Meta tags with slim-rails

Question

I am currently working on a site sweep and am attempting to refine meta presentation for an app already in production. Specifically, the tags seem to live in the _head.html.slim file.

Example of way meta tag is currently represented in app:

    - if content_for?(:description)
meta name="description" content=content_for(:description)

What I would like to replace it with:

    <meta property="og:description" content="DESCRIPTION OF SITE HERE"/>

Am I on the correct track? I am hesitant to completely wipe the "if content_for?(:description) bit.

I have not worked with slim-rails before, and am thrown off. I've gone through some of the documentation on slim gem, but it defines implementation of meta tags in a completely different manner than what I am currently seeing in the _head.html.slim file.

Any advice would be greatly appreciated.

Answer 1

content_for is actually part of Rails and has very little to do with Slim. yield and content_for let you assign "blocks" of content in your layouts that can be filled dynamically by views.

This is a plain ERB example of dynamically assigning a page title:

# app/views/layouts/application.html.erb
<title>MyApp | <%= content_for?(:title) ? yield(:title) : "Foo" %>

Then in your views you can provide content with content for:

# app/views/products.html.erb
<%- contents_for(:title, "Products" ) -%>

The end result is that the page title will read MyApp | Products when you visit /products.

For your example you could simply provide the content for the description in your views.

# app/views/user/show.slim
- content_for(:description, "#{ @user.name } on MyApp")
# or we use provide to tell the layout to stop looking for more contents.
- provide(:description, "#{ @user.name } on MyApp")

And set it up to display a default in case there is no content provided.

= meta name="description" content= content_for?(:description) ? yield(:description) : "The awesomest app on the interwebs."

To clean this up you might want to employ a helper method.

module ApplicationHelper
  # ...
  def og_description(default)
    # note that we use content_for and not yield since we want
    # the value - not to yield (print) to the buffer.
    disc = content_for?(:description) ? content_for(:description) : default 
    tag(:meta, {
      property: "og:description",
      content: disc
    })
  end
end

This will let you do:

= og_description("The awesomest app on the interwebs.")