Marvin Oßwald filed a really interesting issue: https://issues.jboss.org/browse/APIMAN-1300 In short, if we imagine a policy chain like this: [CORS, PolicyA, PolicyB] Even if PolicyB emits a failure, then the CORS policy would likely still want to be able to process the PolicyFailure to add the relevant headers (otherwise a SPA type app like Angular would break). This seems like a valid use-case. Ideally I'd like to tackle this without breaking any existing interfaces. A couple of quick ideas: * Add a new interface that policies like CORS could implement that indicates it wants to do this kind of processing. E.g. IFailureProcessor or similar with a simple method signature like #process(PolicyFailure failureToModify). * An annotation: essentially the same as above, but with a @WhateverWeCallIt annotation on the method that does the processing.

As I had no negative feedback, this has been merged (along with tests). It should be in the next release. On 4 July 2018 at 20:44, Marc Savy <marc.savy(a)redhat.com&gt; wrote: > Hi, > > I have a prototype of this available for people to try (forgive any > scrappiness, this will be tidied before the final version is merged): > > https://github.com/apiman/apiman/pull/686/files > > It works as follows: > > Let's imagine our policy chain again. > [CORS, PolicyA, PolicyB] > > * If a policy failure occurs in the *request* chain, the entire > response chain will be executed (in the usual reverse order) with > #processFailure > > Imagine PolicyA throws a failure on the request leg, then each of the > policies will have a chance to modify the failure object in the > following order: > [PolicyB, PolicyA, CORS] > > * If a policy failure occurs during the *response* chain, then only > the remaining policies will have a chance to process the failure. > > This seemed like the most sensible/practical design to me -- happy to > hear feedback, though. > > Here's an example of a policy using this proposed functionality: > https://gist.github.com/msavy/b872efa7f08929d19a420ea68ec3f584 > > > Regards, > Marc > > On 12 April 2018 at 19:42, Marc Savy <marc.savy(a)redhat.com&gt; wrote: >> Marvin Oßwald filed a really interesting issue: >> https://issues.jboss.org/browse/APIMAN-1300 >> >> In short, if we imagine a policy chain like this: >> >> [CORS, PolicyA, PolicyB] >> >> Even if PolicyB emits a failure, then the CORS policy would likely >> still want to be able to process the PolicyFailure to add the relevant >> headers (otherwise a SPA type app like Angular would break). >> >> This seems like a valid use-case. >> >> Ideally I'd like to tackle this without breaking any existing interfaces. >> >> A couple of quick ideas: >> >> * Add a new interface that policies like CORS could implement that >> indicates it wants to do this kind of processing. E.g. >> IFailureProcessor or similar with a simple method signature like >> #process(PolicyFailure failureToModify). >> >> * An annotation: essentially the same as above, but with a >> @WhateverWeCallIt annotation on the method that does the processing.