Chapter #20: Simple framework

app/controllers/tests_controller.rb

@@ -4,8 +4,17 @@ def index
     @time = Time.now
   end
 
+  def show
+    render plain: params['id']
+  end
+
   def create
 
   end
 
+  def render_plain
+    headers['Content-Type'] = 'text/plain'
+    render plain: "Plain text response"
+  end
+
 end

config.ru

@@ -1,3 +1,5 @@
 require_relative 'config/environment'
+require_relative 'middleware/logger'
 
+use Logger
 run Simpler.application

config/routes.rb

@@ -1,4 +1,6 @@
 Simpler.application.routes do
+  get '/tests/:id', 'tests#show'
+  get '/plain', 'tests#render_plain'
   get '/tests', 'tests#index'
   post '/tests', 'tests#create'
 end

lib/simpler/application.rb

@@ -28,6 +28,8 @@ def routes(&block)
 
     def call(env)
       route = @router.route_for(env)
+      return @router.not_found(env) unless route
+      route.extract_params(env)
       controller = route.controller.new(env)
       action = route.action
 

lib/simpler/controller.rb

@@ -8,7 +8,9 @@ class Controller
     def initialize(env)
       @name = extract_name
       @request = Rack::Request.new(env)
+      @request.params.merge!(env['params'])
       @response = Rack::Response.new
+      @already_rendered = false
     end
 
     def make_response(action)
@@ -17,7 +19,7 @@ def make_response(action)
 
       set_default_headers
       send(action)
-      write_response
+      write_response unless @already_rendered
 
       @response.finish
     end
@@ -36,18 +38,55 @@ def write_response
       body = render_body
 
       @response.write(body)
+      @already_rendered = true
     end
 
     def render_body
       View.new(@request.env).render(binding)
     end
 
+    def render_string(template)
+      @request.env['simpler.template'] = template
+    end
+
+    def render_error(error_message)
+      status 500
+      @response.write(error_message)
+      @response.finish
+    end
+
+    def render_hash(params)
+      if params.key?(:plain)
+        @request.env['simpler.render'] = :plain
+        @response.write(params[:plain].to_s)
+        @response.finish
+      else
+        render_error("Cannot render template with #{params.keys} options")
+      end
+    end
+
+    def status(status)
+      response.status = status
+    end
+
+    def headers
+      @response.headers
+    end
+
     def params
       @request.params
     end
 
     def render(template)
-      @request.env['simpler.template'] = template
+      case template
+      when String
+        render_string(template)
+      when Hash
+        render_hash(template)
+      else
+        render_error("Cannot render #{template.class} template")
+      end
+      @already_rendered = true
     end
 
   end

lib/simpler/router.rb

@@ -1,4 +1,4 @@
-require_relative 'router/route'
+  require_relative 'router/route'
 
 module Simpler
   class Router
@@ -22,6 +22,16 @@ def route_for(env)
       @routes.find { |route| route.match?(method, path) }
     end
 
+    def not_found(env)
+      method = env['REQUEST_METHOD'].downcase.to_sym
+      path = env['PATH_INFO']
+      Rack::Response.new.then do |response|
+        response.status = 404
+        response.write("[#{method} #{path}] route for current application is not found\n")
+        response.finish
+      end
+    end
+
     private
 
     def add_route(method, path, route_point)

lib/simpler/router/route.rb

@@ -13,6 +13,25 @@ def initialize(method, path, controller, action)
 
       def match?(method, path)
         @method == method && path.match(@path)
+        @method == method && path.match(to_regex(@path))
+      end
+
+      def extract_params(env)
+        request_path_items = env['PATH_INFO'].split('/')
+        path_items = @path.split('/').map { |item| item.sub(':', '') }
+
+        params = Hash[path_items.zip(request_path_items)].delete_if { |k, v| k == v }
+        env['params'] = params
+      end
+
+      private
+
+      def to_regex(path)
+        path.split('/')
+            .map { |string| string.start_with?(':') ? '\d+' : string }
+            .join('/')
+            .concat('$')
+            .then { |regex| Regexp.new regex }
       end
 
     end

logs/log.txt

@@ -0,0 +1,21 @@
+
+    Request: GET
+    Handler: NilClass#
+    Parameters: 
+    Response: 404 [] 
+
+    Request: GET
+    Handler: TestsController#render_plain
+    Parameters: {}
+    Response: 200 [text/plain] plain
+
+    Request: GET
+    Handler: TestsController#index
+    Parameters: {}
+    Response: 200 [text/html] 
+
+    Request: GET
+    Handler: TestsController#show
+    Parameters: {"id"=>"125"}
+    Response: 200 [text/html] plain
+

middleware/logger.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+class Logger
+  def initialize(app)
+    @app = app
+  end
+
+  def call(env)
+    @env = env
+    status, headers, body = @app.call(env)
+
+    log_content = collect_logs(status, headers, body)
+    logging(log_content)
+
+    [status, headers, body]
+  end
+
+  def logging(content)
+    filepath = File.expand_path('logs/log.txt')
+    write_mode = File.exist?(filepath) ? 'a' : 'w'
+    File.write(filepath, content, mode: write_mode)
+  end
+
+  def collect_logs(status, headers, _body)
+    controller = @env['simpler.controller'].class.name
+    action = @env['simpler.action']
+    template = @env['simpler.template'] || @env['simpler.render']
+    parameters = @env['params']
+    """
+    Request: #{@env['REQUEST_METHOD']}
+    Handler: #{controller}##{action}
+    Parameters: #{parameters}
+    Response: #{status} [#{headers['Content-Type']}] #{template}
+    """
+  end
+end