Struct EnvSource 

pub struct EnvSource<R: EnvReader = RealEnv> { /* private fields */ }

Collect input from an environment variable.

This source reads from an environment variable. It is available when the variable is set and non-empty.

Example

use standout_input::{InputChain, ArgSource, EnvSource};

// For: MY_TOKEN=secret myapp
let chain = InputChain::<String>::new()
    .try_source(ArgSource::new("token"))
    .try_source(EnvSource::new("MY_TOKEN"));

Testing

Use EnvSource::with_reader to inject a mock for testing:

use standout_input::{EnvSource, MockEnv};

let env = MockEnv::new().with_var("MY_TOKEN", "secret");
let source = EnvSource::with_reader("MY_TOKEN", env);

Implementations

impl EnvSource<RealEnv>

pub fn new(var_name: impl Into<String>) -> Self

Create a new environment variable source.

impl<R: EnvReader> EnvSource<R>

pub fn with_reader(var_name: impl Into<String>, reader: R) -> Self

Create an environment source with a custom reader.

This is primarily used for testing to inject mock environment.

pub fn var_name(&self) -> &str

Get the environment variable name.

Trait Implementations

impl<R: Clone + EnvReader> Clone for EnvSource<R>

fn clone(&self) -> EnvSource<R>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<R: EnvReader + 'static> InputCollector<String> for EnvSource<R>

fn name(&self) -> &'static str

Human-readable name for this collector.

fn is_available(&self, _matches: &ArgMatches) -> bool

Check if this collector can provide input in the current environment.

fn collect(&self, _matches: &ArgMatches) -> Result<Option<String>, InputError>

Attempt to collect input from this source.

fn validate(&self, _value: &T) -> Result<(), String>

Validate the collected value.

fn can_retry(&self) -> bool

Whether this collector supports retry on validation failure.