Any idea why Webrick refuses to start?
require 'sinatra/base'
require 'slim'
class Blog < Sinatra::Base
get '/' do
slim :home
end
end
Running ruby blog.rb does nothing. No error is raised.
The built in web server isn’t started when using the modular style of Sinatra apps. See the docs for the differences between modular and classic styles.
To get it to run like a classic style app, add this line to the bottom of your Blog class:
run! if app_file == $0
Related
I have a modular Sinatra app that runs fine under rackup, that is with a config.ru that has three 'use' statements and one run statement. I am trying to get my head around how to port the application to AWS lambda where API_gateway will provide web server services and just call my app.
I am using the recommended lambda.rb script from https://github.com/aws-samples/serverless-sinatra-sample/blob/master/lambda.rb as my entrypoint. What I don't get is how, in the AWS Lambda micro-clime, do I assemble the modules/layers of my application without rackup and config.ru?
I assume that my noob brain is just missing something really basic in spite of the fact that I have read every blog post, bit of Sinatra and Rack documentation I know of, and the great "Sinatra Up and Running" book. What am I missing?
Upon re-reading the book, "Sinatra: Up and Running" again, it seems that there is a fairly elegant solution. If I set up my lambda.handler entrypoint to point to a simple Sinatra router, then it will be the router that composes the individual controllers into a 'system' which will handle all of my end points. the example from the book:
Example 4-32. Using Sinatra as router
require 'sinatra/base'
class Foo < Sinatra::Base
get('/foo') { 'foo' }
end
class Bar < Sinatra::Base
get('/bar') { 'bar' }
end
class Routes < Sinatra::Base
get('/foo') { Foo.call(env) }
get('/bar') { Bar.call(env) }
end
run Routes
Of course, in my case, I won't need the 'run Routes' line. I will just have my lambda.handler call Routes, as in Routes.call. This seems very doable!
I have a Sinatra application that uses the modular style. Everything works fine apart from my error handler blocks which don't get invoked. Here's the relevant code:
app.rb
require_relative './routes/base'
require_relative './routes/routing'
module Example
class App < Sinatra::Application
use Routes::Base
use Routes::Routing
end
end
base.rb
require 'sinatra/base'
module Example
module Routes
class Base < Sinatra::Application
configure do
# etc.
end
# Error pages.
error 404 do # <- Doesn't get invoked.
erb :not_found
end
error 500 do # <- Doesn't get invoked.
erb :internal_server_error
end
end
end
end
routing.rb
module Example
module Routes
class Routing < Base
get '/?' do
erb :home
end
end
end
end
Why don't my error handlers work?
Thanks in advance.
The use method is for adding middleware to an app, you can’t use it to compose an app like this.
In your example you actually have three different Sinatra applications, two of which are being run as middleware. When a Sinatra app is run as middleware then any request that matches one of its routes is handled by that app, otherwise the request is passed to the next component in the Rack stack. Error handlers will only apply if the request has been handled by the same app. The app that you have defined the error handlers in has no routes defined, so all requests will be passed on down the stack — the error handlers will never be used.
One way to organise a large app like this would be to simply use the same class and reopen it in the different files. This other question has an example that might be useful: Using Sinatra for larger projects via multiple files.
I'm building a Sinatra app that uses TweetStream (which listens for Tweets using EventMachine). I would also like the app to serve pages like a normal Sinatra app but it seems like Sinatra can't "listen" for page requests when it's "listening" for Tweets.
Is this something I can fix by using a different server or structuring my app in a different way? I've tried using WebBrick and Thin.
Here is basically what I'm doing:
class App < Sinatra::Base
# listening for tweets
#client = TweetStream::Client.new
#client.track(terms) do |status|
# do some stuff when I detect terms
end
get '/' do
"Here's some page content!"
end
end
You can mount Sinatra apps within eventmachine (providing you you a awebserver that supports EM i.e., Thin). You should then have full access to the EM reactor loop from your Sinatra app, as well as allowing any other EM plugins to run too.
