explorer pane, double-click the business process (Process.java file) to which you want to add the Dynamic Transformation control. The business process is displayed in the Design View.
On the Data Palette, in the Controls tab, click AddIntegration Controls to display a list of integration controls that represent the resources with which your business process can interact.

Note:

If the Data Palette is not visible, from the menu bar, click Window

Show View

Data Palette.

Select Dynamic Transformation.

The Insert Control: Dynamic Transformation dialog box is displayed (see Figure 4-1).

Figure 4-1 Insert Control: Dynamic Transformation

Insert Control: Dynamic Transformation

In the Insert Control: Dynamic Transformation dialog box enter the following details:

In the Field Name, type the variable name used to access the new Dynamic Transformation control instance from your business process. The name you enter must be a valid Java identifier.
In the Insertion point: from the drop-down list select the insertion node, you want to add the control.
Decide whether you want to make this a control factory by selecting or clearing the Make this a control factory that can create multiple instances at runtime check box. For more information about control factories, see Control Factories: Managing Collections of Controls.
Click Next.

The Create Control dialog-box appears.

In the Create Control dialog box enter the following details:

In the Name field, type the name of your new control file.
Decide whether you want to add comments as configured in the properties of the current project and select or clear the Generate comments check box.
Click Finish.

A new Dynamic Transformation control and an instance of it are created and the instance of the control is displayed on the Controls tab of the Data Palette. The new file is displayed in the Package Explorer pane in BEA Workshop for WebLogic Platform. (You can double-click any control file to view or edit it in the Source view.)

To display the base methods provided on a Dynamic Transformation control, expand the control instance by clicking the + beside its name on the Data Palette (see Figure 4-2).

Figure 4-2 Control Instances

Control Instances

After you create an instance of the Dynamic Transformation control in your business process, you can do the following:

Design the interaction of the business process with the Dynamic Transformation control by simply dragging and dropping the base methods from the Data Palette onto the Design view at the point in your business process at which you want to design the interaction. To learn more, see Using the Base Methods in the Dynamic Transformation Control.
View and edit the properties of the control type or the instance of that control type in the Properties pane. The control type is represented as a Java file in the Package Explorer pane and the instance is represented in the Data Palette. To learn how to use the Properties pane for specifying properties for control types versus control instances, see Setting Control Properties.

Using a Dynamic Transformation Control

This section describes ways to use a Dynamic Transformation control. It contains the following topic:

Using the Base Methods in the Dynamic Transformation Control

Once you have created the Dynamic Transformation control, you can add a control instance to your business process and invoke its base methods from within your application.

XmlObject[] performXQuery(String xQueryName,HashMap inputList)

Executes an XQuery and the arguments that it operates on based on message context.

XmlObject performXQueryOnXmlObject(String xQueryName,XmlObject inputDoc,String varName)

Executes an XQuery that takes an XmlObject in and XmlObject out.

XmlObject performXSLT(String xslTemplate,XmlObject source,HashMap inputList)

Executes an XSLT and the arguments that it operates on based on message context.

XmlObject convertBytesToXML(byte[] data,String mflUrl)

Executes MFL transformations.

XmlObject convertInputStreamToXML(InputStream iStream,String mflUrl)

Executes MFL transformations.

XmlObject convertRawDataToXML(RawData rawData, String mflUrl)

Executes MFL transformations.

byte[] convertXmlToBytes(XmlObject xmlObject,String mflURL)

Executes MFL transformations from XML data to non-XML data.

RawData convertXmlToRawData(XmlObject xmlObject,String mflURL)

Executes MFL transformations from XML data to non-XML data.

The @DynamicTransformationControl.Ddtf, @DynamicTransformationControl.Xquery, @DynamicTransformationControl.Xsl annotations control the behavior of these methods. Additional information is also available in the Interface DynamicTransformation.

Using Integration Controls

Dynamic Transformation Control

Topics Included in This Section

Overview: Dynamic Transformation Control

Creating a New Dynamic Transformation Control

Overview: Dynamic Transformation Control

Related Topics

Creating a New Dynamic Transformation Control

To Create a New Dynamic Transformation Control

Using a Dynamic Transformation Control

Using the Base Methods in the Dynamic Transformation Control

Related Topics

Example: Dynamic Transformation Control