Developer Transformation Guide > Web Service Consumer Transformation > Web Service Consumer Transformation Overview

Web Service Consumer Transformation Overview

The Web Service Consumer transformation connects to a web service as a web service client to access or transform data. The Web Service Consumer transformation is a multiple-group transformation.

A web service uses open standards, such as SOAP, WSDL, and XML. SOAP is the communications protocol for web services. The web service client request and the web service response are SOAP messages. A WSDL is an XML schema that describes the protocols, formats, and signatures of the web service operations.

Web service operations include requests for information, requests to update data, or requests to perform tasks. For example, the Web Service Consumer transformation sends a SOAP request to run a web service operation called getCustomerOrders. The transformation passes a customer ID in the request. The web service retrieves the customer and order information. The web service returns the information to the transformation in a SOAP response.

The Web Service Consumer transformation connects to a web service using an endpoint URL defined in the WSDL, in a web services connection, or in an endpoint URL input port. You enable security for web services in a web services connection.

SOAP Messages

The Web Service Consumer transformation uses Simple Object Access Protocol (SOAP) to exchange information with the web services provider and to request web services. SOAP defines the format for web service request and response messages.

When you transform data with a Web Service Consumer transformation, the transformation generates a SOAP request and connects to the web service. The transformation connects to the web service using an endpoint URL defined in the WSDL object, in a web services connection, or in an endpoint URL input port. The SOAP request contains the information that the web service requires to run the requested operation. The web service operation returns data to the transformation in a SOAP response. The transformation maps data from the SOAP response and returns the data in output ports.

The Web Service Consumer transformation encodes the SOAP message headers in ISO-8859-1.

The transformation can process SOAP messages with document/literal encoding. The document/literal style requires an XML schema to describe the SOAP message. SOAP messages are formed from the XML. When a SOAP message contains multiple-occurring elements, the groups of elements form levels in the XML hierarchy. The groups are related when one level is nested within another.

A SOAP request message can contain hierarchical data. For example, the Web Service Consumer transformation sends a request to add customer orders to a sales database. The transformation passes two groups of data in a SOAP request message. One group contains a customer ID and name, and the other group contains order information. The order information occurs multiple times.

A SOAP response message can contain hierarchical data. For example, the Web Service Consumer transformation generates a SOAP request for customer orders. The web service returns an order header and multiple-occurring order detail elements in the SOAP response.

WSDL Files

A WSDL file contains a description of the data to be passed to the web service so that the sender and the receiver understand the data to exchange. You must import a WSDL file to the repository before you can create a Web Service Consumer transformation.

The WSDL describes the operations to perform on the data and a binding to a protocol or transport, so that the web service consumer can send the request message in the correct format. The WSDL describes the network address to connect to the web service.

The WSDL includes information about how to encode SOAP request and response messages. SOAP encoding determines the format of the SOAP message body. It describes the format for request and response messages that the web service uses to communicate to the web service consumer. Web service developers can use a variety of toolkits to create web services. Toolkits support different ways of encoding SOAP messages.

The Web Service Consumer transformation supports the document/literal SOAP encoding style. You can use WSDL 1.1 with the Web Service Consumer transformation. You cannot use WSDL attachments such as MIME, DIME, and MTOM messages.

Operations

A web service contains an operation for each action supported by the web service.

For example, a web service can have an operation named getcustomerid that receives a customer name and responds with the customer details. The operation input includes an element for the customer name. The operation output includes elements for customer details based on the customer name.

When you configure a Web Service Consumer transformation, you define how the transformation maps data to the operation input and how the transformation maps data from the operation output. You configure the following information in the transformation:

Input mapping: Define how to map the transformation input ports to the web service operation input nodes. The operation input defines the elements in the SOAP request for the operation.
Output mapping: Define how to map the web service operation output nodes to the transformation output ports. The operation output defines the elements in a SOAP response for the operation.

Web Service Security

You enable security for web services in a web services connection. You can configure the following types of security:

Web Service Security: The Data Integration Service can include a web service security header when it sends a SOAP request to the web service provider. The web service security header contains authentication information so the web service provider can authenticate the Data Integration Service.; You can use the following types of web service security in a web services connection:

Transport layer security: Security implemented on top of the transport layer (TCP layer) of TCP/IP using Secure Sockets Layer (SSL). Web services use Hypertext Transfer Protocol over SSL (HTTPS) as a web address for secure message transport. Web Service Consumer transformations can use TLS 1.2, TLS 1.1, or TLS 1.0. You can use the following authentication with transport layer security: HTTP authentication, proxy server authentication, and SSL certificates.
SSL authentication: You can use SSL authentication when you connect through the HTTPS protocol.; You can use the following types of SSL authentication:

HTTP authentication: You can use HTTP authentication when you connect through the HTTP protocol.; You can use the following HTTP authentication methods: