How do you use anchors for IDs in routes in Rails 3?

Question

Imagine a blog with posts and comments. An individual comment's URL might be posts/741/comments/1220.

However, I'd like to make the URL posts/741#1220, or even posts/741#comment-1230.

What's the least intrusive way of doing this, so that redirect_to comment_path(my_comment) points to the correct URL?

Holger Just · Accepted Answer · 2011-02-13T01:00:50.420

69

You could simply use

redirect_to post_path(comment.post, :anchor => "comment-#{comment.id}")

to manually build the URL with the anchor. That way, you can still have the absolute URL to your comments as posts/:post_id/comments/:comment_id in your routes. You can also create a helper method in e.g. application_controller.rb

class ApplicationController
  helper :comment_link

  def comment_link(comment)
    post_path(comment.post, :anchor => "comment-#{comment.id}")
  end
end

edited Feb 13 '11 at 01:00

answered Feb 12 '11 at 23:06

Holger Just

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What would the benefit be of having my absolute URL still be posts/:post_id/comments/:comment_id? – ClosureCowboy Feb 13 '11 at 10:46
@ClosureCowboy: You could still properly define the comments as resources, to e.g. delete or edit them. It depends on your actual requirements if this makes sense to have or not. – Holger Just Feb 13 '11 at 11:27
Is the controller really the best place to put this kind of helper? I'm pondering this issue myself and I don't really know where to put all my "anchor link helpers" – Alexander Kuzmin Nov 19 '13 at 09:52
@AlexanderKuzmin You could also put it into a helper module. If you don't use the helper method in a controller action, you are fine then. Else you would have to include the helper module into your controller class by using `helper MyControllerHelper`. – Holger Just Nov 19 '13 at 10:43

score 1 · Answer 2 · answered Mar 15 '17 at 03:45

Prefer to keep your anchor builder in one place.

class Comment
  ...
  def anchor
    "comment-#{id}#{created_at.to_i}"
  end
end

then

post_path(comment.post, :anchor => comment.anchor)

Adding the created_at.to_i obscures your data a bit more and doesn't harm anything.

How do you use anchors for IDs in routes in Rails 3?

2 Answers2

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