Easy-to-use asset manager for many environments.

Goals

This crate is written with following goals in mind:

• Batteries included.
  Crate comes with variety of simple data sources like FileSource and HttpSource. Few Formats based on serde are included under feature flags.
  More Sources and Formats can be added.

• Extensibility.
  Multiple Format traits can be implemented for any asset type, including foreign asset types.
  For example JsonFormat, YamlFormat and RonFormat (bundled in the crate) implement Format trait for any asset type which intermediate representation implements serde::de::DeserializeOwned.

• Supporting WebAssembly.
  All mandatory dependencies are WASM-compatible and no threading is required for asset loading to work.

• Working with asynchronous data sources.
  All data sources must implement Source trait. Source::read method returns future that will be driven to completion by the bound executor - see Spawn.

• no_std
  But alloc is required.

• Fast compilation.
  build after cargo clean takes ~3s.

Non-Goals

This crate is not aimed to support every possible feature. Here's list of some of those features:

• Hot-reloading
  Currently there are no plans to support hot-reloading.

Features

All out-of-the-box functionality exept core traits and types can be enabled with features.

General

• std - adds implementation of std::error::Error trait for error types. Enabled by default.
• sync - makes most types MaybeSend and some MaybeSync. Adds requirements for traits implementations to be MaybeSend and MaybeSync where needed. Enabled by default.

Sources

• fs (enables std) - adds FileSource - Source implementation that loads asset bytes from file-system.
• reqwest - adds ReqwestSource - Source implementation that loads asset bytes from URLs using reqwest. Using this source requires spawner to spawn tasks with tokio. Otherwise reqwest interals will panic.
• fetch - adds FetchSource that uses browser's Fetch API to load assets data. Conflicts with sync feature.

Formats

• json-format - adds JsonFormat - Format implementation that treats asset bytes as JSON document and deserializes asset representation via serde
• yaml-format - adds YamlFormat - Format implementation that treats asset bytes as YAML document and deserializes asset representation via serde
• ron-format - adds RonFormat - Format implementation that treats asset bytes as RON document and deserializes asset representation via serde

Spawners

• futures-spawn - adds Spawn implementation for futures_task::Spawn(aka futures::task::Spawn) allowing to use compatible spawners to drive loading tasks to completion.
• wasm-bindgen-spawn - adds Spawn implementations that uses wasm_bindgen_futures::spawn_local to drive loadin tasks. Usable only on wasm32 target.
• tokio-spawn - adds Spawn implementation for goods::Tokio(tokio::runtime::Handle wrapper) allowing tokio to drive loading tasks. ReqwestSource requires tokio runtime.