Struct PredefinedConfigurationBuilder

pub struct PredefinedConfigurationBuilder { /* private fields */ }

Predefined Configuration Builder. See init for details.

Implementations

impl PredefinedConfigurationBuilder

pub fn set_prefix_env<K: ToString>(self, prefix: K) -> Self

Set environment prefix, default value if CFG. By default, following environment variables will be loaded in to configuration.

Environment Variable Regex Pattern: CFG_[0-9a-zA-Z]+

These are some predefined environment variables:

• CFG_ENV_PREFIX=CFG
• CFG_APP_NAME=app
• CFG_APP_DIR=
• CFG_APP_PROFILE=

You can change CFG to other prefix by this method.

pub fn set_dir<V: Into<PathBuf>>(self, path: V) -> Self

Set config file directory.

pub fn set_name<V: Into<String>>(self, name: V) -> Self

Set config file name.

pub fn set_profile<V: Into<String>>(self, profile: V) -> Self

Set config file profile.

pub fn set<K: Borrow<str>, V: Into<ConfigValue<'static>>>( self, key: K, value: V, ) -> Self

Set config into configuration by programming, or from command line arguments.

pub fn set_cargo_env(self, cargo: Cargo) -> Self

Set source from cargo build env. Macro init_cargo_env will collect all CARGO_PKG_* env variables, and CARGO_BIN_NAME into configuration.

Usage

use cfg_rs::*;
// Generate fn init_cargo_env().
init_cargo_env!();
let c = Configuration::with_predefined_builder()
  .set_cargo_env(init_cargo_env())
  .init()
  .unwrap();

pub fn set_init<F: FnOnce(&Configuration) -> Result<(), ConfigError> + 'static>( self, f: F, ) -> Self

Set init func, which will be run after env source loaded.

pub fn init(self) -> Result<Configuration, ConfigError>

Initialize configuration by multiple predefined sources.

Predefined Sources.

0. Cargo Package Env Variables (Must be explicitly set by set_cargo_env).
1. Customized by Programming or Commandline Args.¹
2. Random Value (Auto enabled with feature rand).
3. Environment Variable with Prefix CFG, referto set_prefix_env for details.¹
4. Profiled File Source with Path, ${app.dir}/${app.name}-${app.profile}.EXT. EXT: toml, json, yaml.²
5. File Source with Path, ${app.dir}/${app.name}.EXT. EXT: toml, json, yaml.²
6. Customized Source Can be Registered by register_source.

Crate Feature

• Feature rand to enable random value source.
• Feature toml to enable toml supports.
• Feature yaml to enable yaml supports.
• Feature json to enable json supports.

---

1. Always be enabled. ↩

2. See Supported File Formats for details. ↩