Problems with Mongrel

rubyonrails-talk
1

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

2

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

3

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

4

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

5

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

6

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