rails 4, link_to not working with destroy action when jquery, jquery_ujs is required

Question

How come the destroy action is incompatible once jquery is required in the application.js file? How do you get the destroy action to work again without disregarding jquery?

posts index view:

h1 Blog
- @posts.each do |post|
 h2 = link_to post.title, post
 p = post.content
 p = link_to 'Edit', edit_post_path(post)
 p = link_to 'Delete', post, data: {confirm: "Are you sure?"}, method: :delete
 br

p = link_to 'Add a new post', new_post_path

destroy action in posts controller:

def destroy
 @post = Post.find params[:id]
 @post.destroy

 redirect_to posts_path, :notice => "Your post has been deleted"
end

application.js:

= require jquery
= require jquery_ujs
//= require turbolinks
//= require_tree

As soon as I comment those two out the destroy action works again. Without the comment, the delete link just fires the show action...your thoughts?

Answer 1

So the asset pipeline does something special with those comments. The presence of a comment of the form

//= require jquery

instructs the preprocessor to include that file when building the application.js as served up to clients of the application. When you remove the comment, you're removing this behavior - and the resulting libraries are not compiled into the final application.js served up by the app.

The upshot of this is that you're misinterpreting how the required directive works. It ONLY works inside a comment. When you remove the comment tag you stop including the library.

Answer 2

application.js is a manifest file so the syntax is suppose to have those comments. See http://guides.rubyonrails.org/asset_pipeline.html#manifest-files-and-directives

Answer 3

If you copied and pasted the code from the website http://guides.rubyonrails.org/getting_started.html , try to type it in instead.

Or delete all the leading 'whitespaces' which may not be whitespaces. Somehow I got ascii 160 instead ascii 32 (the whitespace character).

I'm sure how it happen but copy and paste it again is working fine now.