Copilot instructions

1---
2description: Rails Views and Helpers Guide
3applyTo: "app/views/**/*.html.erb,app/helpers/**/*.rb"
4---
5 
6# Rails Views and Helpers Guide
7 
8## Core Philosophy
9 
10- Keep views simple and logic-free
11- Use helpers for presentation logic only
12- Leverage Rails' built-in view helpers
13- Follow semantic HTML principles
14- Optimize for readability and maintainability
15 
16## View Architecture Principles
17 
18- Separate presentation from business logic completely
19- Use partials for reusable view components
20- Keep views focused on displaying data
21- Implement proper HTML semantics
22- Design for progressive enhancement
23 
24## Helper Organization
25 
26- Keep helpers focused on specific presentation tasks
27- Group related helpers in dedicated modules
28- Use ApplicationHelper for truly global helpers
29- Document complex helper methods
30- Test helpers with various input scenarios
31 
32## Rails Helper Usage
33 
34- Prefer Rails helpers over raw HTML
35- Use semantic Rails form helpers
36- Leverage Rails' built-in formatting helpers
37- Implement proper escaping for security
38- Follow Rails conventions for helper naming
39 
40## Partial Best Practices
41 
42- Name partials with leading underscore
43- Keep partials small and focused
44- Pass locals explicitly for clarity
45- Avoid instance variables in partials
46- Document partial requirements
47 
48## Form Design Principles
49 
50- Use `form_with` for all forms
51- Implement proper form accessibility
52- Add appropriate ARIA labels
53- Use Rails form builders consistently
54- Handle errors at the field level
55 
56## Asset Management
57 
58- Use Rails asset helpers for all assets
59- Implement proper image alt texts
60- Leverage asset fingerprinting
61- Configure CDN for production assets
62- Optimize images before serving
63 
64## Internationalization
65 
66- Extract all text to locale files
67- Use Rails I18n helpers consistently
68- Design views for text expansion
69- Handle pluralization properly
70- Test with multiple locales
71 
72## Performance Optimization
73 
74- Use fragment caching for expensive views
75- Implement Russian doll caching
76- Avoid N+1 queries in views
77- Lazy load below-fold content
78- Profile view rendering times
79 
80## JavaScript Integration
81 
82- Use `data` attributes for JavaScript hooks
83- Avoid inline JavaScript in views
84- Implement CSP-compliant practices
85- Use Stimulus for behavior
86- Keep JavaScript unobtrusive
87 
88## Security Practices
89 
90- Always escape user-generated content
91- Use Rails sanitize helpers appropriately
92- Implement Content Security Policy
93- Avoid raw HTML output
94- Validate all user inputs
95 
96## Responsive Design
97 
98- Design mobile-first
99- Use semantic HTML elements
100- Test on actual devices
101- Implement proper touch targets
102- Consider performance on mobile
103 
104## Accessibility Guidelines
105 
106- Use semantic HTML elements
107- Provide proper ARIA labels
108- Ensure keyboard navigation works
109- Test with screen readers
110- Meet WCAG 2.1 AA standards
111 
112## Testing View Code
113 
114- Test complex helpers thoroughly
115- Use system tests for user flows
116- Verify accessibility in tests
117- Test error states explicitly
118- Check responsive behavior
119 
120## View Component Patterns
121 
122- Consider ViewComponent for complex UI
123- Keep components focused and reusable
124- Test components in isolation
125- Document component interfaces
126- Use slots for flexible content
127 
128## Email Views
129 
130- Design for email client limitations
131- Use inline styles for emails
132- Test across email clients
133- Provide text alternatives
134- Keep email templates simple
135 
136## Error Pages
137 
138- Design custom error pages
139- Keep error pages self-contained
140- Provide helpful error messages
141- Include support contact info
142- Test error pages thoroughly
143 
144## Layout Best Practices
145 
146- Keep layouts DRY
147- Use yield for content areas
148- Implement proper meta tags
149- Configure CSP headers
150- Design consistent navigation
151 
152## Flash Messages
153 
154- Display flash messages prominently
155- Auto-dismiss success messages
156- Keep error messages visible
157- Use semantic colors
158- Test flash message display
159 
160## Pagination Patterns
161 
162- Implement accessible pagination
163- Use Rails pagination helpers
164- Consider infinite scroll carefully
165- Show current page clearly
166- Handle edge cases properly
167 
168## Search Interface Design
169 
170- Implement live search thoughtfully
171- Provide search feedback
172- Handle no results gracefully
173- Consider search accessibility
174- Optimize search performance
175 
176## Data Presentation
177 
178- Format data consistently
179- Use Rails number helpers
180- Display dates in user timezone
181- Handle empty states gracefully
182- Provide data export options
183 
184## Mobile Optimization
185 
186- Optimize for touch interfaces
187- Consider bandwidth limitations
188- Implement offline capabilities
189- Test on slow connections
190- Use responsive images
191 
192## Development Workflow
193 
194- Use Rails view generators wisely
195- Keep views under version control
196- Document view dependencies
197- Review views for performance
198- Maintain view style guide
199 
200## Common Anti-Patterns
201 
202- Avoid business logic in views
203- Don't query database from views
204- Prevent complex conditionals
205- Skip inline styles
206- Refuse to duplicate view code
207 
208## Best Practices Summary
209 
210- Keep views simple and semantic
211- Use Rails helpers consistently
212- Test views thoroughly
213- Optimize for performance
214- Design for accessibility
215 
216Remember: Views should only present data. Keep logic in models and controllers, and use helpers for presentation formatting.
217