How to trigger an error in a WSO2 sequence? - error-handling

Question

I would like to create a input sequence where I check a param with a switch mediator. If the value of the param does not correspond to a specific string, then an error should be thrown and move the flow in the Fault sequence.
For example, I created this sequence:
<sequence name="testEquivalence" trace="disable" xmlns="http://ws.apache.org/ns/synapse">
<switch source="$ctx:uri.var.myParam">
<case regex="hello">
<log description="DISPLAY" level="full">
<property name="value" value="RIGHT VALUE FOR THE PARAM myParam"/>
</case>
<default>
<log description="FAULT" level="full">
<property name="FAULT" value="WRONG VALUE FOR THE PARAM myParam"/>
</log>
<makefault version="pox">
<reason value="Wrong value"/>
<detail expression="'Wrong value. Try with hello.'"/>
</makefault>
</default>
</switch>
</sequence>
As you can see, I want to display a log saying "RIGHT VALUE FOR THE PARAM myParam" if it is OK. Or, I would like to display a log and then stop the process in the default part to pass in the Fault sequence.
However, I created a makefault mediator to "modelize" my fault but is it possible to replace it by something more... executive to stop the process and redirect the flow in the Fault sequence like if an exception was thrown?

Answer 1

There is no way to throw an exception in WSO2 ESB/EI. Generally after creating a SOAPFault you want to return this to the caller of the service. A Solution is to use the Response Mediator after the Fault mediator:
<sequence name="testEquivalence" trace="disable" xmlns="http://ws.apache.org/ns/synapse">
<switch source="$ctx:uri.var.myParam">
<case regex="hello">
<log description="DISPLAY" level="full">
<property name="value" value="RIGHT VALUE FOR THE PARAM myParam"/>
</case>
<default>
<log description="FAULT" level="full">
<property name="FAULT" value="WRONG VALUE FOR THE PARAM myParam"/>
</log>
<makefault version="pox">
<reason value="Wrong value"/>
<detail expression="'Wrong value. Try with hello.'"/>
</makefault>
<respond/>
</default>
</switch>
</sequence>