How to use Slim (or haml) directly with Rack? - ruby

In Sinatra, it's pretty easy to render a slim template upon request:
get '/some_request' do
slim :file_name
end
Since Rack expects a class with a .call method which then returns [status, headers, [body]] array, like:
class RequestManager
def call(env)
return [200, {}, ['why am I in an array?']]
end
end
How do I return the rendered slim template to make Rack happy?
e.g. [200, {}, '<html><head></head><!-- you get the idea --></html>']

You can accomplish this by including the haml gem in your config.ru,
then using
require 'haml' # or put haml in your gemfile and start rack with `bundle exec`
# ...
run lambda {|env|
template = File.read(path)
page = Haml::Engine.new(template).render()
}
# ...
to set your page attribute from your template.

Related

Configuring rack-test to start the server indirectly

Here is my rack application:
class MainAppLogic
def initialize
Rack::Server.start(:app =>Server, :server => "WEBrick", :Port => "8080")
end
end
class Server
def self.call(env)
return [200, {},["Hello, World"]]
end
end
When actually run, it behaves as it should and returns "Hello World" to all requests. I'm having trouble convincing rack-test to work with it. Here are my tests:
require "rspec"
require "rack/test"
require "app"
# Rspec config source: https://github.com/shiroyasha/sinatra_rspec
RSpec.configure do |config|
config.include Rack::Test::Methods
end
describe MainAppLogic do
# App method source: https://github.com/shiroyasha/sinatra_rspec
def app
MainAppLogic.new
end
it "starts a server when initialized" do
get "/", {}, "SERVER_PORT" => "8080"
last_response.body.should be != nil
end
end
When I test this, it fails complaining that MainAppLogic is not a rack server, specifically, that it doesn't respond to MainAppLogic.call. How can I let it know to ignore that MainAppLogic isn't a rack server and just place a request to localhost:8080, because there server has started?
First thing: why the custom class to run the app? You can use the rackup tool, which is the de-facto standard for running Rack apps. Some more details on it here.
Your app code then becomes:
class App
def call(env)
return [200, {}, ['Hello, World!']]
end
end
and with the config.ru
require_relative 'app'
run App.new
you can start the app by running rackup in your project's directory.
As for the error, the message is pretty clear. rack-test expects, that the return value of app method would be an instance of a rack app (an object that responds to call method). Take a look what happens in rack-test internals (it's pretty easy to follow, as a tip—focus on these in given order: lib/rack/test/methods.rb#L30 lib/rack/mock_session.rb#L7 lib/rack/test.rb#L244 lib/rack/mock_session.rb#L30. Notice how the Rack::MockSession is instantiated, how it is used when processing requests (e.g. when you call get method in your tests) and finally how the call method on your app is executed.
I hope that now it's clear why the test should look more like this (yes, you don't need to have a server running when executing your tests):
describe App do
def app
App.new
end
it "does a triple backflip" do
get "/"
expect(last_response.body).to eq("Hello, World")
end
end
P.S.
Sorry for the form of links to rack-test, can't add more than 2 with my current points :P
Your app should be the class name, for example instead of:
def app
MainAppLogic.new
end
You have to use
def app
MainAppLogic
end
You shouldn't need to indicate the port for doing the get, because the rack app runs in the context of the tests; so this should be right way:
it "starts a server when initialized" do
get "/"
last_response.body.should be != nil
end
Also, as a recommendation prefer to use the new expect format instead of the should, see http://rspec.info/blog/2012/06/rspecs-new-expectation-syntax/
And your MainAppLogic, should be something like:
class MainAppLogic < Sinatra::Base
get '/' do
'Hello world'
end
end

Set Up for RSpec in a Sinatra modular app

This is my first attempt with Sinatra. I built a simple classic app, set up RSpec for it, and got it working. Then, I tried to go modular, in a MVC fashion. Even though the app works in the browser, RSpec throws a NoMethodError. I've read Sinatra docs regarding RSpec, also searched a lot here in SO, but I can't find where the bug is. Any clue?
Thank you very much in advance.
Here are my relevant files:
config.ru
require 'sinatra/base'
Dir.glob('./{app/controllers}/*.rb') { |file| require file }
map('/') { run ApplicationController }
app.rb
require 'sinatra/base'
class ZerifApp < Sinatra::Base
# Only start the server if this file has been
# executed directly
run! if __FILE__ == $0
end
app/controllers/application_controller.rb
class ApplicationController < Sinatra::Base
set :views, File.expand_path('../../views', __FILE__)
set :public_dir, File.expand_path('../../../public', __FILE__)
get '/' do
erb :index
end
end
spec/spec_helper.rb
require 'rack/test'
# Also tried this
# Rack::Builder.parse_file(File.expand_path('../../config.ru', __FILE__))
require File.expand_path '../../app.rb', __FILE__
ENV['RACK_ENV'] = 'test'
module RSpecMixin
include Rack::Test::Methods
def app() described_class end
end
RSpec.configure { |c| c.include RSpecMixin }
spec/app_spec.rb
require File.expand_path '../spec_helper.rb', __FILE__
describe "My Sinatra Application" do
it "should allow accessing the home page" do
get '/'
expect(last_response).to be_ok
end
end
The error
My Sinatra Application should allow accessing the home page
Failure/Error: get '/'
NoMethodError:
undefined method `call' for nil:NilClass
# ./spec/app_spec.rb:5:in `block (2 levels) in <top (required)>'
I'm guessing you're following this recipe, correct?
The described_class in this line:
def app() described_class end
is meant to be the class under test, in this case ZerifApp. Try it like so:
def app() ZerifApp end
EDIT
It turns out the above answer is not correct about what described_class does. I assumed it was a placeholder -- actually it is an RSpec method that returns the class of the implicit subject, that is to say, the thing being tested.
The recipe at the link is misleading because of the way it recommends writing the describe block:
describe "My Sinatra Application" do
This is valid RSpec, but it does not define the subject class. Executing described_class in an example for this block will return nil. To make it work, replace the describe block:
describe ZerifApp do
Now described_class will return the expected value (ZerifApp)
https://pragprog.com/book/7web/seven-web-frameworks-in-seven-weeks
It has some source code to get some ideas from.
This has code example too. https://github.com/laser/sinatra-best-practices

