ReddRadar
Agent skill
Wheels Debugging
Troubleshoot common Wheels errors and provide debugging guidance. Use when encountering errors, exceptions, or unexpected behavior. Provides error analysis, common solutions, and debugging strategies for Wheels applications.
Install this agent skill to your Project
npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/development/wheels-debugging
SKILL.md
Wheels Debugging
Common Errors
"No matching function [RENDERPAGE] found"
Cause: Using wrong function name - CFWheels uses renderView() not renderPage()
Solution: Change to correct function name
❌ renderPage(action="new")
✅ renderView(action="new")
"Missing argument name" Error
Cause: Mixed positional and named arguments
Solution: Use consistent argument style
❌ hasMany("comments", dependent="delete")
✅ hasMany(name="comments", dependent="delete")
❌ .resources("sessions", only="new,create")
✅ .resources(name="sessions", only="new,create")
"key [onCreate,onUpdate] doesn't exist"
Cause: Using comma-separated values in validation when parameter
Solution: Remove the when parameter - validations run on both create and update by default
❌ validatesConfirmationOf(properties="password", when="onCreate,onUpdate")
✅ validatesConfirmationOf(properties="password")
"Can't cast Object type [Query] to [Array]"
Cause: Using Array functions on queries
Solution: Use query methods
❌ ArrayLen(post.comments())
✅ post.comments().recordCount
"Association not found" Error
Cause: Association not properly defined or typo
Solution:
- Check model config() for association definition
- Verify association name matches
- Check model name spelling
"Table not found" Error
Cause: Migration not run or table name mismatch
Solution:
wheels dbmigrate latest
"Column not found" Error
Cause: Property doesn't exist in database
Solution:
- Add column via migration
- Check property name spelling
- Verify case sensitivity
Debugging Tools
Enable Debug Output
// In config/settings.cfm
set(showDebugInformation=true);
set(showErrorInformation=true);
Inspect Variables
<cfdump var="#post#" label="Post Object">
<cfabort>
Check SQL Queries
// Wheels logs all SQL to debugging output
// Look for red SQL queries (errors)
Browser Testing for Debugging
When debugging UI/view issues, use browser MCP tools to verify:
Check Page Rendering
// Use available MCP tool (in order of preference):
// Option 1: Puppeteer MCP (preferred)
mcp__puppeteer__puppeteer_navigate(url="http://localhost:PORT/controller/action")
mcp__puppeteer__puppeteer_screenshot(name="debug-screenshot")
// Option 2: Playwright MCP
mcp__playwright__playwright_navigate(url="http://localhost:PORT/controller/action")
mcp__playwright__playwright_screenshot()
// Option 3: Browser MCP (fallback)
mcp__browsermcp__browser_navigate(url="http://localhost:PORT/controller/action")
mcp__browsermcp__browser_screenshot()
Verify Form Submissions
// Navigate to form
mcp__puppeteer__puppeteer_navigate(url="http://localhost:PORT/posts/new")
// Fill and submit
mcp__puppeteer__puppeteer_click(selector="input[name='post[title]']")
// Check for errors in response
Check for JavaScript Errors
Use browser console output to identify client-side issues that might affect form submissions or dynamic content.
Generated by: Wheels Debugging Skill v1.1
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