Calling SOAP Web Services from IBM App Connect flows (Part 1)

Introduction

IBM App Connect has added the ability to import SOAP web services to a user’s catalog and invoke them from a flow. This allows users to expose and call existing web service business applications that are running in their enterprise and connect them with any of the other applications App Connect supports.

Adding a web service to your catalog

In order to add a new web service to a catalog all you need is a valid WSDL document which represents a SOAP service. This WSDL could be in the form of a .wsdl file, a URL to a WSDL file, or a ZIP file containing a combination of WSDL and XSD files. (There are some restrictions; see here for details)

Before a web service can be called in a flow it needs to be imported into your catalog and connected to. This is a one time step and will allow the web service to be invoked in multiple flows.

1. In the App Connect UI, go to the Catalog > APIs page, then click the Add your API or web service now link.
   
   
2. Either add the WSDL or ZIP file, or enter the URL pointing to the publicly available WSDL, enter a name and description then click Add API.
   
   
3. The web service will appear in the catalog. In order to use it in a flow you’ll need to connect to it first. This will give you the chance to enter some authentication details if required or to override the SOAP address that is currently specified in the WSDL. Enter any relevant fields and click Connect.
   
   

Using the web service in your flow

At this point the web service can be used in a flow and should appear in the same way as any other connector.

1. From a flow, when adding a target action, select the APIs tab to display a list of APIs and web services that you are currently connected to. You can expand the details to see available operations which are available from the WSDL. Select the operation you wish to invoke.
   
   
2. Input properties can be populated either manually for from the output of earlier nodes in the flow.
3. Response properties can be used by subsequent nodes in the flow. The both successful responses and any possible failure details
   are included in the response, which allows the flow to act on them accordingly.
   
   

Summary

This blog post has shown to how invoke Web Services from within your IBM App Connect flows, opening up more opportunities to connect and integrate with existing enterprise applications in a cloud environment.