Universal JSON support in warmy-0.11.1

warmy, universal, json
Fri Jan 25 00:50:00 2019 UTC, by Dimitri Sabadie — feed

Norbert the hot-dog

I just added a new feature to warmy to make it more accessible and easy to use. It concerns JSON and serde.

Universal JSON support in warmy 0.11.1

If you’ve been using warmy a bit, you might be used to its traits and structures, like Load, Loaded, Load::reload, Res, etc. All those concepts are mandatory to implement loading, reloading and scarce resource sharing. Since version 0.7, warmy has got loading and reloading methods. That feature enables you to have several impl for the same type of resource by changing the method used to load. The default is () but you’re free to use any you want. The idea is that you can call the Store::get_by or Store::get_proxied_by methods to specify which method to use explicitly when loading and reloading a given resource.

warmy 0.11.1 uses that concept to provide a universal implementor for anything that implements the Deserialize trait from serde. Basically, once your type implements Deserialize, you can load and hot-reload values of this type by using the Json type from warmy.

Universal JSON implementors are available only if the "json" feature is enabled in warmy. It’s the case by default. Feel free to use default-features = false if you don’t want it.

Here’s a short example of what it looks like to load and hot-reload a Dog using the universal JSON feature:

use serde::Deserialize;
use warmy::{Res, SimpleKey, Store, StoreOpt};
use warmy::json::Json;
use std::thread::sleep;
use std::time::Duration;

#[derive(Debug, Deserialize)]
#[serde(rename_all = "snake_case")]
struct Dog {
  name: String,
  gender: Gender

#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq)]
#[serde(rename_all = "snake_case")]
enum Gender {

fn main() {
  let mut store: Store<(), SimpleKey> = Store::new(StoreOpt::default()).unwrap();
  let ctx = &mut ();

  let resource: Result<Res<Dog>, _> = store.get_by(&SimpleKey::from_path("/dog.json"), ctx, Json);

  match resource {
    Ok(dog) => {
      loop {

        println!("Dog is {} and is a {:?}", dog.borrow().name, dog.borrow().gender);

    Err(e) => eprintln!("{}", e)

This feature should help people adopt the crate and use it without worrying too much about the actual implementation of Load.

If you’re interested in adding other methods, like YAML, XML or whatever, feel free to open a PR on GitHub! I’ll be very happy to accept it. More documentation about the feature can be found in the README or the online documentation.

Keep the vibes.