Function avalanche::hooks::vec

pub fn vec<'a, T: 'static, F: FnOnce() -> Vec<T>>(
    ctx: Context<'a>, 
    f: F
) -> (Tracked<&'a Vec<T>>, VecSetter<T>)

Like state, but returns a reference to a tracked::Vec.

Takes in a function F that returns a default Vec. The return value has fine-grained tracking: instead of only the whole vec being updated or not updated, each individual element is also tracked. For more information on how that works see tracked::Vec.

Note that vec returns a Tracked<tracked::Vec>, which is marked as updated if any of its children are updated. However, an individual element’s update status overrides this where appropriate.

Example

use avalanche::{component, tracked, View, vec};
use avalanche_web::components::{Div, H2, Button, Text};

#[component]
fn DynamicChildren() -> View {
    let (data, update_data) = vec(self, || vec!["child 1"]);
    let children = tracked!(data)
        .iter()
        .enumerate()
        .map(|(n, text)| Text!(key: n.to_string(), tracked!(text))).collect::<Vec<_>>();
 
    Div!([
        Button!(
            on_click: move |_| update_data.update(|data| data.push("another child")),
            child: Text!("+")
        ),
        Div!(tracked!(children))
    ])
}