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Showing posts from 2016

JavaScript on Rails 2016

Whilst I am primarily a JavaScript programmer, my framework of choice is Ruby on Rails. A lot of JS guys like Node or other frameworks which are JS all the way through, but there's a lot to like about Rails, even in 2016 and it's worth learning another language (Ruby) or two (SQL) in order to get the best environment on which to write your JavaScripts. Before I say what I like about Rails though, I will take you through what I don't like just to balance things out. What I don't like about Rails Asset Pipeline still does not let you use ES6 Modules.  Even at this late stage, one still cannot access ES6 Modules in Rails in a "Railsy" manner. You can either bypass the whole Asset Pipeline or else separate out the JS using Webpack or whatever, but in a standard Rails project, the fact that the asset is generated with unique hash in the file name before the extension pretty much nullifies its use for ES6 Modules which need a static location to store the fi

React: Viewless components

I have been using Facebook's React library for a while now ( and I like it for the most part. The most controversial aspect is the fact that the View is mixed into the Logic using what looks like HTML in the "JavaScript" file using JSX. While it is possible to write React components in plain JavaScript, you must include a render() method. However, it is actually possible to do the following... (in ES6 syntax) render() {   return (null); } Now, why would you want to do such a thing? I thought the whole point was to use React to tie together your view and logic layers (and shouldn't you be abstracting out your heavy logic to plain JS classes?). Well, the main reason you might want to do it is because of React's component lifecycle. In my case, I wanted to trigger some JS to run when the component was loaded, and I happen to be using Turbolinks and React-Rails in a Rails project. This JS had

Testing React components with Jasmine in Rails with the react-rails gem

So in my latest project, we are using Ruby on Rails and the react-rails gem to implement our React components. While react-rails is fine for the most part (and for simple components), there is a severe limitation in that you cannot use ES6 modules (i.e. using the import and export classes) because of the way asset-pipeline works. Asset-pipeline precompiles all your JS into one mega JS file and therefore doesn't allow you to call individual JavaScript components in separate files (because they don't pushed to the server). This is a severe problem which I hope gets fixed soon, but in the meantime don't hold your breath. There are workarounds using Browserify and/or Webpack, but they are messy (Google them for more info). In any case, react-rails does allow simple React components in Rails apps and it mounts them all in the window/global namespace, so you can use a good 75% of React within a Rails application. So now, we come to testing... Facebook uses a testing f

Rolify, Devise, Rspec and Capybara Webkit in Rails

So I was using Rolify, Devise, Rspec and Capybara Webkit in Rails and I ran into a problem with the Warden login_as helper when trying to do a feature spec with :js => true (if you didn't understand any of that, you are probably on the wrong blog). Anyways, while the I was able to log in an admin, Rolify was not able to determine the roles. This is in spite of the fact that I added a role in Factory Girl. FactoryGirl.define do factory :admin do email { } password "password" password_confirmation "password" trait :administrator do after(:create) {|admin| admin.add_role(:administrator)} end end end This worked fine with js turned off, so why was it not working now? So the answer had to do with the following line in rails_helper.rb config.use_transactional_fixtures = true So I believe what happened in Capybara webkit is that it runs in a different thread and while Warden's login_as worked fine