Stimulus Controllers Reference

This document provides a comprehensive reference for all Stimulus controllers in the Heatwave project.

Quick Reference

Controller	Purpose	Primary Usage
`cart`	Add to cart with analytics	Product pages (legacy, prefer Turbo Stream)
`quantity`	Increment/decrement inputs	Cart, product pages
`product-page`	Dynamic product data loading	Product detail pages
`product-filter`	Client-side filtering/sorting	Product grids
`search`	Unified search with Swiftype	Navbar, modals
`lead-form`	Form validation + floating labels	Lead capture forms
`turnstile`	Cloudflare captcha (lazy)	Contact forms
`tooltip`	Bootstrap tooltips (custom options)	Throughout site
`popover`	Bootstrap popovers	Info popovers
`toast`	Auto-dismiss Bootstrap toasts	Flash messages
`clipboard`	Copy to clipboard	Brand assets, CRM
`lazy-frame`	Lazy load on collapse show	Uppy uploaders

Note: Bootstrap dropdowns and collapses use the native data-api (data-bs-toggle), not Stimulus controllers. See Bootstrap Data-API vs Custom Controllers.

WWW Controllers

cart

Handles add-to-cart functionality with toast feedback and analytics tracking.

<button data-controller="cart"
        data-action="click->cart#add"
        data-cart-sku-value="TRT-120-3X5"
        data-cart-name-value="TempZone Floor Heating Kit"
        data-cart-price-value="299.00">
  Add to Cart
</button>

Used in:

app/views/www/products/_add_to_cart.html.erb
app/views/www/products/_out_of_stock.html.erb
app/views/my_carts/_cart.html.erb

quantity

Handles quantity increment/decrement with min/max limits.

<div data-controller="quantity" data-quantity-max-value="10">
  <button data-action="click->quantity#decrement" data-quantity-target="decrement">-</button>
  <input type="number" data-quantity-target="input" value="1">
  <button data-action="click->quantity#increment" data-quantity-target="increment">+</button>
</div>

Used in:

app/views/www/products/_add_to_cart.html.erb
app/views/my_carts/_line_item.html.erb

product-page

Loads dynamic product data (price, stock, CTA) from consolidated JSON endpoint.

<main data-controller="product-page"
      data-product-page-sku-value="TRT-120-3X5"
      data-product-page-data-url-value="/en-US/products/code/TRT-120-3X5/product_data">
  <div id="price-info"><!-- Price loaded here --></div>
  <div id="stock-status"><!-- Stock loaded here --></div>
  <div id="main-call-to-action"><!-- CTA loaded here --></div>
</main>

Used in:

app/views/www/products/_sku_body.html.erb
app/views/www/products/_service_body.html.erb

Client-side filtering and sorting of product grids.

<div data-controller="product-filter">
  <!-- Filter checkboxes -->
  <div data-product-filter-target="filter" data-group="type">
    <input type="checkbox" value=".cable" id="type-cable">
    <label for="type-cable">Cable</label>
  </div>

  <!-- Product cards -->
  <div data-product-filter-target="item" data-type="cable" data-price="299">
    <!-- Card content -->
  </div>
</div>

Used in:

app/views/www/showcases/index.html.erb
app/views/pages/towel-warmer.html.erb

search

Unified search combining Swiftype and Publications.

<form data-controller="search" data-action="submit->search#submit">
  <input type="search" data-search-target="input" placeholder="Search...">
</form>

<div id="searchModal" class="modal">
  <div data-search-target="filters">
    <button data-action="click->search#filter">All</button>
    <button data-action="click->search#filter">Products</button>
  </div>
  <div data-search-target="results"></div>
</div>

Used in:

app/views/www/navbar/_search_form.html.erb
app/views/www/shared/_search_modal.html.erb

lead-form

Form validation and floating labels for lead capture.

<form data-controller="lead-form" data-action="submit->lead-form#onSubmit">
  <div class="form-floating">
    <input type="text" name="lead[name]"
           data-lead-form-target="name floatingField"
           data-action="blur->lead-form#validateOnBlur">
    <label>Name</label>
  </div>
  <button type="submit">Send</button>
</form>

Used in:

app/views/www/leads/_lead_form.html.erb
app/views/www/contact/_side_panel.html.erb

Social sharing with native Web Share API and popup windows.