Unable to use Warden in Sinatra App: env['warden'] returns nil

I'm writing a Sinatra Rack App and I want to use Warden for authentication. I'm using heroku's toolbelt so I use foreman to run my app. I've found some code that's presumably supposed to get this working. Unfortunately, when I attempt to actually access the Warden env object, it is nil.
I've attempted to use the sinatra_warden gem, but it also has its own bugs (might be related to this one).
config.ru:
require './web.rb'
use Rack::Static, :urls => ["/css", "/img", "/js"], :root => "public"
run MyApp
web.rb:
require 'sinatra'
require 'warden'
require 'data_mapper'
require './config/datamapper.rb'
require './config/warden.rb' # I've tried this inside of MyApp, still didn't work
class MyApp < Sinatra::Base
get '/test' do
env['warden'].authenticate! # env['warden'] is nil :(
end
end
config/warden.rb:
use Rack::Session::Cookie, :secret => ENV['SESSION_SECRET']
use Warden::Manager do |manager|
manager.default_strategies :password
manager.failure_app = MyApp.new
end
Warden::Manager.serialize_into_session { |user| user.id }
Warden::Manager.serialize_from_session { |id| User.get(id) }
Warden::Manager.before_failure do |env,opts|
# Sinatra is very sensitive to the request method
# since authentication could fail on any type of method, we need
# to set it for the failure app so it is routed to the correct block
env['REQUEST_METHOD'] = "POST"
end
Warden::Strategies.add(:password) do
def valid?
params["email"] || params["password"]
end
def authenticate!
u = User.authenticate(params["email"], params["password"])
u.nil? ? fail!("Could not log in") : success!(u)
end
end
Versions:
Sinatra: 1.1.0
Warden: 1.2.1
Rack: 1.4.1
Ruby: 1.9.3p194
Foreman: 0.60.0
Any ideas how to use Warden the set up I've described?
(P.S. Out of curiosity, what exactly is the env variable?)
Rack internally uses the class Rack::Builder to parse your config.ru file and wrap directives to build up the middleware components.
I believe your builder calls to use in config/warden.rb are getting ignored. It may work to remove the directives from that file and add them to the middleware stack in config.ru:
require './web.rb'
use Rack::Session::Cookie, :secret => ENV['SESSION_SECRET']
use Warden::Manager do |manager|
manager.default_strategies :password
manager.failure_app = MyApp.new
end
use Rack::Static, :urls => ["/css", "/img", "/js"], :root => "public"
run MyApp
Put a link to your config/warden in your config.ru
require File.dirname(__FILE__) + '/config/warden'
Read the warden readme. Or look right in the lib/warden.rb
I put
Warden.test_mode!
in place of the env call at the /test path and get a nice blank page at
http://localhost:9292/test
Some bloggers have stated that there isn't a lot of documentation for warden but I disagree. There is a whole wiki. see https://github.com/hassox/warden/wiki
Take it slow and find out how to use middleware in Rack. Here's a very good article https://blog.engineyard.com/2015/understanding-rack-apps-and-middleware
I think maybe you might want to start out with tests as I found a good example and you could use it with your app.
ENV['RACK_ENV'] = 'test'
require 'test/unit'
require 'rack/test'
require File.dirname(__FILE__) + '/web'
class AuthenticationTest < Test::Unit::TestCase
include Rack::Test::Methods
def app
WardenTest #MyApp
end
def test_without_authentication
get '/protected'
assert_equal 401, last_response.status
end
def test_with_bad_credentials
authorize 'bad', 'boy'
get '/protected'
assert_equal 401, last_response.status
end
def test_with_proper_credentials
authorize 'admin', 'admin'
get '/protected'
assert_equal 200, last_response.status
assert_equal "You're welcome, authenticated client", last_response.body
end
end
Then a few routes added to your app.
helpers do
def protected!
return if authorized?
headers['WWW-Authenticate'] = 'Basic realm="Restricted Area"'
halt 401, "Not authorized\n"
end
def authorized?
#auth ||= Rack::Auth::Basic::Request.new(request.env)
#auth.provided? and #auth.basic? and #auth.credentials and
#auth.credentials == ['admin', 'admin']
end
end
get '/' do
"Everybody can see this page"
end
get '/protected' do
protected!
"You're welcome, authenticated client"
end
In my experience working with Ruby, it's always a good idea to start out with tests for any new project. I often test little pieces first though just to gain an understanding of how they work.
Once you get a better understanding of Rack, especially Rack::Builder, you can use
map '/test' do
...all the middleware needed
run App
end
and try out different configurations to see which ones work best for your needs as I'm doing while I write this.
Enjoy! ;-)

