ruby – 无法与Middleman一起使用HAML布局

我一直无法从默认的layout.erb文件切换到Middleman中的等效layout.haml文件.我想将HAML用于我的布局,因为我正在努力熟悉它,所以我决定用HAML版本替换默认布局.不幸的是,当我用layout.haml替换layout.erb时,我收到此错误：

NoMethodError at /
undefined method `force_encoding' for nil:NilClass

Ruby    /Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in ensure in binary,line 289
Web GET localhost/

Traceback (innermost first)

/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in ensure in binary
      string.force_encoding(original_encoding)...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in binary
      string.force_encoding(original_encoding)...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in extract_magic_comment
      binary script do...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in extract_encoding
      extract_magic_comment(script) || script.encoding...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in precompiled
        template_encoding = extract_encoding(template)...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/erb.rb: in precompiled
        source,offset = super...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/erb.rb: in precompiled
        source,offset = super...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in compile_template_method
      source,offset = precompiled(locals)...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in compiled_method
        compile_template_method(locals_keys)...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in evaluate
      method = compiled_method(locals.keys)...
/Library/Ruby/Gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb: in render
      evaluate scope,locals || {},&block...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/rendering.rb: in render_individual_file
          content = template.render(context,locs,&block)...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/rendering.rb: in render_template
            content = render_individual_file(layout_path,opts,context) { content }...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/sitemap/resource.rb: in block in render
          app.render_template(source_file,blocks)...
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/notifications.rb: in instrument
          yield payload if block_given?...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/util.rb: in instrument
        ::ActiveSupport::Notifications.instrument(suffixed_name,payload,&block)...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/application.rb: in instrument
    delegate :instrument,to: ::Middleman::Util...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/sitemap/resource.rb: in instrument
      delegate :logger,:instrument,to: :app...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/sitemap/resource.rb: in render
        instrument 'render.resource',path: relative_source,destination_path: destination_path  do...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/request.rb: in process_request
            output = resource.render do...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/request.rb: in block in call!
            process_request(env,req,res)...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/request.rb: in catch
          catch(:halt) do...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/request.rb: in call!
          catch(:halt) do...
/Library/Ruby/Gems/2.0.0/gems/middleman-core-3.3.3/lib/middleman-core/core_extensions/request.rb: in call
          dup.call!(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb: in call
      to_app.call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/urlmap.rb: in block in call
        return app.call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/urlmap.rb: in each
      @mapping.each do |host,location,match,app|...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/urlmap.rb: in call
      @mapping.each do |host,app|...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/showexceptions.rb: in call
      @app.call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/head.rb: in call
    status,headers,body = @app.call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/lint.rb: in _call
      status,@body = @app.call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/lint.rb: in call
      dup._call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb: in call
      to_app.call(env)...
/Library/Ruby/Gems/2.0.0/gems/rack-1.5.2/lib/rack/handler/webrick.rb: in service
        status,body = @app.call(env)...
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/webrick/httpserver.rb: in service
      si.service(req,res)...
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/webrick/httpserver.rb: in run
          server.service(req,res)...
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/webrick/server.rb: in block in start_thread
          block ? block.call(sock) : run(sock)

layout.erb看起来像这样：

<!doctype html>
<html>
  <head>
    <meta charset="utf-8">

    <!-- Always force latest IE rendering engine or request Chrome Frame -->
    <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible">

    <!-- Use title if it's in the page YAML frontmatter -->
    <title><%= current_page.data.title || "The Middleman" %></title>

    <%= stylesheet_link_tag "normalize" %>
    <!-- <%= stylesheet_link_tag "normalize","all" %> -->
    <%= javascript_include_tag  "all" %>
  </head>

  <body class="<%= page_classes %>">
    <%= partial "header" %>
    <%= yield %>
    <%= partial "footer" %>
  </body>
</html>

layout.haml与layout.erb没有完全相同的内容,但这似乎并不重要,因为它无论如何都会中断：

!!!
%html
  %head
    %title
      = current_page.data.title || "The Middleman"
    = stylesheet_link_tag "normalize","all"
    = javascript_include_tag "all"
  %body
    = partial "header"
    = yield
    = partial "footer"

起初我认为错误只是因为HAML本身被破坏了,但即使是一个非常简单的HAML文件,它只定义了doctype,html,head,title和body标签.然后我怀疑只有ERb文件被用作布局文件 – 我通过将layout.haml重命名为layout.erb来确认,这不会导致错误,而只是显示原始HAML代码.即使保留layout.erb并制作子布局article_layout.haml,在导航到博客文章时也会导致类似的错误,同时使article_layout.erb正常工作.

所以,我怀疑Middleman除了ERb之外不会接受任何布局文件.但是,我在文档中找不到一个关于此的东西,我甚至看到过所有的例子都有layout.haml文件,它们完美无缺.我的与众不同吗？是否需要使用midman init设置一个标志才能使用HAML文件进行布局？这是怎么回事？