<div data-controller="social-share"
     data-social-share-url-value="https://www.warmlyyours.com/blog/my-post"
     data-social-share-title-value="My Blog Post">

  <button data-social-share-target="nativeButton"
          data-action="click->social-share#nativeShare" class="d-none">
    Share
  </button>

  <button data-action="click->social-share#copyLink">Copy Link</button>

  <a href="https://linkedin.com/shareArticle?url=..."
     data-action="click->social-share#openPopup">LinkedIn</a>
</div>

Used in:

app/views/components/www/social_share_component.html.erb
app/views/www/posts/show.html.erb

Reviews.io product review widget with lazy loading.

<div data-controller="reviews-io-widget"
     data-reviews-io-widget-config-value='{
       "store": "warmlyyours.com",
       "sku": "TRT-120-3X5"
     }'
     id="reviewsio-product-widget">
</div>

Used in:

app/views/www/products/_reviews_tab.html.erb

landing-page

Google Maps, TOC sidebar, and popovers for landing pages.

<main data-controller="landing-page"
      data-landing-page-markers-value='[{"lat":42.0,"lng":-87.5,"title":"Chicago"}]'>
  <div id="showroom-map"></div>

  <aside id="table-of-contents">
    <button data-landing-page-target="tocExpand"
            data-action="click->landing-page#toggleTOC">
      <i class="fa fa-bars"></i>
    </button>
  </aside>
</main>

Used in:

app/views/www/landing_pages/*.html.erb
app/views/pages/*.html.erb

www-home

Home page popovers for logo carousel.

<main data-controller="www-home">
  <div data-www-home-target="carousel" class="logo-carousel">
    <button class="carousel-logo" data-bs-toggle="popover">
      <img src="/logos/this-old-house.png">
    </button>
  </div>
</main>

Used in:

app/views/www/home/index.html.erb

smart-services

Smart Services appointment booking flow.

<div data-controller="smart-services">
  <input data-smart-services-target="zipInput"
         data-action="keyup->smart-services#checkZip">

  <div data-smart-services-target="appointmentCalendar"
       id="appointment_calendar"></div>

  <button data-action="click->smart-services#scheduleService">Book</button>
</div>

Used in:

app/views/www/smart_services/new.html.erb

Utility Controllers

turnstile

Cloudflare Turnstile captcha with lazy loading.

<div data-controller="turnstile"
     data-turnstile-sitekey-value="0x4AAAAAAA..."
     data-turnstile-theme-value="light"
     data-action="turnstile:success->form#onCaptcha">
</div>

Used in:

app/views/www/leads/_lead_form.html.erb
app/views/www/contact/_form.html.erb

Bootstrap tooltips initialization.

<div data-controller="tooltip">
  <button data-bs-toggle="tooltip" title="Edit item">
    <i class="fa fa-edit"></i>
  </button>
</div>

Used in: Throughout site where tooltips are needed.

clipboard

Copy to clipboard with rich text support.

<button data-controller="clipboard"
        data-clipboard-text-value="https://www.warmlyyours.com"
        data-action="click->clipboard#copy"
        data-clipboard-success-content-value="Copied!">
  Copy Link
</button>

Used in:

app/views/pages/brand-assets.html.erb
Via clipboard_copy helper throughout CRM views

lazy-frame

Lazy load content on Bootstrap collapse show.

<button data-bs-toggle="collapse" data-bs-target="#upload-section">
  Add Photo
</button>

<div class="collapse" id="upload-section"
     data-controller="lazy-frame"
     data-lazy-frame-url-value="/uploads/lazy_uppy">
  <div data-lazy-frame-target="placeholder">Loading...</div>
  <div data-lazy-frame-target="content"></div>
</div>

Used in:

app/views/www/leads/_lead_form.html.erb

Best Practices

Base Controller

Extend ApplicationController for common utilities:

import ApplicationController from "./application_controller"

export default class extends ApplicationController {
  connect() {
    if (this.isPreview) return  // Skip during Turbo preview

    // Use observe() for events that can't go in data-action
    this.observe(window, 'thirdPartyEvent', this.handleEvent)
  }
}

ApplicationController provides:

this.isPreview - Check if in Turbo preview (cached restoration)
this.observe(element, event, handler) - Auto-cleanup event listeners

Turbo Compatibility

All controllers are designed to work with Turbo Drive. Key patterns:

❌ AVOID Connection Guards with dataset.*Connected

Don’t do this - it breaks Turbo cache restoration:
```
// BAD: Prevents controller from working after back navigation
if (this.element.dataset.myControllerConnected === 'true') return
this.element.dataset.myControllerConnected = 'true'
```
Stimulus safely handles controller instances. The connection guard pattern interferes with Turbo’s cache restoration because the flag persists in the cached DOM but the controller instance is new.

