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use std::marker::PhantomData;
use std::path::{Path, PathBuf};
use serde::de::{self, DeserializeOwned};
use crate::value::{Map, Dict};
use crate::{Error, Profile, Provider, Metadata};
#[derive(Debug, Clone)]
enum Source {
File(Option<PathBuf>),
String(String)
}
/// A `Provider` that sources values from a file or string in a given
/// [`Format`].
///
/// # Constructing
///
/// A `Data` provider is typically constructed indirectly via a type that
/// implements the [`Format`] trait via the [`Format::file()`] and
/// [`Format::string()`] methods which in-turn defer to [`Data::file()`] and
/// [`Data::string()`] by default:
///
/// ```rust
/// // The `Format` trait must be in-scope to use its methods.
/// use figment::providers::{Format, Data, Json};
///
/// // These two are equivalent, except the former requires the explicit type.
/// let json = Data::<Json>::file("foo.json");
/// let json = Json::file("foo.json");
/// ```
///
/// # Provider Details
///
/// * **Profile**
///
/// This provider does not set a profile.
///
/// * **Metadata**
///
/// This provider is named `${NAME} file` (when constructed via
/// [`Data::file()`]) or `${NAME} source string` (when constructed via
/// [`Data::string()`]), where `${NAME}` is [`Format::NAME`]. When
/// constructed from a file, the file's path is specified as file
/// [`Source`](crate::Source). Path interpolation is unchanged from the
/// default.
///
/// * **Data (Unnested, _default_)**
///
/// When nesting is _not_ specified, the source file or string is read and
/// parsed, and the parsed dictionary is emitted into the profile
/// configurable via [`Data::profile()`], which defaults to
/// [`Profile::Default`]. If the source is a file and the file is not
/// present, an empty dictionary is emitted.
///
/// * **Data (Nested)**
///
/// When nesting is specified, the source value is expected to be a
/// dictionary. It's top-level keys are emitted as profiles, and the value
/// corresponding to each key as the profile data.
#[derive(Debug, Clone)]
pub struct Data<F: Format> {
source: Source,
/// The profile data will be emitted to if nesting is disabled. Defaults to
/// [`Profile::Default`].
pub profile: Option<Profile>,
_format: PhantomData<F>,
}
impl<F: Format> Data<F> {
fn new(source: Source, profile: Option<Profile>) -> Self {
Data { source, profile, _format: PhantomData }
}
/// Returns a `Data` provider that sources its values by parsing the file at
/// `path` as format `F`. If `path` is relative, the file is searched for in
/// the current working directory and all parent directories until the root,
/// and the first hit is used.
///
/// Nesting is not enabled by default; use [`Data::nested()`] to enable
/// nesting.
///
/// ```rust
/// use serde::Deserialize;
/// use figment::{Figment, Jail, providers::{Format, Toml}, value::Map};
///
/// #[derive(Debug, PartialEq, Deserialize)]
/// struct Config {
/// numbers: Vec<usize>,
/// untyped: Map<String, usize>,
/// }
///
/// Jail::expect_with(|jail| {
/// jail.create_file("Config.toml", r#"
/// numbers = [1, 2, 3]
///
/// [untyped]
/// key = 1
/// other = 4
/// "#)?;
///
/// let config: Config = Figment::from(Toml::file("Config.toml")).extract()?;
/// assert_eq!(config, Config {
/// numbers: vec![1, 2, 3],
/// untyped: figment::util::map!["key".into() => 1, "other".into() => 4],
/// });
///
/// Ok(())
/// });
/// ```
pub fn file<P: AsRef<Path>>(path: P) -> Self {
fn find(path: &Path) -> Option<PathBuf> {
if path.is_absolute() {
match path.is_file() {
true => return Some(path.to_path_buf()),
false => return None
}
}
let cwd = std::env::current_dir().ok()?;
let mut cwd = cwd.as_path();
loop {
let file_path = cwd.join(path);
if file_path.is_file() {
return Some(file_path);
}
cwd = cwd.parent()?;
}
}
Data::new(Source::File(find(path.as_ref())), Some(Profile::Default))
}
/// Returns a `Data` provider that sources its values by parsing the string
/// `string` as format `F`. Nesting is not enabled by default; use
/// [`Data::nested()`] to enable nesting.
