views

A guide to building Rails views, the HTML pages a Rails app shows, and the helper methods that format their content.

In plain words
What is it for?
Use it when organizing partials, writing presentation helpers, building forms, and applying semantic HTML and output escaping.
Why use it?
It helps keep display code separate from business rules, so templates stay easier to read, test, and maintain.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/levifig/rails-instructions/views
Clone the repo
git clone --depth 1 https://github.com/levifig/rails-instructions

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,041 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.01041
Opus 5 $0.00000 $0.00521
Sonnet 5 $0.00000 $0.00208
Haiku 4.5 $0.00000 $0.00104

Measured yesterday against content hash cca8e6b93467, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

views scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/rails/views.mdc · 192 lines

How it starts

The opening of the file, as written. The whole thing — 192 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Rails Views and Helpers Guide

Core Philosophy

  • Keep views simple and logic-free
  • Use helpers for presentation logic only
  • Leverage Rails' built-in view helpers
  • Follow semantic HTML principles
  • Optimize for readability and maintainability

View Architecture Principles

  • Separate presentation from business logic completely
  • Use partials for reusable view components
  • Keep views focused on displaying data
  • Implement proper HTML semantics
  • Design for progressive enhancement

Helper Organization

  • Keep helpers focused on specific presentation tasks
  • Group related helpers in dedicated modules
  • Use ApplicationHelper for truly global helpers
  • Document complex helper methods
  • Test helpers with various input scenarios

Rails Helper Usage

  • Prefer Rails helpers over raw HTML
  • Use semantic Rails form helpers
  • Leverage Rails' built-in formatting helpers
  • Implement proper escaping for security
  • Follow Rails conventions for helper naming

Partial Best Practices

  • Name partials with leading underscore
  • Keep partials small and focused
  • Pass locals explicitly for clarity
  • Avoid instance variables in partials
  • Document partial requirements

Form Design Principles

  • Use form_with for all forms
  • Implement proper form accessibility
  • Add appropriate ARIA labels
  • Use Rails form builders consistently
  • Handle errors at the field level

Asset Management

  • Use Rails asset helpers for all assets
  • Implement proper image alt texts
  • Leverage asset fingerprinting
  • Configure CDN for production assets
  • Optimize images before serving

Internationalization

  • Extract all text to locale files
  • Use Rails I18n helpers consistently
  • Design views for text expansion
  • Handle pluralization properly
  • Test with multiple locales

Performance Optimization

  • Use fragment caching for expensive views
  • Implement Russian doll caching
  • Avoid N+1 queries in views
  • Lazy load below-fold content
  • Profile view rendering times

JavaScript Integration

  • Use data attributes for JavaScript hooks
  • Avoid inline JavaScript in views
  • Implement CSP-compliant practices
  • Use Stimulus for behavior
  • Keep JavaScript unobtrusive

Read the full file on GitHub · 192 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 192 lines · 0 tokens per session scan A cca8e6b93467

Subscribe to this mod's changes

views is a cursor rule published in the GitHub repository levifig/rails-instructions (54 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,041 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.