Struct RegisteredConfig 

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

A configuration type registered via Blueprint::config.

Example

You can use the methods exposed by RegisteredConfig to tune the behaviour of the registered configuration type. For example, instruct Pavex to use the Default implementation if the user configuration doesn’t specify a value for pool:

use pavex::{config, Blueprint};

#[config(key = "pool")]
#[derive(serde::Deserialize, Debug, Clone)]
pub struct PoolConfig {
    pub max_n_connections: u32,
    pub min_n_connections: u32,
}

impl Default for PoolConfig {
    fn default() -> Self {
        Self {
            max_n_connections: 10,
            min_n_connections: 2,
        }
    }
}

let mut bp = Blueprint::new();
// This is equivalent to `#[config(key = "pool", default_if_missing)]`
bp.config(POOL_CONFIG).default_if_missing();

Example: override the annotation

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

use pavex::{config, Blueprint};

#[config(key = "pool", default_if_missing)]
#[derive(serde::Deserialize, Debug, Clone)]
pub struct PoolConfig {
    pub max_n_connections: u32,
    pub min_n_connections: u32,
}

let mut bp = Blueprint::new();
// Using `required`, we are overriding the `default_if_missing` flag
// specified via the `config` attribute.
// This is equivalent to `#[config(key = "pool")]`, thus restoring
// the default behaviour.
bp.config(POOL_CONFIG).required();

Implementations

impl RegisteredConfig<'_>

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

Set the cloning strategy for this configuration type.

By default, Pavex will clone a configuration type if it’s necessary to generate code that satisfies Rust’s borrow checker. You can change the default behaviour by invoking never_clone.

Regardless of the chosen strategy, configuration types must implement Clone, since the code-generated ApplicationConfig type will need to derive it.

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 default_if_missing(self) -> Self

Use the default configuration values returned by Default::default if the user has not specified its own configuration for this type.

Requirements

The configuration type must implement the Default trait to support this option.

Implementation notes

default_if_missing adds a #[serde(default)] attribute on the corresponding configuration key in the code-generated ApplicationConfig struct.

pub fn required(self) -> Self

Force the user to specify a value for this configuration entry.

It’s the opposite of default_if_missing.

pub fn include_if_unused(self) -> Self

Include this configuration entry in the generated ApplicationConfig struct even if the type is never used by the application.