Function ShowMessage 

pub fn ShowMessage(
    Severity: MessageSeverity,
    Message: String,
    OptionsValue: Value,
) -> ActionEffect<Arc<dyn UserInterfaceProvider>, CommonError, Option<String>>

Creates an effect that, when executed, will display a message to the user with a given severity and a set of optional action buttons.

It uses the UserInterfaceProvider capability from the environment to perform the operation, which typically involves sending an event to the frontend and waiting for the user’s interaction.

Parameters

• Severity: The MessageSeverity of the message (Info, Warning, Error).
• Message: The primary text content of the message.
• OptionsValue: A serde_json::Value representing the MessageOptionsDTO, which can include a title, detail text, and a list of action buttons.

Returns

An ActionEffect that resolves with an Option<String>, containing the string title of the action button the user clicked, or None if the message was dismissed without an action.