Trait Extractor 

pub trait Extractor<State> {
    type Error: Into<ExtractorError>;

    // Required method
    fn extract(
        frame: Frame,
        context: &Context<State>,
    ) -> Result<Self, Self::Error>
       where Self: Sized;

    // Provided method
    fn extract_from_frame_and_state(
        frame: Frame,
        context: &Context<State>,
    ) -> Result<Self>
       where Self: Sized,
             Self::Error: Into<ExtractorError> { ... }
}

Implement extract to allow for extracting values from an action.

Required Associated Types

type Error: Into<ExtractorError>

The error type for this extractor. Anything that can be converted into an extractor error can be used as an error type.

Types that can be converted into an extractor error are:

• String
• Infallible
• tower::BoxError

Required Methods

fn extract(frame: Frame, context: &Context<State>) -> Result<Self, Self::Error>

where Self: Sized,

Take an frame and a state and return a result containing the extracted value or the frame.

Provided Methods

fn extract_from_frame_and_state( frame: Frame, context: &Context<State>, ) -> Result<Self>

where Self: Sized, Self::Error: Into<ExtractorError>,

Extract a value from a frame and state, returning a result containing the extracted value or an error coerced into a crate::Error.

Implementations on Foreign Types

impl<State> Extractor<State> for ()

type Error = Infallible

fn extract(_: Frame, _: &Context<State>) -> Result<Self, Self::Error>

impl<State> Extractor<State> for String

type Error = ExtractorError

fn extract(frame: Frame, _: &Context<State>) -> Result<Self, Self::Error>

Implementors

impl<State> Extractor<State> for Frame

type Error = Infallible

impl<State> Extractor<State> for HttpGet

type Error = MessageFrameError

impl<State> Extractor<State> for HttpMeta

type Error = MessageFrameError

impl<State> Extractor<State> for HttpPost

type Error = MessageFrameError

impl<State> Extractor<State> for Message

type Error = MessageFrameError

impl<State> Extractor<State> for MessageData

type Error = MessageFrameError

impl<State> Extractor<State> for MessageMeta

type Error = MessageFrameError

impl<State> Extractor<State> for MessageUri

type Error = MessageFrameError

impl<State, T> Extractor<State> for Path<T>

where T: DeserializeOwned, State: Debug + Clone + Send + Sync + 'static,

type Error = PathError

impl<StateContents> Extractor<StateContents> for State<StateContents>

where StateContents: Clone + Send + Sync,

type Error = StateNotReadyError

impl<T, State> Extractor<State> for MessageJson<T>

where T: DeserializeOwned,

type Error = MessageFrameError

impl<T, State> Extractor<State> for MessageMetaJson<T>

where T: DeserializeOwned,

type Error = MessageFrameError