Administrate: Sidebar fails rendering link_to with NoMethodError: undefined method `to_model' for #<Administrate::Namespace::Resource:0x0000...>

[jaykilleen]

I've recently upgraded to Rails 5.1.5 and running Administrate

gem 'administrate', '~> 0.9.0', git: 'https://github.com/thoughtbot/administrate.git', branch: 'master'

My Administrate sidebar is not rendering and displays the error:

NoMethodError - undefined method `to_model' for #<Administrate::Namespace::Resource:0x00007fdd3e303338>

It occurs in the link_to function at [namespace, resource]. Should this be [namespace, @resource]??

_sidebar.html.erb

        <%= link_to(
          display_resource_name(resource),
          [namespace, resource],
          class: "sidebar__link sidebar__link--#{nav_link_state(resource)}"
        ) %>

[nickcharlton]

Potentially!

I've not heard of this issue elsewhere yet, do you have a sample application I could try out and replicate with?

[minimul]

Replace with

```.erb
<%= link_to(
display_resource_name(resource),
[namespace, resource_index_route_key(resource)],
class: "navigation__link navigation__link--#{nav_link_state(resource)}"
) %>

```

[nickcharlton]

@minimul, do you think you'd be able to open a PR with this?

I'm still not quite sure how this was happening, so if you'd be able to explain that, that'd be great too!

[minimul]

This is just an edge case customization upgrade issue.

To reproduce one would have had previously ran rails g administrate:views:layout when app/views/admin/application/_sidebar.html.erb was referenced via app/views/layouts/admin/application.html.erb.

Of course app/views/admin/application/_navigation.html.erb has now taken the place of _sidebar.html.erb.

What I've done since and would be the proper approach is to re-run rails g administrate:views:layout and merge ones customizations with the latest Administrate layouts.

Personally, I'd just close this issue.