Jetpack Compose provides two approaches for text input: value-based and state-based text fields. Here’s a breakdown of their key differences.
State Management
Value-Based Text Fields
- Uses
onValueChange
callback - Manual state handling required
- Developer maintains state in composables/ViewModels
- Risk of async state update issues
- Complex state synchronization across recompositions
State-Based Text Fields
- Uses
TextFieldState
object - Automatic state management
- Handles content, cursor position, selection, composition
- Survives recomposition and configuration changes
- Built-in state persistence
Text Transformations
Value-Based
- Single
VisualTransformation
component - Combines input handling + output formatting
- Manual offset mapping required
- Complex for sophisticated transformation logic
State-Based
- Separated into two stages:
InputTransformation
: Filters input before committing to stateOutputTransformation
: Formats text for display only
- No manual offset mapping needed
- Clear separation of concerns
Line Limits Configuration
Value-Based
- Multiple parameters:
singleLine
,maxLines
,minLines
- Can be ambiguous
- Potential for conflicting configurations
State-Based
- Single
TextFieldLineLimits
parameter - Explicit min/max line definition
- Clear, structured interface
- Less error-prone
Secure Input
Value-Based
- No built-in secure handling
- Custom implementation needed for passwords
- Manual character obfuscation required
State-Based
- Built-in
SecureTextField
composable - Automatic character obfuscation
- Disabled clipboard operations
- Ready-to-use secure input handling
Why State-Based is Recommended
The official documentation recommends state-based text fields because they provide:
- Simplified state management - No manual synchronization needed
- Better architecture - Clear separation between input and output transformations
- Reduced complexity - Unified configuration parameters
- Built-in security - Native secure input support
- Better reliability - Automatic handling of edge cases and lifecycle events
Code Examples
Value-Based Text Field
@Composable
fun ValueBasedTextField() {
var text by remember { mutableStateOf("") }
TextField(
value = text,
onValueChange = { text = it },
label = { Text("Enter text") }
)
}
State-Based Text Field
@Composable
fun StateBasedTextField() {
val textFieldState = rememberTextFieldState()
TextField(
state = textFieldState,
label = { Text("Enter text") }
)
}
Secure Text Field
@Composable
fun SecureTextField() {
val textFieldState = rememberTextFieldState()
SecureTextField(
state = textFieldState,
label = { Text("Password") }
)
}
Best Practices
- Use State-Based Fields for new development
- Migrate Existing Fields gradually to state-based approach
- Handle State Properly in ViewModels when needed
- Consider Security requirements when choosing field type
- Test Edge Cases like configuration changes and recomposition
Conclusion
State-based text fields offer a more robust, maintainable approach to text input in Jetpack Compose. While value-based fields are still functional, the state-based approach reduces boilerplate code and potential bugs, making it the preferred choice for new development.
Related Articles
- Jetpack Compose: Architecture - Understanding the layered architecture of Jetpack Compose
- UI Layer with UDF Pattern - Implementing Unidirectional Data Flow in the UI layer
- Understanding compositionLocalOf vs. staticCompositionLocalOf - Choosing the right CompositionLocal for better performance