title: conditional include in asciidoc
body: <p>I am using Spring RestDoc together with AsciiDoc to describe my rest api. RestDoc generates different files depending if there are request parameters described / response fields etc. I would like to have one template conditionally including whatever file exists.</p>
  
  <p>something like this:</p>
  
  <pre><code>Request:
  
  include::{reqresPath}/http-request.adoc[]
  
  Response:
  include::{reqresPath}/http-response.adoc[]
  
  Parameters:
  ifeval::[{{reqresPath}/request-parameters.adoc}.exists]
    include::{reqresPath}/request-parameters.adoc[]
  endif::[]
  ifeval::[{{reqresPath}/request-parameters.adoc}.exists]
    include::{reqresPath}/request-parameters.adoc[]
  endif::[]
  </code></pre>
  
  <p>or at least exclude warnings in case of a missing file. But I could not figure out how to suppress these.</p>