Stop Event Propagation for Actions

Prevent double-firing from event bubbling:

increment(event) {
  event.stopPropagation()  // Stop bubbling to parent controllers
  event.preventDefault()   // Prevent default browser behavior
  // ... action logic
}

Debounce Rapid Actions

Prevent rapid clicks from double-firing:

connect() {
  this.lastActionTime = 0
}

canExecuteAction() {
  const now = Date.now()
  if (now - this.lastActionTime < 100) return false  // 100ms debounce
  this.lastActionTime = now
  return true
}

increment(event) {
  event.stopPropagation()
  if (!this.canExecuteAction()) return
  // ... action logic
}

Lock UI During Async Operations

async add(event) {
  event.stopPropagation()
  event.preventDefault()

  const button = event.currentTarget
  if (this.isProcessing || button.disabled) return

  this.isProcessing = true
  button.disabled = true

  try {
    await this.executeAction()
  } finally {
    this.isProcessing = false
    button.disabled = false
  }
}

Skip During Preview: For expensive operations (API calls, animations)

// Using ApplicationController
if (this.isPreview) return

// Or manually
if (document.documentElement.hasAttribute("data-turbo-preview")) return

Cleanup on Disconnect: Always clean up listeners and third-party instances

disconnect() {
  if (this.flatpickrInstance) this.flatpickrInstance.destroy()
}

Event Handling

Always prefer data-action over manual addEventListener:

<!-- Good: Element events -->
<button data-action="click->my-controller#doSomething">Click</button>

<!-- Good: Window/document events -->
<div data-action="resize@window->my-controller#onResize">
<div data-action="keydown@document->my-controller#onKeydown">

<!-- Avoid: Manual listeners require cleanup -->
this.element.addEventListener('click', this.doSomething)

For events that can’t use data-action (third-party libraries, custom events):

Extend ApplicationController and use this.observe():

import ApplicationController from "./application_controller"

export default class extends ApplicationController {
  connect() {
    // Third-party library events
    this.observe(this.flatpickr, 'change', this.onDateChange)

    // Custom events from external scripts
    this.observe(window, 'reviews:loaded', this.onReviewsLoaded)
  }
  // No manual cleanup needed - observe() handles it
}

Event Listener Cleanup with `.bind(this)`

Critical: When using .bind(this) with addEventListener, you MUST store the bound function to properly remove it later.

// ❌ BAD: Creates new function each time, can't remove
connect() {
  this.element.addEventListener('change', this.handleChange.bind(this))
}
disconnect() {
  // This creates a DIFFERENT function, listener is NOT removed!
  this.element.removeEventListener('change', this.handleChange.bind(this))
}

// ✅ GOOD: Store bound handler as instance property
connect() {
  this.boundHandleChange = this.handleChange.bind(this)
  this.element.addEventListener('change', this.boundHandleChange)
}
disconnect() {
  if (this.boundHandleChange) {
    this.element.removeEventListener('change', this.boundHandleChange)
  }
}

Controllers that follow this pattern:

tab_persist_controller.js
tom_select_controller.js
offcanvas_reset_controller.js
lazy_modal_controller.js

Using stimulus-use

stimulus-use provides specific high-level behaviors, NOT generic event listeners.

✅ Use stimulus-use for:

useClickOutside - Detect clicks outside element
useIntersection - Visibility/scroll detection (lazy loading)
useDebounce - High-frequency event throttling
useHotkeys - Keyboard shortcuts
useVisibility - Tab visibility changes

❌ stimulus-use does NOT have:

useEventListener - Use data-action or this.observe() instead
usePreview - Use this.isPreview from ApplicationController

import { Controller } from "@hotwired/stimulus"
import { useClickOutside, useDebounce } from "stimulus-use"

export default class extends Controller {
  static debounces = ['search']  // Debounce search method

  connect() {
    useClickOutside(this)  // Calls clickOutside() when clicking outside
    useDebounce(this)      // Debounces methods listed in static debounces
  }

  clickOutside(event) {
    this.close()
  }

  search() {
    // This is debounced automatically
  }
}

Bootstrap Data-API vs Custom Stimulus Controllers

Key Learning: Bootstrap 5’s data-api uses event delegation on document and automatically initializes components via data-bs-toggle attributes. For standard Bootstrap components (dropdowns, collapses), prefer the native data-api over custom Stimulus controllers.

Why?