The Sinatra recipes have a good example:
http://recipes.sinatrarb.com/p/embed/event-machine
here is a very stripped down version of the code:
require 'eventmachine'
require 'sinatra/base'
require 'thin'
def run(opts)
EM.run do
server = opts[:server] || 'thin'
host = opts[:host] || '0.0.0.0'
port = opts[:port] || '8181'
web_app = opts[:app]
dispatch = Rack::Builder.app do
map '/' do
run web_app
end
end
unless ['thin', 'hatetepe', 'goliath'].include? server
raise "Need an EM webserver, but #{server} isn't"
end
Rack::Server.start({
app: dispatch,
server: server,
Host: host,
Port: port
})
end
end
class HelloApp < Sinatra::Base
configure do
set :threaded, false
end
get '/hello' do
'Hello World'
end
get '/delayed-hello' do
EM.defer do
sleep 5
end
'I\'m doing work in the background, but I am still free to take requests'
end
end
run app: HelloApp.new
if you really want to use the tweets streaming feature then you need to run the streaming part as a separate process and write it's results say into a database, then read those records from your sinatra app.
that's how it works the twitter stream listener is a separate thing from your sinatra app and you need some sort of a queue to join them, say redis or db, or something like that.
ok so this is very strange (well is to me), everything in my master branch works fine, I then created a new branch called twitter to conduct some twitter feed implementation. I have done this and was working yesterday on my linux machine.. I have pulled the branch today in a windows environment but when i load the app i now get the regular Sinatra 404 Sinatra doesn’t know this ditty.
This is my profile.rb file
require 'bundler/setup'
Bundler.require(:default)
require 'rubygems'
require 'sinatra'
require './config/config.rb' if File.exists?('./config/config.rb')
require 'sinatra/jsonp'
require 'twitter'
require 'sinatra/static_assets'
class Profile < Sinatra::Base
helpers Sinatra::Jsonp
enable :json_pretty
register Sinatra::StaticAssets
##twitter_client = Twitter::Client.new(
:consumer_key => ENV["CONSUMER_KEY"],
:consumer_secret => ENV["CONSUMER_SECRET"],
:oauth_token => ENV["OAUTH_TOKEN"],
:oauth_token_secret => ENV["OAUTH_SECRET"],
)
get '/' do
erb :index
end
get '/feed' do
jsonp ##twitter_client.user_timeline('richl14').map(&:attrs)
end
end
Config.ru
require './profile'
run Profile
Does anyone have any ideas of what i need to be looking at to solve this? Can anyone speak from experience with this?
Thanks
When you use the classic Sinatra style you use require 'sinatra' and then add routes to the top level. These routes get added to the Sinatra::Application. When you directly run this file, e.g. with ruby my_app.rb, Sinatra runs a built in web server, which will serve the Sinatra::Application app.
When you use the modular style, you use require 'sinatra/base', and then add routes to your Sinatra::Base subclass. In this case directly executing the file doesn’t start the built in server.
In your case you are using the modular style, but have used require 'sinatra'. You create your Profile app, but when you run the file directly Sinatra launches the built in server and serves the Sinatra::Application app. Since you haven’t added any routes to this (they’ve all been added to Profile) it runs but all requests return 404.
One way to get your app to launch you is to use rackup. This will launch the Profile app that you have explicitly set in your config.ru. (Explicitly starting your webserver will also work, e.g. using thin start).
Another possibility would be to add a line like this to the end of your Profile class:
run! if app_file == $0
This tells Sinatra to start the build in server running the Profile app if the file is the same as the Ruby file being executed, in a similar way to how the classic style app is launched. If you use this method you should change require 'sinatra' to require 'sinatra/base' otherwise you will get two servers launched, one after the other (in fact you should probably make that change anyway).
See the Sinatra docs for more info about the difference between classic and modular style.
Not sure if many people are familiar with Scaffolding Extensions for Ruby, but I've looked through their docs, forums, and even the source code of the Heroku test site, and not found an answer.
I made a basic Sinatra app and followed right from the RDoc's instructions:
require 'scaffolding_extensions'
require 'sinatra/base'
class Thingy < Sinatra::Base
scaffold_all_models
end
gives
undefined method 'scaffold_all_models' for Thingy:Class (NoMethodError)
and I know Scaffolding Extensions is loadable because I can successfully set some config variables in its classes.
This works for me:
require 'sinatra/base'
require 'scaffolding_extensions'
class Thingy < Sinatra::Base
scaffold_all_models
end