Trait abscissa_core::component::Component

pub trait Component<A>: AsAny + Debug + Send + Syncwhere
    A: Application,{
    fn id(&self) -> Id;
    fn version(&self) -> Version;

    fn after_config(&mut self, config: &A::Cfg) -> Result<(), FrameworkError> { ... }
    fn dependencies(&self) -> Iter<'_, Id> { ... }
    fn register_dependency(
        &mut self,
        handle: Handle,
        dependency: &mut dyn Component<A>
    ) -> Result<(), FrameworkError> { ... }
    fn before_shutdown(&self, kind: Shutdown) -> Result<(), FrameworkError> { ... }
}

Application components.

Components are Abscissa’s primary extension mechanism, and are aware of the application lifecycle. They are owned by the application as boxed trait objects in a runtime type registry which is aware of a dependency ordering and can (potentially in the future) support runtime reinitialization.

During application initialization, callbacks are sent to all components upon events like application configuration being loaded. The register_dependency callback is called for each dependency returned by the dependencies method.

Additionally, they receive a callback prior to application shutdown.

Custom Derive

The main intended way to impl this trait is by using the built-in custom derive functionality.

use abscissa_core::Component;

#[derive(Component, Debug)]
pub struct MyComponent {}

This will automatically implement the entire trait for you.

Required Methods

fn id(&self) -> Id

Identifier for this component.

These are the Rust path (e.g. crate_name:foo::Foo) by convention.

fn version(&self) -> Version

Version of this component

Provided Methods

fn after_config(&mut self, config: &A::Cfg) -> Result<(), FrameworkError>

Lifecycle event called when application configuration should be loaded if it were possible.

fn dependencies(&self) -> Iter<'_, Id>

Names of the components this component depends on.

After this app’s after_config callback is fired, the register_dependency callback below will be fired for each of these.

fn register_dependency(
    &mut self,
    handle: Handle,
    dependency: &mut dyn Component<A>
) -> Result<(), FrameworkError>

Register a dependency of this component (a.k.a. “dependency injection”)

fn before_shutdown(&self, kind: Shutdown) -> Result<(), FrameworkError>

Perform any tasks which should occur before the app exits

Trait Implementations

impl<A> PartialEq<Box<dyn Component<A> + 'static, Global>> for Box<dyn Component<A>>where
    A: Application,

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<A> PartialOrd<Box<dyn Component<A> + 'static, Global>> for Box<dyn Component<A>>where
    A: Application,

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

Implementors

impl<A> Component<A> for Terminalwhere
    A: Application,

impl<A> Component<A> for Tracingwhere
    A: Application,