Friday, January 25, 2013

How to read in REST parameters in the Axway Vordel API Gateway

The Axway Vordel API Gateway allows you to read in REST API parameters from an incoming request, and then use these parameters for a variety of purposes, for example to pass them into a SOAP message, or use them to call a method of a Java class via the Scripting Filter. 

The key to this is the "Extract REST Request Attributes" filter. If I type in "REST" into the search box on Policy Studio, it helpfully narrows down the filter list to just the filters related to REST. 


When I drag in an "Extract REST Request Attributes" filter, I see this configuration below. As you can see, you can have the API Gateway read API parameters from the querystring or from HTTP POST parameters. 


Once I place this filter into a policy which is mapped to a REST endpoint on the API Gateway (e.g. a relative path), I can then access the REST parameters in other filters. 

Let's say a parameter is passed like this:

https://apiserver.companyx.com/orders/purchaseorder?product=1234&customerID=AcmeInc

I can now access the content of the "customerID" parameter like this:

 ${http.querystring.customerID}