Problems with Mongrel

Hi community,
for my application, I decided to use a configuration based on YAML.
For this purpose I installed a plugin called "app_config" (I think
there are at least two plugins called "app_config", so I hope that
plugin doesn't cause my problem). I wrote a "settings" controller, so
that non-developers can easily change config values. I think I post
the code here (It's only my first approach to see if this approach is
a good idea, there is still a lot to improve):

class SettingsController < ApplicationController
  before_filter :authorise

  def index
    redirect_to :action => "list"
  end

  def list
    @changeable = YAML::load_file "#{RAILS_ROOT}/config/
change_settings.yml"
    @settings = Settings.params.to_a.flatten &
@changeable.to_a.flatten
  end

  def update
    redirect_to_404 unless request.xhr?
    path_to_settings_yml = RAILS_ROOT + "/config/settings.yml"
    y = YAML::load_file path_to_settings_yml
    changeable = YAML::load_file "#{RAILS_ROOT}/config/
change_settings.yml"
    y["common"][params[:key]] = params[:value]
    File.open(path_to_settings_yml, "w") { |f| f.write(y.to_yaml) }
    render :nothing => true
  end
end

The "update" action is called via link_to_remote:
<%= link_to_remote "Update", {:url => { :action => "update", :key =>
setting}, :with => "'value=' + prompt('Wert', '')" , :method =>
"put" }, {:id => "update_#{setting}"} %>

"Settings" is an instance of the "AppConfig" class provided by the
plugin:
class AppConfig
  def initialize(file = nil)
    @sections = {}
    @params = {}
    use_file!(file) if file
  end
  def use_file!(file)
    begin
      hash = YAML::load(ERB.new(IO.read(file)).result)
      @sections.merge!(hash) {|key, old_val, new_val| (old_val ||
new_val).merge new_val }
      @params.merge!(@sections['common'])
    rescue; end
  end
  def use_section!(section)
    @params.merge!(@sections[section.to_s]) if @sections.key?
(section.to_s)
  end
  def method_missing(param)
    param = param.to_s
    if @params.key?(param)
      @params[param]
    else
      raise "Invalid AppConfig Parameter " + param
    end
  end

  def params
    @params
  end
end

This code works - it's not very good, but it works. But after a value
is written, when I reload the page, the value don't change - although
it's successfully changed in the settings.yml. I'm using the server
provided by Rails 2.1 (started via script/server):
=> Booting Mongrel (use 'script/server webrick' to force WEBrick)
=> Rails 2.1.0 application starting on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
** Starting Mongrel listening at 0.0.0.0:3000
** Starting Rails with development environment...
** Rails loaded.
** Loading any Rails specific GemPlugins
** Signals ready. TERM => stop. USR2 => restart. INT => stop (no
restart).
** Rails signals registered. HUP => reload (without restart). It
might not work well.
** Mongrel 1.1.4 available at 0.0.0.0:3000
** Use CTRL-C to stop.

After I restart the server, the changed value appears on the page. It
seems to me that the server is using some kind of caching mechanism,
but it is also possible that my browser causes the problem (I tested
it with Safari and Firefox). I hope anybody can help me to solve this
problem, it's a very annoying one.

Thank you very much in advance
Christoph

This code works - it's not very good, but it works. But after a value
is written, when I reload the page, the value don't change - although
it's successfully changed in the settings.yml. I'm using the server
provided by Rails 2.1 (started via script/server):

It doesn't look like the AppConfig stuff will reload its file between
requests. I bet that you'd see the changes if you restarted the server
after the update.

Fred

Yes, you are right. If I restart the server I see the changes. Do you
have any ideas how to change the code, so AppConfig reloads the file ?

Christoph

There was a file init.rb provided with the plugin:
c = AppConfig.new
c.use_file!("#{RAILS_ROOT}/config/settings.yml")
c.use_section!(RAILS_ENV)
::Settings = c

You see, this code loads the configuration files. As you said, this
seems to be executed only on server startup. Are there any
possibilities to execute this on every request ?

Christoph

You could reload the file after having made changes. Personally I'd
just have your settings controller modify the settings object so that
it doesn't need reloading.

Fred

Thank you very much, you saved my day :slight_smile: I don't know why I didn't
think of such a simple solution.

Christoph