Use when writing ERB templates, partials, view helpers, or Turbo Stream responses - covers partial organization, optional locals, CSS class patterns, collection rendering
View on GitHubZempTime/zemptime-marketplace
vanilla-rails
January 20, 2026
Select agents to install to:
npx add-skill https://github.com/ZempTime/zemptime-marketplace/blob/main/vanilla-rails/skills/views/SKILL.md -a claude-code --skill vanilla-rails-viewsInstallation paths:
.claude/skills/vanilla-rails-views/# Views & Templates
ERB conventions for vanilla Rails applications.
## Partial Organization
**Lowest common ancestor** - place partials at the highest shared directory:
```
# Shared by cards/show and cards/index
app/views/cards/_card.html.erb
# Shared across controllers
app/views/application/_flash.html.erb
# Display variants of same model
app/views/cards/display/_compact.html.erb
app/views/cards/display/_full.html.erb
```
**Never** create deeply nested partials only used in one place.
## Optional Locals
Use `local_assigns.fetch` with explicit defaults:
```erb
<%# Good - explicit default, raises if required %>
<% pinned = local_assigns.fetch(:pinned, false) %>
<% card = local_assigns.fetch(:card) %>
<%# Bad - silent nil, ambiguous intent %>
<% pinned = local_assigns[:pinned] || false %>
```
## CSS Class Helper
Build classes with array + compact + join:
```erb
<%# Good %>
<div class="<%= [
'card',
('card--pinned' if card.pinned?),
('card--closed' if card.closed?)
].compact.join(' ') %>">
<%# Bad - string interpolation %>
<div class="card <%= 'card--pinned' if card.pinned? %>">
```
For complex cases, use `token_list` helper:
```erb
<div class="<%= token_list('card', 'card--pinned': card.pinned?) %>">
```
## Collection Rendering
Always cache, always specify `as:`:
```erb
<%= render partial: 'cards/card',
collection: @cards,
as: :card,
cached: true %>
```
## Turbo Streams
Prepend/append with update for empty states:
```erb
<%# Add item and update counter/empty state %>
<%= turbo_stream.before :cards, @card %>
<%= turbo_stream.update :cards_count, @cards.count %>
<%# Remove and handle empty %>
<%= turbo_stream.remove @card %>
<%= turbo_stream.update :cards_empty, partial: 'empty' if @cards.none? %>
```
## Stimulus Integration
Layer controllers on existing elements:
```erb
<%# Good - multiple controllers on body %>
<body data-controller="keyboard shortcuts dropdown">
<%# Bad - wrapper div just for controllIssues Found: