Programatically render template area in Magnolia CMS - rendering

Question

I search for rendering specific content in Magnolia like components with Render Engine So I found this topic on stackoverflow : Programatically render template area in Magnolia CMS
My question is about the structure of the following classes : FilteringAppendableWrapper and
FakeResponse : used to put fake Http Response in the AppendableFilteringResponseOutputProvider
Thanks for any help.

Answer 1

What about it do yo want to ask? Why he didn't use the real response? Because he was faking whole (web) request to a page too and then getting output from his "FakeResponse" and adding it to json array to fill in body of the response of a request that came over REST.
Personally, I think such solution is overkill for the job and if I had to do the same, I would probably simply register variation template for a component or whole page and when requesting page w/ e.g. .ajax extension I would have my variation to kick in and rendered whole page (or area or component) as a json array.
HTH,
Jan

Answer 2

There is no need for fake response. This simple code work well :
Session session = MgnlContext.getJCRSession("website");
Node content = session.getNode("/protoTest/content/01");
componentDefinition = templateDefinitionAssignment.getAssignedTemplateDefinition(content);
OutputStream outputStream = new ByteArrayOutputStream();
OutputStreamWriter writer = new OutputStreamWriter(outputStream);
appendable = new AppendableOnlyOutputProvider(writer);
renderingEngine.render(content, componentDefinition, new HashMap<String, Object>(), appendable);
((Writer) appendable.getAppendable()).flush();
System.out.println(outputStream.toString());