How to throw Soap Fault manually in mule - soap

Question

I'm face with a situation where we cannot use schema to validate incoming request (basically schema is there but it accepts any String in request, wsdl designers have their own reasons to do that to accept request from different sources and flexibility). But when the request is received, I validate that the child element of request wrapper is what we expect (using XPath for that). Now if the child element is not what expected, I'd like to throw Soap Fault with Client code and may be include error message that schema validation failed, request doesn't contain valid element.
I'm using Mule 3.3 and doing my XPath validation in <choice> element and I want to throw exception in <otherwise> block.
Is there a way to throw Soap Fault manually in mule flow and
How to add custom fault string. I'm not sure if an outInterceptor will solve the purpose as I'm not using schemaValidation attribute of <cxf:proxyService>.
Here is part of my flow
<http:inbound-endpoint address="${service.address}" exchange-pattern="request-response">
<cxf:proxy-service wsdlLocation="classpath:service.wsdl" namespace="http://company.com/services/service" service="CompanyService" />
</http:inbound-endpoint>
<choice>
<when>.....</when>
<otherwise><!-- Here I want to throw Soap Fault ---></otherwise>
</choice>
<catch-exception-strategy>
<flow-ref name="generateErrorResponse" />
</catch-exception-strategy>

Answer 1

Since you are using a cxf:proxy-service you have complete control on the response. For example, if you add the following in your otherwise block, you'll be able to create whatever SOAP fault you want:
<expression-component><![CDATA[
message.payload = '<soap:Fault xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">'
+ '<faultcode>A code</faultcode><faultstring>A string</faultstring>'
+ '</soap:Fault>';
]]></expression-component>