Derive Macro Model 

#[derive(Model)]
{
    // Attributes available to this derive:
    #[state]
    #[init]
    #[update]
    #[view]
    #[model]
}

Derive macro for implementing the Model trait.

This macro generates a Model trait implementation that delegates to inherent methods named init, update, and view on your struct.

Requirements

• Applied to a named struct (not enum, union, tuple struct, or unit struct)
• Struct must implement init(&self) -> Option<Cmd> as an inherent method
• Struct must implement update(&mut self, msg: Message) -> Option<Cmd>
• Struct must implement view(&self) -> String

Field Attributes

• #[state] - Track field for change detection
• #[state(eq = "fn_name")] - Use custom equality function
• #[state(skip)] - Exclude from change detection
• #[state(debug)] - Log changes in debug builds

Example

use bubbletea::{Cmd, Message, Model};

#[derive(Model)]
struct Counter {
    #[state]
    count: i32,
}

impl Counter {
    fn init(&self) -> Option<Cmd> {
        None
    }

    fn update(&mut self, msg: Message) -> Option<Cmd> {
        if let Some(&delta) = msg.downcast_ref::<i32>() {
            self.count += delta;
        }
        None
    }

    fn view(&self) -> String {
        format!("Count: {}", self.count)
    }
}