lib/rack/toolbar.rb
require "rack/toolbar/version"
# Subclasses must define a render method which returns the snippet of HTML that will be inserted into the response body
# according to the INSERTION_METHOD and INSERTION_POINT. By default this is set before to the closing </body> tag.
module Rack
class Toolbar
CONTENT_TYPE_REGEX = /text\/html|application\/xhtml\+xml/
INSERTION_METHOD = :before # alternatively :after
INSERTION_POINT = "</body>" # alternatively "<body>" to have injection at the top of the body, or whatever else floats your boat.
SNIPPET = <<EOS
<h1>Welcome to rack-toolbar</h1>
<ul>
<li>Define render in Middleware subclass of Rack::Toolbar to return an HTML snippet.</li>
<li>or</li>
<li>Pass an HTML snippet as an argument and use Rack::Toolbar directly: Rack::Toolbar.new(snippet).</li>
<li>or</li>
<li>Redefine Rack::Toolbar::SNIPPET and ignore with the warnings.</li>
</ul>
EOS
def initialize(app, options = {})
@app = app
@options = options || {}
@options[:snippet] ||= self.class::SNIPPET
@options[:insertion_point] ||= self.class::INSERTION_POINT
@options[:insertion_method] ||= self.class::INSERTION_METHOD
end
def call(env)
@env = env
@status, @headers, @response = @app.call(@env)
[@status, @headers, self]
end
# Subclasses may override this method if they have alternate means of deciding which requests to modify.
def okay_to_modify?
return false if is_xhr?
return false unless modifiable_content_type?
true
end
def modifiable_content_type?
@headers["Content-Type"] =~ self.class::CONTENT_TYPE_REGEX
end
def is_xhr?
@headers["HTTP_X_REQUESTED_WITH"] == "XMLHttpRequest"
end
def each(&block)
if okay_to_modify?
body = ""
@response.each {|part| body << part }
index = body.rindex(@options[:insertion_point])
if index
if @options[:insertion_method] != :before
index += @options[:insertion_point].length
end
body.insert(index, render)
@headers["Content-Length"] = body.bytesize.to_s
@response = [body]
end
end
@response.each(&block)
end
def render
@options[:snippet]
end
end
end