Setting default store values

The best way to define the default value of your store is by manually implementing Default.

#![allow(unused)]
fn main() {
extern crate yewdux;
use yewdux::prelude::*;
#[derive(PartialEq, Store)]
struct MyStore {
    foo: String,
    bar: String,
}

impl Default for MyStore {
    fn default() -> Self {
        Self {
            foo: "foo".to_string(),
            bar: "bar".to_string(),
        }
    }
}
}

Sometimes you may need additional context to set the initial value of your store. To do this, there are a couple options.

You can set the value at the beginning of your application, before your app renders (like in your main function).

extern crate yewdux;
use yewdux::prelude::*;
#[derive(PartialEq, Store, Default)]
struct MyStore {
    foo: String,
    bar: String,
}
fn main() {
    // Construct foo and bar however necessary
    let foo = "foo".to_string();
    let bar = "bar".to_string();
    // Run this before starting your app.
    Dispatch::<MyStore>::global().set(MyStore { foo, bar });
    // ... continue with your app setup
}

You can also set the inital value from a function component. The use_effect_with hook can be used to run the hook only once (just be sure to use empty deps).

#![allow(unused)]
fn main() {
extern crate yew;
extern crate yewdux;

use yewdux::prelude::*;
use yew::prelude::*;
#[derive(PartialEq, Store, Default)]
struct MyStore {
    foo: String,
    bar: String,
}
#[function_component]
fn MyComponent() -> Html {
    let dispatch = use_dispatch::<MyStore>();
    // This runs only once, on the first render of the component.
    use_effect_with(
        (), // empty deps
        move |_| {
            // Construct foo and bar however necessary
            let foo = "foo".to_string();
            let bar = "bar".to_string();
            dispatch.set(MyStore { foo, bar });
            || {}
        },
    );

    html! {
        // Your component html
    }
}
}

Keep in mind your store will still be initialized with Store::new (usually that's set to Default::default()), however this is typically inexpensive.