Ability to register a view engine per group of routes or for the current a chain of handlers

Example at: https://github.com/kataras/iris/tree/master/_examples/view/context-view-engine

_examples/view/context-view-engine/views/public/500.html

@@ -0,0 +1,12 @@
+<!-- You can define more than one block.
+The default one is "content" which should be the main template's body.
+So, even if it's missing (see index.html), it's added automatically by the view engine.
+When you need to define more than one block, you have to be more specific:
+-->
+{{ define "content" }}
+<h1>Internal Server Error</h1>
+{{ end }}
+
+{{ define "message" }}
+<p style="color:red;">{{.Message}}</p>
+{{ end }}