Enum HandlerError 

pub enum HandlerError {
    Rendering(String),
    InvalidState(String),
    Invariant(String),
    MissingFragment(String),
    MissingData(String),
    TypeError(String),
    Protocol(ProtocolError),
    Evaluation(String),
    Io(Error),
    Writer(String),
    PluginData(String),
    ClientDisconnected,
    StreamTimeout,
    StreamingBoundary(Box<StreamingBoundaryError>),
    MissingStreamingBodyEnd,
    MissingStreamingHeadStart {
        before: &'static str,
    },
    DuplicateStreamingHeadStart,
}

Error types for the WebUI handler.

Variants

Rendering(String)

InvalidState(String)

Host-supplied state JSON could not be parsed or validated.

This is a caller input error, not a render failure. Bindings map it to their own state-error type, so it must stay distinguishable from HandlerError::Rendering without inspecting the message text.

Invariant(String)

MissingFragment(String)

MissingData(String)

TypeError(String)

Protocol(ProtocolError)

Evaluation(String)

Io(Error)

Writer(String)

PluginData(String)

ClientDisconnected

The HTTP client disconnected before the render completed.

Streaming ResponseWriter implementations return this from write() once their channel/socket is closed, so the handler can abort the render rather than do CPU work that has nowhere to go. Allocation-free (the variant carries no payload).

StreamTimeout

The streaming writer’s flush exceeded its configured deadline.

Indicates a slow/unresponsive consumer (slow-loris client, stuck proxy, etc.). The render thread is freed; downstream telemetry should distinguish this from ClientDisconnected so ops can alert on slow-client attacks.

StreamingBoundary(Box<StreamingBoundaryError>)

A streaming-boundary signal was malformed or arrived out of order.

The payload is boxed so this cold, streaming-only variant does not widen HandlerError — and therefore Result<(), HandlerError> threaded through the entire hot legacy render path — with two inline Strings.

MissingStreamingBodyEnd

A streaming render ended without its structural body_end signal.

MissingStreamingHeadStart

Streaming initialization cannot be emitted before document content.

Fields

before: &'static str

Structural point that made initialization too late.

DuplicateStreamingHeadStart

A malformed protocol emitted streaming initialization more than once.

Trait Implementations

impl Debug for HandlerError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for HandlerError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for HandlerError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for HandlerError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<ProtocolError> for HandlerError

fn from(source: ProtocolError) -> Self

Converts to this type from the input type.