Widgets/Storage

Variable Widget

Variable Widget

A "Storage" type widget. Variable Widget stores and manages named variables within a workflow. It allows setting and retrieving variable values, supporting both reactive (auto-update) and manual modes. It can be used to share data between widgets or maintain state across a recipe.

 

Inputs

  • set (DataType: Configurable) Sets the variable to the provided value. The data type is determined by the widget's configuration.
  • read (DataType: Anything) Triggers the widget to output the current value of the variable.

Outputs

  • value (DataType: Configurable) Transmits the current value of the variable. The data type matches the widget's configuration.

Custom Settings

The settings panel provides the following options:

  • Name: The unique name for the variable within your workflow (default: myVar).

    • How it works:
      • Used to reference the variable in other widgets.
      • To define a variable, type a name in the field and press Enter to save it.
      • Then, open the widget settings (gear icon) to choose the variable type (e.g., number, string) from the 'Type' menu.

  • Name Dropdown: When entering the variable name, a dropdown appears to help you select from existing variable names. This makes it easy to reuse or reference variables already defined in your workflow.

  • Type: Choose the kind of data the variable will store: String, Number, Array, Object, or Image. The type you select determines what kind of data the variable can store and what type the input/output ports will accept and transmit.

  • Default Value: Set an initial value for the variable. It will be used if no value is provided during workflow execution.

    • Note: The default value option is only available when the variable type is set to String or Number.

  • React to Value Changes (Reactive): Controls whether the variable widget automatically notifies other widgets of changes, or waits for a manual trigger to do so.

    • Enabled: The widget will transmit the new value to connected widgets every time it is updated (reactive mode).
    • Disabled: The widget will only output its value when explicitly triggered via the read input port (manual mode).

Variable Settings

 

📌 Important Notes

  • To test the example, make sure to save the username variable first. The flow won't run correctly unless the variable is saved.

 

Example

This example shows how a value can be stored in a Variable Widget and automatically updated in connected widgets using the "React to value changes" option.


Drag the example onto the workspace to explore and experiment!



In this example:

  1. The Button widget triggers the Text widget through the trigger port
  2. The Text widget transmits the string "Johnas" to the first Variable widget through the set port
  3. The first Variable widget stores the value in the userName variable and, because it's reactive, automatically transmits the value to the second Variable widget
  4. The second Variable widget receives the value and transmits it to the Text widget through the setText port for display

 

📌 Additional Notes

  • The Variable Widget is ideal for sharing state or values between widgets in a workflow
  • If the variable is set to reactive, it will automatically output its value when changed
  • The variable's type and default value can be configured in the settings
  • Use unique variable names to avoid conflicts in complex workflows

 

Glossary

  • Recipe

    A configuration file that defines a complete visual programming workflow, including all widgets, their connections, and settings.

  • Workflow

    A sequence of connected widgets that process data and perform actions in Kemu's visual programming environment.