Class: Rack::ShowStatus

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/show_status.rb

Overview

Rack::ShowStatus catches all empty responses and replaces them with a site explaining the error.

Additional details can be put into rack.showstatus.detail and will be shown as HTML. If such details exist, the error page is always rendered, even if the reply was not empty.

Constant Summary collapse

TEMPLATE =

adapted from Django <www.djangoproject.com> Copyright © Django Software Foundation and individual contributors. Used under the modified BSD license: www.xfree86.org/3.3.6/COPYRIGHT2.html#5

<<'HTML'
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
  <meta http-equiv="content-type" content="text/html; charset=utf-8" />
  <title><%=h message %> at <%=h req.script_name + req.path_info %></title>
  <meta name="robots" content="NONE,NOARCHIVE" />
  <style type="text/css">
    html * { padding:0; margin:0; }
    body * { padding:10px 20px; }
    body * * { padding:0; }
    body { font:small sans-serif; background:#eee; }
    body>div { border-bottom:1px solid #ddd; }
    h1 { font-weight:normal; margin-bottom:.4em; }
    h1 span { font-size:60%; color:#666; font-weight:normal; }
    table { border:none; border-collapse: collapse; width:100%; }
    td, th { vertical-align:top; padding:2px 3px; }
    th { width:12em; text-align:right; color:#666; padding-right:.5em; }
    #info { background:#f6f6f6; }
    #info ol { margin: 0.5em 4em; }
    #info ol li { font-family: monospace; }
    #summary { background: #ffc; }
    #explanation { background:#eee; border-bottom: 0px none; }
  </style>
</head>
<body>
  <div id="summary">
    <h1><%=h message %> <span>(<%= status.to_i %>)</span></h1>
    <table class="meta">
      <tr>
        <th>Request Method:</th>
        <td><%=h req.request_method %></td>
      </tr>
      <tr>
        <th>Request URL:</th>
      <td><%=h req.url %></td>
      </tr>
    </table>
  </div>
  <div id="info">
    <p><%=h detail %></p>
  </div>

  <div id="explanation">
    <p>
    You're seeing this error because you use <code>Rack::ShowStatus</code>.
    </p>
  </div>
</body>
</html>
HTML

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ ShowStatus

Returns a new instance of ShowStatus.



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# File 'lib/rack/show_status.rb', line 19

def initialize(app)
  @app = app
  @template = ERB.new(TEMPLATE)
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/rack/show_status.rb', line 24

def call(env)
  status, headers, body = response = @app.call(env)
  empty = headers[CONTENT_LENGTH].to_i <= 0

  # client or server error, or explicit message
  if (status.to_i >= 400 && empty) || env[RACK_SHOWSTATUS_DETAIL]
    # This double assignment is to prevent an "unused variable" warning.
    # Yes, it is dumb, but I don't like Ruby yelling at me.
    req = req = Rack::Request.new(env)

    message = Rack::Utils::HTTP_STATUS_CODES[status.to_i] || status.to_s

    # This double assignment is to prevent an "unused variable" warning.
    # Yes, it is dumb, but I don't like Ruby yelling at me.
    detail = detail = env[RACK_SHOWSTATUS_DETAIL] || message

    html = @template.result(binding)
    size = html.bytesize

    response[2] = Rack::BodyProxy.new([html]) do
      body.close if body.respond_to?(:close)
    end

    headers[CONTENT_TYPE] = "text/html"
    headers[CONTENT_LENGTH] = size.to_s
  end

  response
end

#h(obj) ⇒ Object

:nodoc:



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# File 'lib/rack/show_status.rb', line 54

def h(obj)                  # :nodoc:
  case obj
  when String
    Utils.escape_html(obj)
  else
    Utils.escape_html(obj.inspect)
  end
end