Yewstand

Zustand-inspired state management for Yew - Simple, declarative global stores using Rust macros.

Features

• Global Store: Single source of truth with automatic React-like re-renders
• Shallow Selectors: Subscribe only to specific fields for optimal performance
• Mutation Macros: Generate store-updating methods from simple functions
• Zero-boilerplate hooks: use_app_store() and use_app_store_shallow()
• Async Support: Mutations can be async functions

Quick Start

cargo add yew --features="csr"
cargo add yewstand

use yewstand::{yewstand_store, yewstand_mutations};

// 1. Define your store
#[derive(Default, Clone, PartialEq)]
#[yewstand_store]
pub struct AppStore {
    pub count: i32,
    pub name: String,
}

// 2. Define mutations
#[yewstand_mutations]
impl AppStore {
    pub fn set_count(state: AppStore, value: i32) -> AppStore {
        AppStore { count: value, ..state }
    }
    
    pub async fn load_count(state: AppStore, id: String) -> AppStore {
        let count = get_count_from_backend().await;
        AppStore { count, ..state }
    }
}

// 3. Use in components
#[function_component(App)]
fn app() -> Html {
    let store = use_app_store(); // Full store subscription
    let count = *use_app_store_shallow(|s| s.count); // Shallow selector
    
    let onclick = {
        Callback::from(|_| {
            AppStore::set_count(42); // Updates global store automatically
        })
    };
    
    html! {
        <>
            <p>{ format!("Count: {}", count) }</p>
            <p>{ format!("Name: {}", store.name) }</p>
            <button onclick={onclick}>{ "Set to 42" }</button>
        </>
    }
}

API Reference

Store Macro: #[yewstand_store]

Automatically generates:

• use_app_store() - Full store hook
• use_app_store_shallow(|store| value) - Shallow selector hook
• update_store(|store| {...}) - Functional updater
• Global store infrastructure

Requirements: Store must implement Default, Clone, PartialEq

Mutations Macro: #[yewstand_mutations]

Transform functions like this:

pub fn set_count(state: AppStore, value: i32) -> AppStore {
    AppStore { count: value, ..state }
}

Into callable methods:

AppStore::set_count(42); // Updates global store automatically

Pattern: (state: AppStore, args...) -> AppStore

Examples

See the counter example for a complete working demo with:

• Full store subscription (FullStore component)
• Shallow selector (CountOnly component)
• Functional updates (update_store)
• Generated mutations (AppStore::set_count)

License

Unlicense