extract template lookup logic, fixes #48

lib/sinatra/base.rb

@@ -460,6 +460,15 @@ module Sinatra
       render :slim, template, options, locals
     end
 
+    # Calls the given block for every possible template file in views,
+    # named name.ext, where ext is registered on engine.
+    def find_template(views, name, engine)
+      Tilt.mappings.each do |ext, klass|
+        next unless klass == engine
+        yield ::File.join(views, "#{name}.#{ext}")
+      end
+    end
+
   private
     # logic shared between builder and nokogiri
     def render_ruby(engine, template, options={}, locals={}, &block)
@@ -516,10 +525,12 @@ module Sinatra
             template.new(path, line.to_i, options) { body }
           else
             found = false
-            Tilt.mappings.each do |ext, klass|
-              next unless klass == template
-              path = ::File.join(views, "#{data}.#{ext}")
-              break if found = File.exists?(path)
+            find_template(views, data, template) do |file|
+              path ||= file # keep the initial path rather than the last one
+              if found = File.exists?(file)
+                path = file
+                break
+              end
             end
             throw :layout_missing if eat_errors and not found
             template.new(path, 1, options)

test/templates_test.rb

@@ -247,6 +247,25 @@ class TemplatesTest < Test::Unit::TestCase
     assert ok?
     assert_equal 'Hello World!', body
   end
+
+  it "is possible to use custom logic for finding template files" do
+    mock_app do
+      set :views, ["a", "b"].map { |d| File.dirname(__FILE__) + '/views/' + d }
+      def find_template(views, name, engine, &block)
+        Array(views).each { |v| super(v, name, engine, &block) }
+      end
+
+      get('/:name') do
+        render :str, params[:name].to_sym
+      end
+    end
+
+    get '/in_a'
+    assert_body 'Gimme an A!'
+
+    get '/in_b'
+    assert_body 'Gimme a B!'
+  end
 end
 
 # __END__ : this is not the real end of the script.

test/views/a/in_a.str

@@ -0,0 +1 @@
+Gimme an A!

test/views/b/in_b.str

@@ -0,0 +1 @@
+Gimme a B!