Generalized filters in Camping

camping_hooks.rb

#
# include the CampingHooks module in TheApp
#
module CampingHooks
  module ClassMethods
    
    def set_hook_key(k)
      @hooks ||= {}
      @hooks[k] ||= []
    end
    
    def set_hook_value(k, v)
      set_hook_key(k)
      @hooks[k] << v
    end
    
    def get_hooks
      @hooks ||= {}
    end
    
    def hook(hook_pair, &block)
      hook_sym = hook_pair.keys.first
      hook_actions = hook_pair.values.first
      instance_eval <<-EOT
        def #{hook_sym}(actions, &block)
          actions = [actions] unless actions.respond_to?(:each)
          #binding.pry
          actions.each do |action|
            set_hook_value(:#{hook_sym}, [action, block])
          end
        end
      EOT
      send(hook_sym, hook_actions, &block)
    end
    
  end # ClassMethods
  
  def self.included(mod)
    mod.extend(ClassMethods)
  end
  
  def run_filter(sym)
    o = self.class.to_s.split("::")
    app = Object.const_get(o.first)
    filters = app.get_hooks
    app.set_hook_key(sym)
    filters[sym].each do |filter|
      if (filter[0].is_a?(Symbol) && (filter[0] == o.last.to_sym || filter[0] == :all)) ||
         (filter[0].is_a?(String) && /^#{filter[0]}\/?$/ =~ @env.REQUEST_URI)
         self.instance_eval(&filter[1])
      end
    end
  end
  
  def service(*a) # params to controllers, ids n stuff
    override_self = catch(:halt) do
      run_filter(:before_service)
      override_self = super(*a)
      run_filter(:after_service)
      override_self
    end
    override_self
  end
end