///
/// ```rust
/// use serde::Deserialize;
/// use figment::{Figment, Jail, providers::{Format, Toml}, value::Map};
///
/// #[derive(Debug, PartialEq, Deserialize)]
/// struct Config {
/// numbers: Vec<usize>,
/// untyped: Map<String, usize>,
/// }
///
/// Jail::expect_with(|jail| {
/// let source = r#"
/// numbers = [1, 2, 3]
/// untyped = { key = 1, other = 4 }
/// "#;
///
/// let config: Config = Figment::from(Toml::string(source)).extract()?;
/// assert_eq!(config, Config {
/// numbers: vec![1, 2, 3],
/// untyped: figment::util::map!["key".into() => 1, "other".into() => 4],
/// });
///
/// Ok(())
/// });
/// ```
pub fn string(string: &str) -> Self {
Data::new(Source::String(string.into()), Some(Profile::Default))
}
/// Enables nesting on `self`, which results in top-level keys of the
/// sourced data being treated as profiles.
///
/// ```rust
/// use serde::Deserialize;
/// use figment::{Figment, Jail, providers::{Format, Toml}, value::Map};
///
/// #[derive(Debug, PartialEq, Deserialize)]
/// struct Config {
/// numbers: Vec<usize>,
/// untyped: Map<String, usize>,
/// }
///
/// Jail::expect_with(|jail| {
/// jail.create_file("Config.toml", r#"
/// [global.untyped]
/// global = 0
/// hi = 7
///
/// [staging]
/// numbers = [1, 2, 3]
///
/// [release]
/// numbers = [6, 7, 8]
/// "#)?;
///
/// // Enable nesting via `nested()`.
/// let figment = Figment::from(Toml::file("Config.toml").nested());
///
/// let figment = figment.select("staging");
/// let config: Config = figment.extract()?;
/// assert_eq!(config, Config {
/// numbers: vec![1, 2, 3],
/// untyped: figment::util::map!["global".into() => 0, "hi".into() => 7],
/// });
///
/// let config: Config = figment.select("release").extract()?;
/// assert_eq!(config, Config {
/// numbers: vec![6, 7, 8],
/// untyped: figment::util::map!["global".into() => 0, "hi".into() => 7],
/// });
///
/// Ok(())
/// });
/// ```
pub fn nested(mut self) -> Self {
self.profile = None;
self
}
/// Set the profile to emit data to when nesting is disabled.
///
/// ```rust
/// use serde::Deserialize;
/// use figment::{Figment, Jail, providers::{Format, Toml}, value::Map};
///
/// #[derive(Debug, PartialEq, Deserialize)]
/// struct Config { value: u8 }
///
/// Jail::expect_with(|jail| {
/// let provider = Toml::string("value = 123").profile("debug");
/// let config: Config = Figment::from(provider).select("debug").extract()?;
/// assert_eq!(config, Config { value: 123 });
///
/// Ok(())
/// });
/// ```
pub fn profile<P: Into<Profile>>(mut self, profile: P) -> Self {
self.profile = Some(profile.into());
self
}
}
impl<F: Format> Provider for Data<F> {
fn metadata(&self) -> Metadata {
use Source::*;
match &self.source {
String(_) => Metadata::named(format!("{} source string", F::NAME)),
File(None) => Metadata::named(format!("{} file", F::NAME)),
File(Some(p)) => Metadata::from(format!("{} file", F::NAME), &**p)
}
}
fn data(&self) -> Result<Map<Profile, Dict>, Error> {
use Source::*;
let map: Result<Map<Profile, Dict>, _> = match (&self.source, &self.profile) {
(File(None), _) => return Ok(Map::new()),
(File(Some(path)), None) => F::from_path(&path),
(String(s), None) => F::from_str(&s),
(File(Some(path)), Some(prof)) => F::from_path(&path).map(|v| prof.collect(v)),
(String(s), Some(prof)) => F::from_str(&s).map(|v| prof.collect(v)),
};
Ok(map.map_err(|e| e.to_string())?)
