Crate di 

More Dependency Injection  

More DI is a dependency injection (DI) library for Rust. A trait or struct can be used as the injected type.

You may be looking for:

• User Guide
• API Documentation
• Release Notes

Features

This crate provides the following features:

• default - Abstractions for dependency injection, plus the builder and inject features
• builder - Functions for configuring service descriptors
• async - Use dependencies in an asynchronous context
• inject - Code-generate common injection scenarios
• lazy - Lazy-initialize service resolution
• fmt - Additional output formatting
• alias - Use alternate type aliases

Supported Lifetimes

A service can have the following lifetimes:

• Transient - a new instance is created every time it is requested
• Singleton - a single, new instance is created the first time it is requested
• Scoped - a new instance is created once per provider that it is requested from

Dependency Injection in Action

Consider the following traits and structures. After they ar defined, the information can be composed into a simple application.

Proc macro attributes are not required, but they are the fastest and simplest approach to add DI in your applications.

use di::*;
use std::rc::Rc;

trait Phrase {
    fn salutation(&self) -> &str;
}

#[injectable(Phrase)]
struct EnglishPhrase;

impl Phrase for EnglishPhrase {
    fn salutation(&self) -> &str {
        "Hello world!"
    }
}

#[injectable]
struct Person {
    phrase: Rc<dyn Phrase>,
}

impl Person {
    fn speak(&self) -> &str {
        self.phrase.salutation()
    }
}

fn main() {
    let provider = ServiceCollection::new()
        .add(EnglishPhrase::singleton())
        .add(Person::transient())
        .build_provider()
        .unwrap();

    let person = provider.get_required::<Person>();

    println!("{}", person.speak());
}

License

This project is licensed under the MIT license.

Modules

lazy

Contains support for lazy service resolution.

Structs

Activator

Represents an activator for a service instance.

InjectBuilder

Represents the builder for an injected type.

KeyedRef

Represents a holder for a keyed service.

ScopedServiceProvider

Represents a scoped ServiceProvider.

ServiceCollection

Represents a service collection.

ServiceDependency

Represents a service dependency.

ServiceDescriptor

Represents the description of a service with its service type, implementation, and lifetime.

ServiceDescriptorBuilder

Represents a ServiceDescriptor builder.

ServiceProvider

Represents a service provider.

Type

Represents a type.

ValidationError

Represents an validation error.

Enums

ServiceCardinality

Represents the possible cardinalities of a service dependency.

ServiceLifetime

Represents the possible service lifetimes.

Traits

Injectable

Defines the behavior of an injectable type.

Functions

exactly_one

Creates a new ServiceDependency with a cardinality of exactly one (1:1).

exactly_one_with_key

Creates a new keyed ServiceDependency with a cardinality of exactly one (1:1).

existing

Creates a new singleton ServiceDescriptor for an existing service instance.

existing_as_self

Creates a new singleton ServiceDescriptor for an existing service instance.

existing_with_key

Creates a new singleton ServiceDescriptor for an existing service instance with a key.

existing_with_key_as_self

Creates a new singleton ServiceDescriptor for an existing service instance with a key.

scoped

Initializes a new scoped ServiceDescriptorBuilder.

scoped_factory

Initializes a new scoped ServiceDescriptor.

scoped_with_key

Initializes a new scoped keyed ServiceDescriptorBuilder.

scoped_with_key_factory

Initializes a new keyed scoped ServiceDescriptor.

singleton

Initializes a new singleton ServiceDescriptorBuilder.

singleton_as_self

Initializes a new singleton ServiceDescriptorBuilder.

singleton_factory

Initializes a new singleton ServiceDescriptor.

singleton_with_key

Initializes a new keyed singleton ServiceDescriptorBuilder.

singleton_with_key_factory

Initializes a new keyed singleton ServiceDescriptor.

transient

Initializes a new transient ServiceDescriptorBuilder.

transient_as_self

Initializes a new transient ServiceDescriptorBuilder.

transient_factory

Initializes a new transient ServiceDescriptor.

transient_with_key

Initializes a new keyed transient ServiceDescriptorBuilder.

transient_with_key_as_self

Initializes a new transient keyed ServiceDescriptorBuilder.

transient_with_key_factory

Initializes a new keyed transient ServiceDescriptor.

validate

Validates the specified ServiceCollection.

zero_or_more

Creates a new ServiceDependency with a cardinality of zero or more (0:*).

zero_or_more_with_key

Creates a new keyed ServiceDependency with a cardinality of zero or more (0:*).

zero_or_one

Creates a new ServiceDependency with a cardinality of zero or one (0:1).

zero_or_one_with_key

Creates a new keyed ServiceDependency with a cardinality of zero or one (0:1).

Type Aliases

KeyedRefMut

Represents a holder for a keyed, mutable service.

Ref

Represents the type alias for a service reference.

RefMut

Represents the type alias for a mutable service reference.

ServiceFactory

Represents the callback function used to create a service.

Attribute Macros

inject

Represents the metadata used to identify an injected function.

injectable

Represents the metadata used to implement the Injectable trait.