Bootstrap’s getOrCreateInstance() expects instances to persist across interactions
Custom Stimulus controllers can interfere with this by disposing instances prematurely
The data-api already handles all standard use cases

Recommended approach:

Use native Bootstrap data-api for dropdowns and collapses:

<!-- Just use data-bs-toggle, no Stimulus controller needed -->
<button data-bs-toggle="dropdown">Menu</button>
<div class="dropdown-menu">...</div>

Global Turbo cleanup in client/js/www/setup/turbo.js:

document.addEventListener('turbo:before-cache', () => {
  // Reset dropdown DOM state (DON'T dispose - data-api handles it)
  document.querySelectorAll('[data-bs-toggle="dropdown"]').forEach(el => {
    el.classList.remove('show')
    el.setAttribute('aria-expanded', 'false')
  })
  document.querySelectorAll('.dropdown-menu.show').forEach(menu => {
    menu.classList.remove('show')
    menu.removeAttribute('style')
    menu.removeAttribute('data-popper-placement')
  })

  // Dispose tooltips/popovers (these ARE created programmatically)
  document.querySelectorAll('[data-bs-toggle="tooltip"]').forEach(el => {
    const instance = window.bootstrap?.Tooltip.getInstance(el)
    if (instance) { instance.hide(); instance.dispose() }
  })
})

Use Stimulus controllers only for:
- Custom initialization options (e.g., tooltips with html: true)
- Complex interactions not covered by data-api
- Programmatic control (show/hide from JavaScript)

Using useTurboCache (Tooltips, Popovers, Custom Components)

For components that require programmatic initialization (like tooltips with custom options), use the useTurboCache composable:

import { Controller } from "@hotwired/stimulus"
import { useTurboCache } from "../utils/use_turbo_cache"

export default class extends Controller {
  connect() {
    this.initializeTooltips()
    useTurboCache(this, { cleanup: this.cleanupTooltips.bind(this) })
  }

  initializeTooltips() {
    if (!window.bootstrap?.Tooltip) return
    this.element.querySelectorAll('[data-bs-toggle="tooltip"]').forEach(el => {
      new window.bootstrap.Tooltip(el, { html: true, sanitize: false })
    })
  }

  cleanupTooltips() {
    if (!window.bootstrap?.Tooltip) return
    this.element.querySelectorAll('[data-bs-toggle="tooltip"]').forEach(el => {
      const instance = window.bootstrap.Tooltip.getInstance(el)
      if (instance) { instance.hide(); instance.dispose() }
    })
  }
}

Controllers using this pattern:

tooltip_controller.js - Custom tooltip options
popover_controller.js - Bootstrap popovers
www_home_controller.js - Home page popovers
landing_page_controller.js - Landing page popovers

Locale Handling

NEVER default locale to a static value. Use the locale utility:

import { getLocaleOrDisconnect, getCurrencyForLocale, buildLocalePath } from "../utils/locale"

connect() {
  // For critical controllers - disconnects if locale unavailable
  this.locale = getLocaleOrDisconnect(this, { controllerName: 'my-controller' })
  if (!this.locale) return

  this.currency = getCurrencyForLocale(this.locale)
  this.apiUrl = buildLocalePath('/api/endpoint.json', this.locale)
}

For non-critical operations:

import { getLocale } from "../utils/locale"

someMethod() {
  const locale = getLocale()
  if (!locale) {
    debug.warn('my-controller', 'Cannot proceed - locale unavailable')
    return
  }
  // proceed with locale
}

Why? Silently defaulting to en-US when en-CA is expected causes:

Wrong currency (USD vs CAD)
Wrong product catalog/pricing
Silent data corruption

The locale utility:

Tries window.locale first (set by Rails)
Falls back to URL path extraction (/en-US/...)
Reports to AppSignal if unavailable
Returns null so you can handle gracefully

Debugging

Use the debug utility instead of console.log:

import { debug } from "../utils/debug"

debug('my-controller', 'Connected', { sku: this.skuValue })
debug.warn('my-controller', 'Something unexpected')

Debug logs only appear in development (window.env === 'development').

Turbo Stream Forms vs Stimulus Controllers

Key Learning: For form submissions that need to update multiple parts of the page (cart count, toast, analytics), prefer Turbo Stream responses over complex Stimulus controllers.

