Variables

Variables in Digia allow you to store and manage data throughout your app. They come in three main categories: Basic Data Types for storing standard values, Controller Types for controlling widget behavior and runtime interactions, and Action Types for storing executable action flows.

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📦 Basic Data Types

Basic data types store standard values like text, numbers, and structured data.

Type	Description	Supported Scopes	Documentation
String	A sequence of characters for text values	All scopes	Learn more
Number	Integers and decimal numbers	All scopes	Learn more
Boolean	true or false values	All scopes	Learn more
JSON	Dynamic map-like structure with key-value pairs	All scopes	Learn more
List	An ordered array of values	All scopes	Learn more

StringNumberBooleanJSONList

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🧰 Controller Types

Controller types are special variables with methods that control widget behavior at runtime. Use the Control Object action to invoke their methods.

Type	Description	Supported Widgets	Supported Scopes	Documentation
Scroll Controller	Controls scrolling behavior	ListView, GridView, Smart Scroll View, Animation Builder	Entity Variables, Entity Params, State Container Variables	Learn more
Page Controller	Manages page navigation in PageView	PageView, Animation Builder	Entity Variables, Entity Params, State Container Variables	Learn more
Text Field Controller	Manages text input fields	Text Form Field	Entity Variables, Entity Params, State Container Variables	Learn more
Stream Controller	Pushes and listens to data streams	Stream Builder	Entity Variables, Entity Params, State Container Variables	Learn more
Async Controller	Manages async state and cache invalidation	Future Builder	Entity Variables, Entity Params, State Container Variables	Learn more
Timer Controller	Controls timer operations	Timer	Entity Variables, Entity Params, State Container Variables	Learn more

Scroll ControllerPage ControllerText Field ControllerStream ControllerAsync ControllerTimer Controller

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⚡ Action Types

Action types store executable action flows that can be invoked dynamically. Use the Execute Callback action to run stored actions.

Type	Description	Use Cases	Supported Scopes	Documentation
Action	Stores an ActionFlow that can be executed later	Component callbacks, dynamic event handlers, reusable action sequences	Entity Params (components only)	Learn more

https://github.com/Digia-Technology-Private-Limited/digiaDocs/blob/main/docs/state-and-data/variables/action-types/action.md

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� Variable Scope

Variables can be defined in different scopes depending on where you need to use them. Each scope supports different variable types:

App State

Variables defined in App State are:

• Mutable (can be changed)

• Global across the entire app

• Persist across page navigation

• Ideal for user data, authentication state, or app-wide settings

• Supported Types: String, Number, Boolean, JSON, List (JSON Array)

App State uses DUIAppState for reactive state management with optional persistence.

Entity Params

Variables defined in Entity Params are:

• Immutable (read-only)

• Passed as arguments when navigating to pages or instantiating components

• Used to pass data between pages or configure component behavior

• Supported Types: All types (String, Number, Boolean, JSON, List, Controllers, Action*)

• Note: Action variables are supported in component params but not in page params.

Entity Variables

Variables defined in Entity Variables (Page State/Component State) are:

• Mutable (can be changed)

• Scoped to the current page or component

• Reset when navigating away or when component unmounts

• Ideal for temporary UI state, form data, or component-specific logic

• Supported Types: All types except Action variables (String, Number, Boolean, JSON, List, Controllers)

State Container Variables

Variables defined in State Container Variables are:

• Mutable (can be changed)

• Scoped to a specific state container widget

• Reset when the container is destroyed

• Ideal for managing state within complex UI sections

• Supported Types: All types except Action variables (String, Number, Boolean, JSON, List, Controllers)

• Note: Parameters of Action variables cannot be of type Action.

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🎯 Best Practices

• Use appropriate types: Choose the simplest type that fits your data (String for text, Boolean for toggles, etc.)

• Name descriptively: Use clear, descriptive names (userName instead of u1)

• Initialize with defaults: Always set initial values to avoid null/undefined errors

• Choose correct scope: Use App State for global data, Entity Variables for local state, Entity Params for configuration

• One controller per widget: Each controllable widget should have its own controller variable

• Clean up controllers: Close streams and clean up controllers when no longer needed

• Action variables for callbacks: Use Action type variables to store reusable action flows for component communication

• Respect type limitations: Action variables are not supported in App State, Entity Variables, or State Container Variables

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Related Documentation

• DUIAppState - Complete guide to global app state management

• Setting State - How to update variable values

• Control Object - Invoking controller methods

• Execute Callback - Running stored action flows

• Expressions and Operators - Using variables in logic

• API Calls - Storing API response data in variables