01-NOTES.txt

SINATRA EXTENSIONS & CONFIGURATION OPTIONS:: ( 2009-02-10 22:31 ) 

Tests made with Edge Sinatra version ( commit 4ab3b3bfcb66ace4f14b35b5d4b259be3742513f )


This is the description of this problem, three (3) test scenarios below:

===========================================================
CASE 1:  Classic.rb (Classic Sinatra App)
===========================================================

  This app works in these three modes:
  
  -- with the default configurations from within the Sinatra::Cache module, ie: nothing set in classic.rb file
  
  -- with the :cache_enabled toggled (true/false) in the classic.rb file.
  
  -- with the :cache_dummy configuration collected from default or classic.rb file.
  
  In other words, NO MAJOR PROBLEMS HERE
  
  
  HOWEVER, when you change the lines (see sinatra_cache.rb::16-17) to 'self.cache_enabled', ie from 'options' to 'self'
  then we get the following error when trying to load the page in the browser:
  
    NoMethodError - undefined method `cache_enabled' for #<Sinatra::Application:0x5a7ee0>
    
    sinatra_cache.rb:26:in `cache'
    ../cache_tests/classic.rb:22:in `GET /'
    .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/methodoverride.rb:24:in `call'
    .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/commonlogger.rb:20:in `_call'
    .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/commonlogger.rb:13:in `call'
    .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/handler/mongrel.rb:59:in `process'
    .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/handler/mongrel.rb:32:in `run'
    ../cache_tests/classic.rb:21
  
  Changing the above 'self.cache_enabled' to 'self.class.cache_enabled' makes things work again


===========================================================
CASE 2: myapp.rb (MyApp < Sinatra::Base) sub-classed app
===========================================================
  
  Performing the same (classic.rb) tests on this file results in the following:
  
  -- default configurations are read from the Sinatra::Cache module
  
  -- we get a deprecation warning:
    ./sinatra_cache.rb:17: warning: The 'options' class method is deprecated; use 'self' instead.
    
  -- no configurations are picked up from myapp.rb.
  
  -- when you change the lines (see sinatra_cache.rb::16-17) to 'self.class.cache_enabled' you get
     the following error:
     
      Read error: #<NoMethodError: undefined method 'cache_enabled' for Class:Class>
      ./sinatra_cache.rb:16:in `cache'
      (__DELEGATE__):2:in `cache'
      ../cache_tests/myapp.rb:27:in `GET /'
      ./vendor/sinatra/lib/sinatra/base.rb:644:in `call'
      ./vendor/sinatra/lib/sinatra/base.rb:644:in `route'
      ./vendor/sinatra/lib/sinatra/base.rb:386:in `instance_eval'
      ./vendor/sinatra/lib/sinatra/base.rb:386:in `route!'
      ./vendor/sinatra/lib/sinatra/base.rb:383:in `catch'
      ./vendor/sinatra/lib/sinatra/base.rb:383:in `route!'
      ./vendor/sinatra/lib/sinatra/base.rb:362:in `each'
      ./vendor/sinatra/lib/sinatra/base.rb:362:in `route!'
      ./vendor/sinatra/lib/sinatra/base.rb:448:in `dispatch!'
      ./vendor/sinatra/lib/sinatra/base.rb:327:in `call!'
      ./vendor/sinatra/lib/sinatra/base.rb:415:in `instance_eval'
      ./vendor/sinatra/lib/sinatra/base.rb:415:in `invoke'
      ./vendor/sinatra/lib/sinatra/base.rb:415:in `catch'
      ./vendor/sinatra/lib/sinatra/base.rb:415:in `invoke'
      ./vendor/sinatra/lib/sinatra/base.rb:327:in `call!'
      ./vendor/sinatra/lib/sinatra/base.rb:316:in `call'
      ./vendor/sinatra/lib/sinatra/base.rb:724:in `call'
      ./vendor/sinatra/lib/sinatra/base.rb:786:in `synchronize'
      ./vendor/sinatra/lib/sinatra/base.rb:721:in `call'
      .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/handler/mongrel.rb:59:in `process'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in `process_client'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `each'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `process_client'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `initialize'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `new'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `initialize'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `new'
      /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `run'
      .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/handler/mongrel.rb:32:in `run'
      ./vendor/sinatra/lib/sinatra/base.rb:709:in `run!'
      ../cache_tests/myapp.rb:32
  
  
  -- when you change the lines (see sinatra_cache.rb::16-17) to 'self.cache_enabled' the app works again,
     but no configurations are picked up from the myapp.rb file.
     


===========================================================
CASE 3: myapp_default.rb (MyApp < Sinatra::Default)
===========================================================
  
  Performing the same (classic.rb) tests on this file results in the following:

  -- default configurations are read from the Sinatra::Cache module

  -- we get a deprecation warning:
    ./sinatra_cache.rb:27: warning: The 'options' class method is deprecated; use 'self' instead.
  
  -- no configurations are picked up from myapp_default.rb.
     
  -- when you change the lines (see sinatra_cache.rb::16-17) to self.class.cache_enabled you get
     the following error:
  
      NoMethodError - undefined method `cache_enabled' for Class:Class:
       sinatra_cache.rb:26:in `cache'
       (__DELEGATE__):2:in `cache'
       ../cache_tests/myapp_default.rb:46:in `GET /'
       .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/methodoverride.rb:24:in `call'
       .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/commonlogger.rb:20:in `_call'
       .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/commonlogger.rb:13:in `call'
       .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/handler/mongrel.rb:59:in `process'
       .../lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/handler/mongrel.rb:32:in `run'
       .../cache_tests/myapp_default.rb:51
  
  
  -- when you change the lines (see sinatra_cache.rb::16-17) to 'self.cache_enabled' no configurations are picked up
     from the myapp_default.rb file.
     



