Compose Patterns Reference

Quick reference for Compose organization patterns. Claude loads this automatically when working with Compose code.

Breaking Up Components

When to Extract

• •Extract: Functions >= 15 lines, independently useful, or complex logic
• •Keep inline: Functions < 15 lines, tightly coupled to parent

Visibility Rules

Parameter Passing

Pass Specific Parameters

// GOOD - Pass only what's needed
@Composable
fun UserCard(
  name: String,
  email: String,
  modifier: Modifier = Modifier,
) {
  UserCardHeader(name = name)  // Only needs name
  UserCardBody(email = email)  // Only needs email
}

// BAD - Passing entire object
@Composable
fun UserCard(
  user: User,  // 20+ properties but only 2 needed
  modifier: Modifier = Modifier,
)

Exception: When object is @Immutable/@Stable and most fields are used.

Parameter Order

1. •Required callbacks (onClick, onDismiss)
2. •Required data parameters
3. •modifier: Modifier = Modifier
4. •Optional parameters with defaults
5. •Content lambda (always last)

File Organization

components/
├── MyComponent.kt           # Main component
├── MyComponentDefaults.kt   # Defaults object (if complex)
└── internal/
    └── MyComponentHeader.kt # Extracted internal composables

Preview Guidelines

• •Add previews for extracted components in separate files
• •Use NamedPreviewParameterProvider for multiple states

Documentation

See .docs/compose/ for complete patterns:

• •composable-organization.md - Breaking up composables
• •naming-structure.md - Naming conventions
• •modifiers.md - Modifier patterns
• •previews.md - Preview configuration