Declare UIs with Declarative API

Panel is built on Param - a library for handling all the user-modifiable parameters, arguments, and attributes that control your code. This section contains how-to guides for using Param objects and declared dependencies to generate user interfaces with Panel.

Generate Widgets from Parameters

How to generate UIs from Parameterized classes without writing any GUI related code.

Generate Widgets from Parameters

Declare Custom Widgets

How to extend Param based UIs with custom widgets.

Declare Custom Widgets

Declare Parameter dependencies

How to leverage @param.depends to express dependencies and trigger events based on UI interactions.

Declare parameter dependencies

Create nested UIs

How to structure Parameterized classes with subobjects to create nested UIs automatically.

Create nested UIs

Examples

Action Button

Using param.Action to define a UI with a button.

param.Action Example

Automatic Loading Indicator

Automatically enable a loading indicator for components rendered dynamically.

Loading Indicator

Param Subobjects

Using Param to express a nested UI using a hierarchy of classes.

Param Subobjects

Precedence

Using Parameter precedence to control the visibility of components.

Param Precedence