[−][src]Struct figment::Metadata
Metadata about a configuration value: its source's name and location.
Overview
Every Value
produced by a Figment
is Tag
ed with Metadata
by its producing Provider
. The metadata consists of:
- A name for the source, e.g. "TOML File".
- The
Source
itself, if it is known. - A default or custom interpolater.
This information is used to produce insightful error messages as well as to
generate values like RelativePathBuf
that know about their configuration
source.
Errors
Error
s produced by Figment
s contain the Metadata
for the value
that caused the error. The Display
implementation for Error
uses the
metadata's interpolater to display the path to the key for the value that
caused the error.
Interpolation
Interpolation takes a figment profile and key path (a.b.c
) and turns it
into a source-native path. The default interpolater returns a figment key
path prefixed with the profile if the profile is custom:
${profile}.${a}.${b}.${c}
Providers are free to implement any interpolater for their metadata. For
example, the interpolater for Env
uppercases each path key:
use figment::Metadata; let metadata = Metadata::named("environment variable(s)") .interpolater(|profile, path| { let keys: Vec<_> = path.iter() .map(|k| k.to_ascii_uppercase()) .collect(); format!("{}", keys.join(".")) }); let profile = figment::Profile::Default; let interpolated = metadata.interpolate(&profile, &["key", "path"]); assert_eq!(interpolated, "KEY.PATH");
Fields
name: Cow<'static, str>
The name of the configuration source for a given value.
source: Option<Source>
The source of the configuration value, if it is known.
Implementations
impl Metadata
[src]
pub fn from<N, S>(name: N, source: S) -> Self where
N: Into<Cow<'static, str>>,
S: Into<Source>,
[src]
N: Into<Cow<'static, str>>,
S: Into<Source>,
Creates a new Metadata
with the given name
and source
.
Example
use figment::Metadata; let metadata = Metadata::from("AWS Config Store", "path/to/value"); assert_eq!(metadata.name, "AWS Config Store"); assert_eq!(metadata.source.unwrap().custom(), Some("path/to/value"));
pub fn named<T: Into<Cow<'static, str>>>(name: T) -> Self
[src]
Creates a new Metadata
with the given name
and no source.
Example
use figment::Metadata; let metadata = Metadata::named("AWS Config Store"); assert_eq!(metadata.name, "AWS Config Store"); assert!(metadata.source.is_none());
pub fn source<S: Into<Source>>(self, source: S) -> Self
[src]
Sets the source
of self
to Some(source)
.
Example
use figment::Metadata; let metadata = Metadata::named("AWS Config Store").source("config/path"); assert_eq!(metadata.name, "AWS Config Store"); assert_eq!(metadata.source.unwrap().custom(), Some("config/path"));
pub fn interpolater<I: Clone + Send + Sync + 'static>(self, f: I) -> Self where
I: Fn(&Profile, &[&str]) -> String,
[src]
I: Fn(&Profile, &[&str]) -> String,
Sets the interpolater
of self
to the function f
. The interpolater
can be invoked via Metadata::interpolate()
.
Example
use figment::Metadata; let metadata = Metadata::named("environment variable(s)") .interpolater(|profile, path| { let keys: Vec<_> = path.iter() .map(|k| k.to_ascii_uppercase()) .collect(); format!("{}", keys.join(".")) }); let profile = figment::Profile::Default; let interpolated = metadata.interpolate(&profile, &["key", "path"]); assert_eq!(interpolated, "KEY.PATH");
pub fn interpolate<K: AsRef<str>>(
&self,
profile: &Profile,
keys: &[K]
) -> String
[src]
&self,
profile: &Profile,
keys: &[K]
) -> String
Runs the interpolater in self
on profile
and keys
.
Example
use figment::{Metadata, Profile}; let url = "ftp://config.dev"; let md = Metadata::named("Network").source(url) .interpolater(move |profile, keys| match profile.is_custom() { true => format!("{}/{}/{}", url, profile, keys.join("/")), false => format!("{}/{}", url, keys.join("/")), }); let interpolated = md.interpolate(&Profile::Default, &["key", "path"]); assert_eq!(interpolated, "ftp://config.dev/key/path"); let profile = Profile::new("static"); let interpolated = md.interpolate(&profile, &["key", "path"]); assert_eq!(interpolated, "ftp://config.dev/static/key/path");
Trait Implementations
impl Clone for Metadata
[src]
impl Debug for Metadata
[src]
impl Default for Metadata
[src]
impl PartialEq<Metadata> for Metadata
[src]
Auto Trait Implementations
impl !RefUnwindSafe for Metadata
impl Send for Metadata
impl Sync for Metadata
impl Unpin for Metadata
impl !UnwindSafe for Metadata
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
[src]
T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
[src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]
T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut T
[src]
impl<T> From<T> for T
[src]
impl<T, U> Into<U> for T where
U: From<T>,
[src]
U: From<T>,
impl<T> ToOwned for T where
T: Clone,
[src]
T: Clone,
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
[src]
pub fn clone_into(&self, target: &mut T)
[src]
impl<T, U> TryFrom<U> for T where
U: Into<T>,
[src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
[src]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
[src]
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
V: MultiLane<T>,