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ngauthier.com | ||
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arches.io
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| | | | | Pulled this out of a talk by Avdi. This technique is described at 16:00 in the video. It's nice for the user of a library to be able to catch any error coming out of the library, but at the same time, it's nice for a library to pass through basic error types like HTTPError. To solve the problem, you can "tag" the HTTPError with your own error class, essentially raising both types of error: | |
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petr.codes
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| | | | | I really like enums. They can be really powerful if they are used wisely. Let's see what we can do with them in a multilingual Rails app with a little help from PORO (Plain Old Ruby Object). | |
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tenderlovemaking.com
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| | | | | TL;DR: Rack API is poor when you consider streaming response bodies. class FooApplication class ErbPage def to_a head = "the head tag" sleep(2) body = "the body tag" sleep(2) [head, body] end end def call(env) [200, {}, ErbPage.new.to_a] end end class FakeRack def serve(application) status, headers, body = application.call({}) p :status => status p :headers => headers body.each do |string| p string end body.close if body.respond_to?(:close) end end app = FooApplication.new rack = FakeRack.new rack.serve app $ time ruby foo.rb {:status=>200} {:headers=>{}} "the head tag" "the body tag" real 0m4.008s user 0m0.003s sys 0m0.003s class ResponseTimer def initialize(app) @app = app end def call(env) now = Time.now status, headers, body = @app.call(env) headers['X-Response-Took'] = Time.now - now [status, headers, body] end end app = FooApplication.new timer = ResponseTimer.new app rack = FakeRack.new rack.serve timer $ time ruby foo.rb {:status=>200} {:headers=>{"X-Response-Took"=>3.999937}} "the head tag" "the body tag" real 0m4.010s user 0m0.004s sys 0m0.004s class FooApplication class ErbPage def each head = "the head tag" yield head sleep(2) body = "the body tag" yield body sleep(2) end end def call(env) [200, {}, ErbPage.new] end end $ time ruby foo.rb {:status=>200} {:headers=>{"X-Response-Took"=>1.1e-05}} "the head tag" "the body tag" real 0m4.032s user 0m0.027s sys 0m0.016s class ResponseTimer def initialize(app) @app = app end def call(env) now = Time.now status, headers, body = @app.call(env) newbody = [] body.each { |str| newbody << str } headers['X-Response-Took'] = Time.now - now [status, headers, newbody] end end class ResponseTimer class TimerProxy def initialize(body) @now = Time.now @body = body end def close @body.close if @body.respond_to?(:close) $stderr.puts({'X-Response-Took' => (Time.now - @now)}) end def each(&block) @body.each(&block) end end def initialize(app) @app = app end def call(env) status, headers, body = @app.call(env) [status, headers, TimerProxy.new(body)] end end $ time ruby foo.rb {:status=>200} {:headers=>{}} "the head tag" "the body tag" {"X-Response-Took"=>4.000268} real 0m4.044s user 0m0.029s sys 0m0.015s class ResponseTimer def initialize(app) @app = app end def call(env) status, headers, body = @app.call(env) body.extend(Module.new { now = Time.now define_method(:close) do super if defined?(super) $stderr.puts({'X-Response-Took' => (Time.now - now)}) end }) [status, headers, body] end end class EndOfLife attr_reader :callbacks def initialize(app) @app = app @callbacks = [] end def call(env) status, headers, body = @app.call(env) body.extend(Module.new { attr_accessor :eol def close super if defined?(super) eol.callbacks.each { |cb| cb.call } end }) body.eol = self [status, headers, body] end end app = FooApplication.new eol = EndOfLife.new app eol.callbacks << lambda { puts "it finished!" } rack = FakeRack.new rack.serve eol Edit: I just noticed that Rack contains a "timer" middleware similar to the one I've implemented in this blog post. You can view the broken middleware here. | |
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ncona.com
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| | | In my previous post, Getting Started With Arduino UNO R4, I showed how we can upload a sketch into an Arduino board. In this article, we are going to do the same, but this time using the Arduino CLI. Why Arduino CLI? I personally, use neovim for coding, which makes it a necessity for me to be able to compile and upload my code from my terminal. If you prefer the IDE, this article might not be for you, but, understanding the CLI could be useful in the future to automate repetitive tasks or run things in a... | ||
