Layout attribute

[eelcoj]

Feature request

I want to check how you feel about adding support for a "layout" attribute in ViewComponent. This should work similarly to Rails partials' layout attribute:

<%= render partial: "user", layout: "shared/admin" %>

This would wrap the user partial with app/views/shared/_admin.html.erb.

For ViewComponent this could be:

<%= render(UserComponent.new(user: @user, layout: AdminComponent)) %>

Motivation

This would come in handy most often when rendering a collection. The ViewComponent renders the collection (eg. li, but not the wrapping element (eg. <ul>).

The only mention of this seems to be here: #198

if this sounds interesting, I am happy to spend some time on it.

[reeganviljoen]

@eelcoj, this is possible with current features, like the slot api for example

<%= render(AdminComponent.new()) do |c| %>
  <% c.with_body do %>
     <%= render(UserComponent.new(user: @user) %>
  <% end %> 
<% end %> 

all that said the example above is a lot more dense and could possibly benefit from a layout api, I would like to however ask @joelhawksley what his thoughts are.

[joelhawksley]

@eelcoj thank you for taking the time to share your idea here!

I honestly had never heard of the layout option for rendering partials before you mentioned it. Unfortunately, ViewComponent does not control the initializer of ViewComponent::Base subclasses, so the API you proposed is not possible. I could see a couple of options:

Add with_layout macro:

render(MyComponent.new(arg: "foo").with_layout(MyLayout)

Add layout option to with_collection only:

render(CollectionComponent.with_collection(@items, layout: "foo")

Either way, we'd probably have to support both template file and component layouts. My instinct is to do with_layout. What do you think?

[joelhawksley]

@eelcoj @reeganviljoen thinking about this some more, I realized that we could probably just rely on the built-in Rails API:

render(MyComponent.new, layout: "foo")

To support this, we'll need to make an update to Rails core here: https://github.com/rails/rails/blob/a34fc56f9170dea2b0dfd2a6138c2b57bab35cda/actionview/lib/action_view/helpers/rendering_helper.rb#L149 to pass the layout option to render_in.

I hope to be able to work on a patch for this soon 🤞🏻

[eelcoj]

@joelhawksley That would be even cooler! Let me know if I can help in any way!

[reeganviljoen]

@joelhawksley Agreed this seems like a great idea, and also let me know if you need any help getting a patch done