}
}
/// Trait implementable by text-based [`Data`] format providers.
///
/// Instead of implementing [`Provider`] directly, types that refer to data
/// formats, such as [`Json`] and [`Toml`], implement this trait. By
/// implementing [`Format`], they become [`Provider`]s indirectly via the
/// [`Data`] type, which serves as a provider for all `T: Format`.
///
/// ```rust
/// use figment::providers::Format;
///
/// # use serde::de::DeserializeOwned;
/// # struct T;
/// # impl Format for T {
/// # type Error = serde::de::value::Error;
/// # const NAME: &'static str = "T";
/// # fn from_str<'de, T: DeserializeOwned>(_: &'de str) -> Result<T, Self::Error> { todo!() }
/// # }
/// # fn is_provider<T: figment::Provider>(_: T) {}
/// // If `T` implements `Format`, `T` is a `Provider`.
/// // Initialize it with `T::file()` or `T::string()`.
/// let provider = T::file("foo.fmt");
/// # is_provider(provider);
/// let provider = T::string("some -- format");
/// # is_provider(provider);
/// ```
///
/// [`Data<T>`]: Data
///
/// # Implementing
///
/// There are two primary implementation items:
///
/// 1. [`Format::NAME`]: This should be the name of the data format: `"JSON"`
/// or `"TOML"`. The string is used in the [metadata for `Data`].
///
/// 2. [`Format::from_str()`]: This is the core string deserialization method.
/// A typical implementation will simply call an existing method like
/// [`toml::from_str`]. For writing a custom data format, see [serde's
/// writing a data format guide].
///
/// The default implementations for [`Format::from_path()`], [`Format::file()`],
/// and [`Format::string()`] methods should likely not be overwritten.
///
/// [`NAME`]: Format::NAME
/// [serde's writing a data format guide]: https://serde.rs/data-format.html
pub trait Format: Sized {
/// The data format's error type.
type Error: de::Error;
/// The name of the data format, for instance `"JSON"` or `"TOML"`.
const NAME: &'static str;
/// Returns a `Data` provider that sources its values by parsing the file at
/// `path` as format `Self`. See [`Data::file()`] for more details. The
/// default implementation calls `Data::file(path)`.
fn file<P: AsRef<Path>>(path: P) -> Data<Self> {
Data::file(path)
}
/// Returns a `Data` provider that sources its values by parsing `string` as
/// format `Self`. See [`Data::string()`] for more details. The default
/// implementation calls `Data::string(string)`.
fn string(string: &str) -> Data<Self> {
Data::string(string)
}
/// Parses `string` as the data format `Self` as a `T` or returns an error
/// if the `string` is an invalid `T`. **_Note:_** This method is _not_
/// intended to be called directly. Instead, it is intended to be
/// _implemented_ and then used indirectly via the [`Data::file()`] or
/// [`Data::string()`] methods.
fn from_str<'de, T: DeserializeOwned>(string: &'de str) -> Result<T, Self::Error>;
/// Parses the file at `path` as the data format `Self` as a `T` or returns
/// an error if the `string` is an invalid `T`. The default implementation
/// calls [`Format::from_str()`] with the contents of the file. **_Note:_**
/// This method is _not_ intended to be called directly. Instead, it is
/// intended to be _implemented on special occasions_ and then used
/// indirectly via the [`Data::file()`] or [`Data::string()`] methods.
fn from_path<T: DeserializeOwned>(path: &Path) -> Result<T, Self::Error> {
let source = std::fs::read_to_string(path).map_err(de::Error::custom)?;
Self::from_str(&source)
}
}
#[allow(unused_macros)]
macro_rules! impl_format {
($name:ident $NAME:literal/$string:literal: $func:expr, $E:ty, $doc:expr) => (
#[cfg(feature = $string)]
#[cfg_attr(nightly, doc(cfg(feature = $string)))]
#[doc = $doc]
pub struct $name;
#[cfg(feature = $string)]
impl Format for $name {
type Error = $E;
const NAME: &'static str = $NAME;
fn from_str<'de, T: DeserializeOwned>(s: &'de str) -> Result<T, $E> {
$func(s)
}
}
);
($name:ident $NAME:literal/$string:literal: $func:expr, $E:ty) => (
impl_format!($name $NAME/$string: $func, $E, concat!(
"A ", $NAME, " [`Format`] [`Data`] provider.",
"\n\n",
"Static constructor methods on `", stringify!($name), "` return a
[`Data`] value with a generic marker of [`", stringify!($name), "`].
