Struct BeforeSend 

pub struct BeforeSend<H>(pub H);

Run a [trillium::Handler] in before_send

Wrap a handler with this type to call its run callback in before_send allowing it to execute even if the conn has been halted. Note that it will be called later in the handler sequence as a result of this.

Tuple Fields

0: H

Trait Implementations

impl<H: Debug> Debug for BeforeSend<H>

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

Formats the value using the given formatter.

impl<H> Handler for BeforeSend<H>

where H: Handler, Self: Send + Sync + 'static,

async fn run(&self, conn: Conn) -> Conn

Executes this handler, performing any modifications to the Conn that are desired.

async fn init(&mut self, info: &mut Info)

Performs one-time async set up on a mutable borrow of the Handler before the server starts accepting requests. This allows a Handler to be defined in synchronous code but perform async setup such as establishing a database connection or fetching some state from an external source. This is optional, and chances are high that you do not need this.

async fn before_send(&self, conn: Conn) -> Conn

Performs any final modifications to this conn after all handlers have been run. Although this is a slight deviation from the simple conn->conn->conn chain represented by most Handlers, it provides an easy way for libraries to effectively inject a second handler into a response chain. This is useful for loggers that need to record information both before and after other handlers have run, as well as database transaction handlers and similar library code.

fn name(&self) -> Cow<'static, str>

Customize the name of your handler. This is used in Debug implementations. The default is the type name of this handler.

fn has_upgrade(&self, upgrade: &Upgrade) -> bool

predicate function answering the question of whether this Handler would like to take ownership of the negotiated Upgrade. If this returns true, you must implement [Handler::upgrade]. The first handler that responds true to this will receive ownership of the [trillium::Upgrade][crate::Upgrade] in a subsequent call to [Handler::upgrade]

async fn upgrade(&self, upgrade: Upgrade)

This will only be called if the handler reponds true to [Handler::has_upgrade] and will only be called once for this upgrade. There is no return value, and this function takes exclusive ownership of the underlying transport once this is called. You can downcast the transport to whatever the source transport type is and perform any non-http protocol communication that has been negotiated. You probably don’t want this unless you’re implementing something like websockets. Please note that for many transports such as TcpStreams, dropping the transport (and therefore the Upgrade) will hang up / disconnect.