Example: Add to Cart

Instead of a complex cart_controller.js that:

Handles fetch requests
Manages button states
Dispatches analytics events
Shows toasts
Updates cart counts

Use a simple form with Turbo Stream:

<%# Form submits via Turbo Stream %>
<%= form_with url: add_item_my_cart_path,
              method: :post,
              data: { controller: "quantity" } do |f| %>
  <%= hidden_field_tag :sku, product.sku %>
  <button type="submit" data-turbo-submits-with="Adding...">
    Add to Cart
  </button>
<% end %>

<%# app/views/my_carts/add_item.turbo_stream.erb %>
<%= turbo_stream.update "cart-count", @cart.line_items.parents_only.size.to_s %>

<%= turbo_stream.toast do %>
  <div class="toast show" data-controller="toast">
    Added <%= @product_info[:name] %> to cart!
  </div>
<% end %>

<%= turbo_stream.analytics_event "Cart - Product Added", {
  sku: @product_info[:sku],
  price: @product_info[:price]
} %>

Benefits:

Server handles all logic (analytics, cart updates)
data-turbo-submits-with handles button loading state automatically
Custom stream actions (toast, analytics_event) keep templates clean
No complex JavaScript state management

Custom Turbo Stream actions are defined in app/javascript/turbo_stream_actions.js:

import { StreamActions } from "@hotwired/turbo"

StreamActions.toast = function() {
  document.getElementById("toast-container")
    .appendChild(this.templateContent.cloneNode(true))
}

StreamActions.analytics_event = function() {
  window.Analytics.track(
    this.getAttribute("event-name"),
    JSON.parse(this.getAttribute("properties"))
  )
}

Advanced Patterns

Outlets API (Cross-Controller Communication)

Use Outlets instead of getControllerForElementAndIdentifier.

Outlets provide type-safe, reactive communication between controllers:

<div data-controller="search"
     data-search-list-outlet="#results-list">
  <input type="text" data-action="input->search#query">
</div>

<ul id="results-list" data-controller="list">...</ul>

export default class extends Controller {
  static outlets = ["list"]

  query(event) {
    if (!this.hasListOutlet) return  // Safety check
    this.listOutlet.filter(event.target.value)  // Direct method call
  }
}

Value Change Callbacks (Reactive State)

Never manually call render(). Change a value and let the callback handle it.

export default class extends Controller {
  static values = { page: { type: Number, default: 1 } }

  // BAD: Imperative
  nextPage() {
    this.pageValue++
    this.loadData()  // Don't call manually
    this.updateUI()  // Don't call manually
  }

  // GOOD: Reactive
  nextPage() {
    this.pageValue++  // Just update state
  }

  pageValueChanged(newPage, oldPage) {
    if (oldPage === undefined) return  // Skip initial
    this.loadData(newPage)
    this.updateUI(newPage)
  }
}

Dispatch Events (Loose Coupling)

Use this.dispatch() for events other controllers can listen to:

this.dispatch("changed", { detail: { value: newValue } })

// In HTML (parent listens)
<div data-controller="cart"
     data-action="quantity:changed->cart#updateTotal">

Template Tags (Dynamic HTML)

Avoid building HTML strings. Use <template> tags:

<div data-controller="nested-form">
  <div data-nested-form-target="items"></div>

  <template data-nested-form-target="template">
    <div class="row">
      <input type="text" name="items[NEW_RECORD][name]">
    </div>
  </template>

  <button data-action="nested-form#add">Add Item</button>
</div>

add(e) {
  e.preventDefault()
  const content = this.templateTarget.content.cloneNode(true)
  // Replace NEW_RECORD with timestamp for uniqueness
  const html = content.querySelector('.row')
  html.innerHTML = html.innerHTML.replace(/NEW_RECORD/g, Date.now())
  this.itemsTarget.appendChild(content)
}

Idempotent 3rd Party Libraries

Turbo caches pages. Hitting “Back” restores from cache and calls connect() again.

export default class extends Controller {
  connect() {
    // Guard: Don't reinitialize if already exists
    if (this.map) return
    this.map = new GoogleMap(this.element, { ... })
  }

  disconnect() {
    // CRITICAL: Clean up for cache
    if (this.map) {
      this.map.remove()
      this.map = null
    }
    // Clear injected DOM if needed
    this.element.innerHTML = ""
  }
}

Stimulus Controllers Reference

Quick Reference

WWW Controllers

cart

quantity

product-page

product-filter

search

lead-form

social-share

reviews-io-widget

landing-page

www-home

smart-services

Utility Controllers

turnstile

tooltip

clipboard

lazy-frame

Best Practices

Base Controller

Turbo Compatibility

Event Handling

Event Listener Cleanup with .bind(this)

Using stimulus-use

Bootstrap Data-API vs Custom Stimulus Controllers

Using useTurboCache (Tooltips, Popovers, Custom Components)

Locale Handling

Debugging

Turbo Stream Forms vs Stimulus Controllers

Advanced Patterns

Outlets API (Cross-Controller Communication)

Value Change Callbacks (Reactive State)

Dispatch Events (Loose Coupling)

Template Tags (Dynamic HTML)

Idempotent 3rd Party Libraries

See Also

Event Listener Cleanup with `.bind(this)`