Thus, further use occurs via methods on [`Data`].",
"\n```\n",
"use figment::providers::{Format, ", stringify!($name), "};",
"\n\n// Source directly from a source string...",
"\nlet provider = ", stringify!($name), r#"::string("source-string");"#,
"\n\n// Or read from a file on disk.",
"\nlet provider = ", stringify!($name), r#"::file("path-to-file");"#,
"\n\n// Or configured as nested (via Data::nested()):",
"\nlet provider = ", stringify!($name), r#"::file("path-to-file").nested();"#,
"\n```",
"\n\nSee also [`", stringify!($func), "`] for parsing details."
));
)
}
#[cfg(feature = "yaml")]
#[cfg_attr(nightly, doc(cfg(feature = "yaml")))]
impl YamlExtended {
/// This "YAML Extended" format parser implements the draft ["Merge Key
/// Language-Independent Type for YAML™ Version
/// 1.1"](https://yaml.org/type/merge.html) spec via
/// [`serde_yaml::Value::apply_merge()`]. This method is _not_ intended to
/// be used directly but rather indirectly by making use of `YamlExtended`
/// as a provider. The extension is not part of any officially supported
/// YAML release and is deprecated entirely since YAML 1.2. Using
/// `YamlExtended` instead of [`Yaml`] enables merge keys, allowing YAML
/// like the following to parse with key merges applied:
///
/// ```yaml
/// tasks:
/// build: &webpack_shared
/// command: webpack
/// args: build
/// inputs:
/// - 'src/**/*'
/// start:
/// <<: *webpack_shared
/// args: start
/// ```
///
/// # Example
///
/// ```rust
/// use serde::Deserialize;
/// use figment::{Figment, Jail, providers::{Format, Yaml, YamlExtended}};
///
/// #[derive(Debug, PartialEq, Deserialize)]
/// struct Circle {
/// x: usize,
/// y: usize,
/// r: usize,
/// }
///
/// #[derive(Debug, PartialEq, Deserialize)]
/// struct Config {
/// circle1: Circle,
/// circle2: Circle,
/// circle3: Circle,
/// }
///
/// Jail::expect_with(|jail| {
/// jail.create_file("Config.yaml", r#"
/// point: &POINT { x: 1, y: 2 }
/// radius: &RADIUS
/// r: 10
///
/// circle1:
/// <<: *POINT
/// r: 3
///
/// circle2:
/// <<: [ *POINT, *RADIUS ]
///
/// circle3:
/// <<: [ *POINT, *RADIUS ]
/// y: 14
/// r: 20
/// "#)?;
///
/// let config: Config = Figment::from(YamlExtended::file("Config.yaml")).extract()?;
/// assert_eq!(config, Config {
/// circle1: Circle { x: 1, y: 2, r: 3 },
/// circle2: Circle { x: 1, y: 2, r: 10 },
/// circle3: Circle { x: 1, y: 14, r: 20 },
/// });
///
/// // Note that just `Yaml` would fail, since it doesn't support merge.
/// let config = Figment::from(Yaml::file("Config.yaml"));
/// assert!(config.extract::<Config>().is_err());
///
/// Ok(())
/// });
/// ```
pub fn from_str<'de, T: DeserializeOwned>(s: &'de str) -> serde_yaml::Result<T> {
let mut value: serde_yaml::Value = serde_yaml::from_str(s)?;
value.apply_merge()?;
T::deserialize(value)
}
}
impl_format!(Toml "TOML"/"toml": toml::from_str, toml::de::Error);
impl_format!(Yaml "YAML"/"yaml": serde_yaml::from_str, serde_yaml::Error);
impl_format!(Json "JSON"/"json": serde_json::from_str, serde_json::error::Error);
impl_format!(YamlExtended "YAML Extended"/"yaml": YamlExtended::from_str, serde_yaml::Error);