===========================================================
CONCLUSIONS:
===========================================================

--  It is currently (2009-02-10) impossible to write an extension that depends on configurations and 
    that works both in 'classic' and sub-classed modes.
    
    I would consider this a major failing, since configurations of module/extension functionality is very important.



===========================================================
    
Apologies for not being able to write a test suite to highlight these problems, but I couldn't make the tests work. Perhaps that's something for the FAQ or the Extensions pages on the website? ie: how to create a Sinatra app for testing purposes only.

02-sinatra_cache.rb

require 'sinatra/base'

module Sinatra 
    
  # Page Caching module
  # 
  module Cache
    
    # toggle for cache functionality
    set :cache_enabled, true
    # dummy test to see override in the app
    set :cache_dummy, "set in [#{self}]"
    
    def cache(content)
      #  NOTE:: this uses 'options' here, but 'self.class' can also be used, albeit only for classic apps
      if self.class.cache_enabled
      # if options.cache_enabled
       "I SHOULD CACHE THIS = [#{content}] :cache_dummy = [#{options.cache_dummy}]"
      else
       "CACHE DISABLED: I'M IGNORING THIS = [#{content}] :cache_dummy = [#{options.cache_dummy}]"
      end
    end
    
  end #/module Cache
  
  register Cache
  
end #/module Sinatra

03-classic.rb

## SIMPLE TEST APP: Code taken from [http://www.sinatrarb.com/extensions.html].
# 
## ONLY DIFFERENCES IN THIS VERSION IS:
# 
# - loads EDGE Sinatra, since the gem (0.9.0.4) does not support extensions
# - adds load and include of sinatra_cache.rb / Sinatra::Cache
# - adds a set :cache_enabled / :cache_dummy configurations
# 
### SEE NOTES.txt for further info.

require 'rubygems'
require 'vendor/sinatra/lib/sinatra.rb'
require 'sinatra_cache.rb'
include Sinatra::Cache

# toggle for cache functionality
set :cache_enabled, false
# dummy test to see override in the app
set :cache_dummy, "set in [#{self}]"

get '/' do
  cache("Hello World")
end

#/EOF

04-myapp.rb

## SIMPLE TEST APP: Code taken from [http://www.sinatrarb.com/extensions.html].
# 
## ONLY DIFFERENCES IN THIS VERSION IS:
# 
# - loads EDGE Sinatra, since the gem (0.9.0.4) does not support extensions
# - adds load of sinatra_cache.rb and register(Sinatra::Cache)
# - adds a set :cache_enabled / :cache_dummy configurations
# - Hello.run!(:port => 4568 ) at the EOF
# - runs on port 4568

### SEE NOTES.txt for further info.

require 'rubygems'
require 'vendor/sinatra/lib/sinatra.rb'
require 'sinatra/base'
require 'sinatra_cache.rb'

class Hello < Sinatra::Base
  register Sinatra::Cache
  
  # toggle for cache functionality
  set :cache_enabled, false
  # dummy test to see override in the app
  set :cache_dummy, "set in [#{self}]"
  
  get '/' do
    cache("Hello World")
  end
  
end

Hello.run!(:port => 4568 )

#/EOF

05-myapp_default.rb

## SIMPLE TEST APP: Code taken from [http://www.sinatrarb.com/extensions.html].
# 
## ONLY DIFFERENCES IN THIS VERSION IS:
# 
# - loads EDGE Sinatra, since the gem (0.9.0.4) does not support extensions
# - inherits from Sinatra::Default instead of Base
# - adds support for :reloading? to limit the number of reloadings happening
# - adds load of sinatra_cache.rb and register(Sinatra::Cache)
# - adds a set :cache_enabled / :cache_dummy configurations
# - added Hello.run!(:port => 4569 ) unless Hello.reloading? at the EOF
# - runs on port 4569
# 
### SEE NOTES.txt for further info.

require 'rubygems'
require 'vendor/sinatra/lib/sinatra.rb'
require 'sinatra/base'
require 'sinatra_cache.rb'

# Sinatra has an issue with .reloading? being private, so monkey patching it here
# otherwise we get this multiple restarts malarkey going on.
#    == Sinatra/0.9.0.4 has taken the stage on 4569 for development with backup from Mongrel
#    == Sinatra/0.9.0.4 has taken the stage on 4569 for development with backup from Mongrel
#    == Someone is already performing on port 4569!
#    127.0.0.1 - - [05/Feb/2009 22:48:36] "GET / HTTP/1.1" 403 8 0.0018
#    == Sinatra/0.9.0.4 has taken the stage on 4569 for development with backup from Mongrel
#    == Someone is already performing on port 4569!
#    127.0.0.1 - - [05/Feb/2009 22:48:36] "GET /favicon.ico HTTP/1.1" 403 8 0.0008
# 

class Sinatra::Base
  class << self
    public :reloading?
  end
end 

class Hello < Sinatra::Default
  register Sinatra::Cache
  
  # # toggle for cache functionality
  set :cache_enabled, false
  # # dummy test to see override in the app
  set :cache_dummy, "set in [#{self}]"
  
  get '/' do
    cache("Hello World")
  end
  
end

Hello.run!(:port => 4569 ) unless Hello.reloading?

#/EOF