Home

Rails active resource link helper

rails , active resource link , ruby on rails , ror

There are many snippets on stack overflow around this topic but
those are mostly dealing with a specific link to a page or a resource e.g. about page or blogs page if you haven’t tried those snippets, you can try this one out:

app/helpers/application_helper.rb #
module ApplicationHelper

    def current?(key, path)
      "#{key}" if current_page? path 
    end

end

_

views/layout/application.html.erb #
<a
    href="<%= url_for(admin_posts_path) %>"
    class="<%= "#{current? "sample_active_link_class", admin_posts_path}" %> normal_class"
    > Posts </a>

This works using the current_page function provided by rails action view url helper. Read more about it here

Basically this current functions takes two arguments which are
key in our case the sample_active_link_class And path
which we have here as admin_posts_path , and returns the key (classname)

if the current_page is matches the given path/url (i.e. admin_posts_path). Else it returns nothing and we fall back to normal_class_name

The above code is sufficient if we’re working with a simple navbar which have doesn’t need
“dynamicness” if lets say we have a navbar & content page like this

T4P4N  | [ ...search ]         |
_______________________________|
Posts* | Hello world           |
       | [first_post, new_tag] |
_______| by t4p4n              |
Tags   | edit | delete         |
       |                       |
_______|_______________________|

* represents active state^ if we click on edit this * will disappear as we’re no longer on the index page but we’re still working with a post resource so it needs to be in active state.

This is when we need the snippet below: #

_

app/helpers/active_resource_helper.rb #
module ActiveResourceHelper

    def on_posts_index_show_edit?
        in_posts? && (action_name == "index" || action_name == "show" || action_name == "edit")
    end
    


    private

    def in_posts?
        return true ? controller_path.split("/")[1] == "posts" : false
    end    
end

_

views/layout/application.html.erb #
<a
    href="<%= url_for(admin_posts_path) %>"
    class="<%= "#{"sample_active_link_class" if on_posts_index_show_edit?}" %> normal_link_class "
    > Posts </a>

How does this^ work? #

here we’re working with just two variables provided by rails to help us in these kind of scenarios, first one is : action_name which as the name suggests, have the value of current action
on the specific page that we’re rendering.

And second one is controller_path which simply returns anything after the base url that is in our case admin/posts, which then split by / and
we get the second item from array returned by split function, and check if its
the same as we want to be.

This is useful when we are creating a navbar for a admin panel
where we need to list all available resources of our application & have actions associated with them like index, create, edit, show, delete etc.

Thanks for reading! #