Struct RegisteredConstructor 

pub struct RegisteredConstructor<'a> { /* private fields */ }

A constructor registered via Blueprint::constructor.

Example

You can use the methods exposed by RegisteredConstructor to tune the behaviour of the registered constructor type. For example, instruct Pavex to clone the constructed type if it’s necessary to satisfy the borrow checker:

use pavex::{methods, Blueprint};

pub struct Pool {
    // [...]
}

#[methods]
impl Pool {
    #[singleton]
    pub fn new(config: &PoolConfig) -> Self {
        // [...]
    }
}

let mut bp = Blueprint::new();
// This is equivalent to `#[singleton(clone_if_necessary)]`
bp.constructor(POOL_NEW).clone_if_necessary();

Example: override the annotation

You can also override the behaviour specified via the singleton attribute.

use pavex::{methods, Blueprint};

pub struct Pool {
    // [...]
}

#[methods]
impl Pool {
    #[singleton(clone_if_necessary)]
    pub fn new(config: &PoolConfig) -> Self {
        // [...]
    }
}

let mut bp = Blueprint::new();
// Using `never_clone` here, we are overriding the `clone_if_necessary`
// flag specified via the `singleton` attribute.
// This is equivalent to `#[singleton]`, thus restoring
// the default behaviour.
bp.constructor(POOL_NEW).never_clone();

Implementations

impl RegisteredConstructor<'_>

pub fn error_handler(self, error_handler: ErrorHandler) -> Self

Register an error handler.

If an error handler has already been registered for this constructor, it will be overwritten.

Guide

Check out the “Error handlers” section of Pavex’s guide for a thorough introduction to error handlers in Pavex applications.

Example

use pavex::Blueprint;
use pavex::Response;
use pavex::{methods, transient};

// 👇 a fallible constructor
#[transient]
pub fn logger() -> Result<Logger, ConfigurationError> {
    // [...]
}

#[methods]
impl ConfigurationError {
    #[error_handler]
    fn to_response(
        #[px(error_ref)] &self,
        log_level: LogLevel,
    ) -> Response {
        // [...]
    }
}

let mut bp = Blueprint::new();
bp.constructor(LOGGER)
    .error_handler(CONFIGURATION_ERROR_TO_RESPONSE);

pub fn lifecycle(self, lifecycle: Lifecycle) -> Self

Change the constructor lifecycle.

pub fn cloning(self, strategy: CloningPolicy) -> Self

Set the cloning strategy for the output type returned by this constructor.

By default, Pavex will never try to clone the output type returned by a constructor. If the output type implements Clone, you can change the default by invoking clone_if_necessary: Pavex will clone the output type if it’s necessary to generate code that satisfies Rust’s borrow checker.

pub fn clone_if_necessary(self) -> Self

Set the cloning strategy to CloningPolicy::CloneIfNecessary. Check out cloning method for more details.

pub fn never_clone(self) -> Self

Set the cloning strategy to CloningPolicy::NeverClone. Check out cloning method for more details.

pub fn allow(self, lint: Lint) -> Self

Silence a specific Lint for this constructor.

pub fn warn(self, lint: Lint) -> Self

Emit a warning if a specific Lint triggers for this constructor.

pub fn deny(self, lint: Lint) -> Self

Fail the build if a specific Lint triggers for this constructor.