afv-library/skills/applying-slds/references/component-selection.md

Component & Blueprint Selection

How to find the right SLDS artifact for a UI pattern.

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Decision Flow

What framework?
├─ LWC → Check Lightning Base Component (LBC) first
│   ├─ LBC exists → Use it. Done.
│   └─ No LBC → Fall through to SLDS Blueprint
├─ React / Vue / Angular / vanilla → Skip LBC, go to SLDS Blueprint
└─ Any framework → No blueprint match? → Build custom with styling hooks

Step 1: Check for LBC (LWC only)

Lightning Base Components are pre-built, accessible, themed LWC components.

Always check first: Lightning Component Library

Common LBCs and their use cases:

Component	Use Case
lightning-button	All button actions
lightning-input	Text, email, number, date inputs
lightning-combobox	Dropdown selection
lightning-datatable	Tabular data with sorting/selection
lightning-card	Content containers
lightning-modal	Dialog overlays
lightning-icon	SLDS icons
lightning-layout	Responsive grid layout

If an LBC exists, use it. Do not build a custom version from blueprint markup.

Step 2: Search SLDS Blueprints

Blueprints are HTML/CSS patterns that work in any framework. Use when no LBC exists or when not building in LWC.

How to search

# Keyword search
node scripts/search-blueprints.cjs --search "dialog"

# Browse by category
node scripts/search-blueprints.cjs --category "Overlay"

# Get full details for a specific blueprint
node scripts/search-blueprints.cjs --name "modals"

Blueprint categories

Category	Examples
Layout	Cards, Tiles, Page Headers
Forms	Input, Select, Combobox, Checkbox, Radio, Textarea
Navigation	Tabs, Vertical Navigation, Breadcrumbs, Path
Data Display	Data Tables, Trees, Activity Timeline
Feedback	Alert, Toast, Scoped Notifications, Spinners
Overlay	Modals, Popovers, Tooltips, Prompt
Media	Avatar, Carousel, Files, Illustration
Actions	Buttons, Button Groups, Button Icons, Menus

How to read a blueprint YAML

Each file in metadata/blueprints/components/{name}.yaml contains:

name: "Modals"
description: "Dialog overlays..."
category: "Overlay"
slds_classes:
  root: "slds-modal"            # The BEM root class to apply
  elements:                     # Child element classes
    - class: "slds-modal__header"
      purpose: "Contains title and close action"
  modifiers:                    # Size/style variants
    - class: "slds-modal_large"
      usage: "For complex forms or detailed content"
  states:                       # State classes
    - class: "slds-fade-in-open"
accessibility:                  # Required ARIA attributes
  roles: ["dialog"]
  attributes: ["aria-modal", "aria-labelledby"]
example_html: "..."             # Reference markup

Use the root class, add elements for structure, modifiers for variants, and follow accessibility requirements.

Step 3: Custom with Styling Hooks

If no LBC or blueprint matches your need, build custom markup with SLDS styling hooks.

See styling-decision-guide.md for how to apply hooks correctly.

Rules for custom components:

• Use custom class prefixes (my-*, c-*) -- never override slds-* classes
• Use var(--slds-g-*, fallback) for all themeable values
• Follow the blueprint naming pattern (BEM-like) for consistency

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Deep Reference

• Full blueprint details: guidance/blueprints-index.md
• All blueprint YAMLs: metadata/blueprints/components/
• LBC documentation: Lightning Component Library