安装 jQuery Rails 5.1 Yarn 还是 Gem？

Question

if I want to install jQuery on Rails 5.1, what is the differences between install it with:

yarn add jquery

or

gem 'jquery-rails'

Or maybe I have to do both?

Answer 1

The gem jquery-rails and jQuery are different. Read the README on jquery-rails repository and you will see what the gem offers.

If you just want jQuery on your project and you are confortable with yarn, use yarn.

If you want the features that the gem offers, use the gem.

Look at these questions, they can help you.

Why use gems for serving assets instead of the vendor file?

Bootstrap gem in Rails

You don't need to use jquery-rails on Rails 5.1.

From http://guides.rubyonrails.org/5_1_release_notes.html

2.3 jQuery no longer a default dependency

jQuery was required by default in earlier versions of Rails to provide features like data-remote, data-confirm and other parts of Rails' Unobtrusive JavaScript offerings. It is no longer required, as the UJS has been rewritten to use plain, vanilla JavaScript. This code now ships inside of Action View as rails-ujs.

You can still use jQuery if needed, but it is no longer required by default.

So, you will use rails-ujs on new applications. rails-ujs does not need jQuery .

Answer 2

Adding "jquery-rails" to your gemfile allows you to use " jquery_ujs ", which is a sort of "rails compatible" library : it allows you to (eg) add a delete button / link that will delete your target just by specifiying method: delete as a parameter instead of creating a form. ( link_to "delete", "foobar/delete", :method => 'delete' ).

Other than that, there's no much difference.