# fondant `fondant` is a macro based library to take the boilerplate out of configuration handling. Most of `fondant` is based off the `confy` crate. `fondant` adds a couple of extra features: - support for json, yaml and toml - support for custom config paths - support for custom config file names ### Sample usage ```rust // the struct has to derive Serialize, Deserialize and Default #[derive(Configure, Serialize, Deserialize, Default)] #[config_file = "config.toml"] // | // `-- this attribute sets the file name to "config.toml" // `-- the file format to "toml" // `-- the file path to "default" (read the notes below) struct AppConfig { version: u32, port: u32, username: String, } fn main() { // use `load` (associated method) to load the config file let mut conf = AppConfig::load().unwrap(); // do stuff with conf conf.version = 2; // call `store` to save changes conf.store().unwrap(); } ``` **Notes**: - `load` returns `Default::default` if the config file is not present, and stores a serialized `Default::default` at the specified path - the "default" config path varies by platform: * GNU/Linux: `$XDG_CONFIG_HOME/my_cool_crate/config.toml` (follows xdg spec) * MacOS: `$HOME/Library/Preferences/my_cool_crate/config.toml` * Windows: `{FOLDERID_RoamingAppData}\_project_path_\config` ### Customization Set your own filename, for ex.: `apprc` ```rust #[derive(Configure, Serialize, Deserialize, Default)] #[config_file = "apprc.toml"] struct AppConfig { // -- snip -- } // effective path: $XDG_CONFIG_HOME/my_cool_crate/apprc.toml // effective format: toml ``` Change file format to `yaml`, by changing the file extension. Supported extensions are `yaml`, `toml`, `json`: ```rust #[derive(Configure, Serialize, Deserialize, Default)] #[config_file = "config.yaml"] struct AppConfig { // -- snip -- } // effective path: $XDG_CONFIG_HOME/my_cool_crate/config.yaml // effective format: yaml ``` Override the default config path, for ex.: the home directory (it is not recommended to override config path): ```rust #[derive(Configure, Serialize, Deserialize, Default)] #[config_file = "~/.apprc.json"] struct AppConfig { // -- snip -- } // effective path: $HOME/.apprc.json // effective format: json ``` Fondant meshes well with Serde, for ex.: ```rust #[derive(Configure, Serialize, Deserialize, Default)] #[config_file = "config.toml"] struct Madagascar { #[serde(skip)] rating: u32, name: String, penguins: u32, } ``` Above snippet produces this config file: ```toml name = 'Central Park Zoo' penguins = 4 ``` ### todo - [ ] improve error from trait impl - [ ] use `syn::Error` and `syn::Result` to report macro errors - [x] write docs - [ ] bundle and publish to crates.io