How mix in routes in Sinatra for a better structure

I found nothing about how I can mix-in routes from another module, like this:
module otherRoutes
get "/route1" do
end
end
class Server < Sinatra::Base
include otherRoutes
get "/" do
#do something
end
end
Is that possible?
You don't do include with Sinatra. You use extensions together with register.
I.e. build your module in a separate file:
require 'sinatra/base'
module Sinatra
module OtherRoutes
def self.registered(app)
app.get "/route1" do
...
end
end
end
register OtherRoutes # for non modular apps, just include this file and it will register
end
And then register:
class Server < Sinatra::Base
register Sinatra::OtherRoutes
...
end
It's not really clear from the docs that this is the way to go for non-basic Sinatra apps. Hope it helps others.
You could do this:
module OtherRoutes
def self.included( app )
app.get "/route1" do
...
end
end
end
class Server < Sinatra::Base
include OtherRoutes
...
end
Unlike Ramaze, Sinatra's routes are not methods, and so cannot use Ruby's method lookup chaining directly. Note that with this you can't later monkey-patch OtherRoutes and have the changes reflected in Server; this is just a one-time convenience for defining the routes.
I prefer the use of sinatra-contrib gem to extend sinatra for cleaner syntax and shared namespace
# Gemfile
gem 'sinatra', '~> 1.4.7'
gem 'sinatra-contrib', '~> 1.4.6', require: 'sinatra/extension'
# other_routes.rb
module Foo
module OtherRoutes
extend Sinatra::Extension
get '/some-other-route' do
'some other route'
end
end
end
# app.rb
module Foo
class BaseRoutes < Sinatra::Base
get '/' do
'base route'
end
register OtherRoutes
end
end
sinata-contrib is maintained alongside the sinatra project
Well you can also use the map method to map routes to your sinatra apps
map "/" do
run Rack::Directory.new("./public")
end
map '/posts' do
run PostsApp.new
end
map '/comments' do
run CommentsApp.new
end
map '/users' do
run UserssApp.new
end
Just my two cents:
my_app.rb:
require 'sinatra/base'
class MyApp < Sinatra::Base
set :root, File.expand_path('../', __FILE__)
set :app_file, __FILE__
disable :run
files_to_require = [
"#{root}/app/helpers/**/*.{rb}",
"#{root}/app/routes/**/*.{rb}"
]
files_to_require.each {|path| Dir.glob(path, &method(:require))}
helpers App::Helpers
end
app/routes/health.rb:
MyApp.configure do |c|
c.before do
content_type "application/json"
end
c.get "/health" do
{ Ruby: "#{RUBY_VERSION}",
Rack: "#{Rack::VERSION}",
Sinatra: "#{Sinatra::VERSION}"
}.to_json
end
end
app/helpers/application.rb:
module App
module Helpers
def t(*args)
::I18n::t(*args)
end
def h(text)
Rack::Utils.escape_html(text)
end
end
end
config.ru:
require './my_app.rb'

Call Sinatra erb from another class

I need to render a Sinatra erb template inside a class in my controller. I'm having issues calling this though. I've looked in the Sinatra rdocs and have come up with this:
Sinatra::Templates.erb :template_to_render
When I do this, I get the following error:
undefined method `erb' for Sinatra::Templates:Module
Is there a way to call this from another class?
To imitate rendering behavior of Sinatra controller in some other class (not controller) you can create module like this:
module ErbRender
include Sinatra::Templates
include Sinatra::Helpers
include Sinatra::ContentFor
def settings
#settings ||= begin
settings = Sinatra::Application.settings
settings.root = "#{ROOT}/app"
settings
end
end
def template_cache
#template_cache ||= Tilt::Cache.new
end
end
Here you may need to tune settings.root
Usage example:
class ArticleIndexingPostBody
include ErbRender
def get_body
erb :'amp/articles/show', layout: :'amp/layout'
end
end
This will properly render templates with layouts including content_for
why you don't require 'erb' and after use only erb
## You'll need to require erb in your app
require 'erb'
get '/' do
erb :index
end
You could have your class return the template name and render it in the main app.
Of course that's not exactly an answer (I don't have enough rep to add a comment with this account) and you're probably doing just that by now anyway...

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