# More Configuration   ![CI][ci-badge] [![Crates.io][crates-badge]][crates-url] [![MIT licensed][mit-badge]][mit-url]
[crates-badge]: https://img.shields.io/crates/v/more-config.svg
[crates-url]: https://crates.io/crates/more-config
[mit-badge]: https://img.shields.io/badge/license-MIT-blueviolet.svg
[mit-url]: https://github.com/commonsensesoftware/more-rs-config/blob/main/LICENSE
[ci-badge]: https://github.com/commonsensesoftware/more-rs-config/actions/workflows/ci.yml/badge.svg
More Configuration is a configuration library for Rust.
You may be looking for:
- [User Guide](https://commonsensesoftware.github.io/more-rs-config)
- [API Documentation](https://docs.rs/more-config)
- [Release Notes](https://github.com/commonsensesoftware/more-rs-config/releases)
## Features
This crate provides the following features:
- _default_ - Abstractions for configuration, including the **std** features
- **std** - Standard configuration implementation
- **all** - Includes all features, except **async**
- **async** - Use configuration in an asynchronous context
- **mem** - An in-memory configuration source
- **env** - An environment variables configuration source
- **cmd** - A command-line argument configuration source
- **json** - A \*.json file configuration source
- **xml** - A \*.xml file configuration source
- **ini** - An \*.ini file configuration source
- **chained** - Chain multiple configuration sources
- **binder** - Bind a configuration to strongly-typed values and structs
>Use `--features all,async` for all features with asynchronous support
## Configuration in Action
Consider the following `demo.json` file:
```json
{
"text": "Hello world!",
"demo": true,
"clients": [{
"region": "us-west",
"url": "https://tempuri.org"
}]
}
```
The configuration can be loaded, merged, and accessed from multiple sources:
```rust
use config::{*, ext::*};
fn main() {
let config = DefaultConfigurationBuilder::new()
.add_in_memory(&[("Demo", "false")])
.add_json_file("demo.json".is().optional())
.add_env_vars()
.add_command_line()
.build()
.unwrap();
if let Some(demo) = config.get("demo") {
if demo.as_str() == "true" {
println!("{}", config.get("Text").unwrap().as_str());
println!("{}", config.get("Clients:0:Region").unwrap().as_str());
return;
}
}
println!("Not a demo!");
}
```
Raw configuration values can be used, but they are much more interesting when we data bind them to strongly-typed values:
```rust
use serde::Deserialize;
#[derive(Default, Deserialize)]
#[serde(rename_all(deserialize = "PascalCase"))]
struct Client {
region: String,
url: String,
}
#[derive(Default, Deserialize)]
#[serde(rename_all(deserialize = "PascalCase"))]
struct AppOptions {
text: String,
demo: bool,
clients: Vec<Client>,
}
```
>The first letter of JSON configuration keys are normalized to uppercase.
```rust
use config::{*, ext::*};
fn main() {
let file = std::env::current_exe()
.unwrap()
.parent()
.unwrap()
.join("../../demo.json");
let config = DefaultConfigurationBuilder::new()
.add_json_file(file)
.build()
.unwrap();
let app: AppOptions = config.reify();
if app.demo {
println!("{}", &app.text);
println!("{}", &app.clients[0].region);
return;
}
println!("Not a demo!");
}
```
## Minimum Supported Rust Version
When increasing the minimum supported Rust version (MSRV), the new version must have been released
at least six months ago. The current MSRV is 1.60.
## License
This project is licensed under the [MIT license].
[MIT license]: https://github.com/commonsensesoftware/more-rs-config/blob/main/LICENSE