Add render macro to kemal core to have dynamic rendering mechanism. It actually binds built-in ecr parser to the Kemal as a macro.

spec/asset/hello.ecr

@@ -0,0 +1 @@
+Hello <%= env.params["name"] %>

spec/view_spec.cr

@@ -0,0 +1,13 @@
+require "./spec_helper"
+
+describe "Views" do
+  it "renders file" do
+    kemal = Kemal::Handler.new
+    kemal.add_route "GET", "/view/:name" do |env|
+      render "spec/asset/hello.ecr"
+    end
+    request = HTTP::Request.new("GET", "/view/world")
+    response = kemal.call(request)
+    response.body.should contain("Hello world")
+  end
+end