#observer #events #observable #pointers #data #immutability #mutable

simple-observable

Simple observable pointer for mutable and immutable data

5 releases

0.2.2 Feb 11, 2022
0.2.1 Feb 11, 2022
0.2.0 Feb 11, 2022
0.1.1 Feb 9, 2022
0.1.0 Feb 9, 2022

#1535 in Data structures

MIT license

4KB

Simple Observable

This simple library is made to notify you when your data changes

Adding a dependency: simple-observable = "0.2.2"

Changing observed values

use simple_observable::Observable;

fn main() {
    let a = 1;
    println!("Initial value: {}", a);
    let mut obs1 = Observable::new(a);
    obs1.add_listener(listener1);
    obs1.add_listener(listener2);
    obs1.add_listener(listener3);
    obs1.change(my_change_function);
}

fn my_change_function(num: &mut i32) {
    *num += 1;
}

fn listener1(num: &i32) {
    println!("(listener1) New value after change: {}", num);
}

fn listener2(num: &i32) {
    println!("(listener2) New value after change: {}", num);
}

fn listener3(num: &i32) {
    println!("(listener3) New value after change: {}", num);
}

Observable is a pointer that can be dereferenced and the data can be accessed directly. However, the data cannot be changed, but only read

It is important to understand that the Observable owns the data and the only way to change the data is to call the change() method.

No runtime deps