@fluidframework/synthesize

An Ioc type library for synthesizing a FluidObject based on FluidObject providers.

Using Fluid Framework libraries

When taking a dependency on a Fluid Framework library, we recommend using a ^ (caret) version range, such as ^1.3.4. While Fluid Framework libraries may use different ranges with interdependencies between other Fluid Framework libraries, library consumers should always prefer ^.

It allows for the creation of a DependencyContainer that can have FluidObjects registered with it based on their interface Symbol. So for example if I wanted to register something as IFoo I would need to provide and object that implements IFoo along side it.

The DependencyContainer also exposes a synthesize method that returns an object with a Promise to the correct optional and required symbols requested.

So if I wanted an object with an optional IFoo and a required IBar I would get back:

{
	IFoo: Promise<IFoo | undefined>;
	IBar: Promise<IBar>;
}

Simple Example

const dc = new DependencyContainer<FluidObject<IFoo & IBar>>();
dc.register(IFoo, new Foo());

const s = dc.synthesize({IFoo}, {});
const foo = await s.IFoo;
console.log(s.IFoo?.foo;)

API

• Providers
  • InstanceProvider
  • SingletonProvider
  • ValueProvider
  • FactoryProvider
• Synthesize
  • Optional Types
  • Required Types
  • Multiple Types
• Parent

Fluid object Providers

Fluid object Providers are the the different ways you can return a FluidObject when registering.

There are four types of providers:

1. Value Provider
2. Async Value Provider
3. Factory Provider
4. Async Factory Provider

type FluidObjectProvider<T> =
	| NonNullable<T>
	| Promise<NonNullable<T>>
	| ((dependencyContainer: IFluidDependencySynthesizer) => NonNullable<T>)
	| ((dependencyContainer: IFluidDependencySynthesizer) => Promise<NonNullable<T>>);

Value Provider

Provide an FluidObject of a given type.

Usage

const dc = new DependencyContainer<FluidObject<IFoo>>();

dc.register(IFoo, new Foo());

Async Value Provider

Provide a Promise to an FluidObject of a given type.

Usage

const dc = new DependencyContainer<FluidObject<IFoo>>();

const generateFoo: Promise<IFoo> = await() => {
    const foo = new Foo();
    await foo.initialize();
    return foo;
}

dc.register(IFoo, generateFoo());

Factory Provider

Provide a function that will resolve an FluidObject of a given type.

Usage

const dc = new DependencyContainer<FluidObject<IFoo & IBar>>();
const fooFactory = () => new Foo();
dc.register(IFoo, fooFactory);

// Factories can utilize the DependencyContainer if the FluidObject depends
// on other providers
const barFactory = (dc) => new Bar(dc);
dc.register(IFoo, barFactory);

Async Factory Provider

Provide a function that will resolve a Promise to an FluidObject of a given type.

Usage

const dc = new DependencyContainer<FluidObject<IFoo & IBar>>();

const generateFoo: Promise<IFoo> = await() => {
    const foo = new Foo();
    await foo.initialize();
    return foo;
}

dc.register(IFoo, generateFoo);

const generateBar: Promise<IBar> = await(dc) => {
    const bar = new Bar();
    await bar.initialize(dc);
    return bar;
}

dc.register(IBar, generateBar);

Synthesize

Once you have a DependencyContainer with registered providers you can synthesize/generate a new FluidObject from it. The object that is returned will have the correct typing of optional and required types.

An Example:

If I wanted an object with an optional IFoo and a required IBar I would get back:

{
	IFoo: Promise<IFoo | undefined>;
	IBar: Promise<IBar>;
}

synthesize takes optionalTypes and requiredTypes as well as their corresponding types. FluidObjectSymbolProvider<> is a TypeScript type that ensures the types being passed match the ones in the object being provided.

Optional Types

Optional types will return a Promise to it's corresponding FluidObject or undefined. Because of this we need to do an if check to validate the object or use the ? like in the example below.

const dc = new DependencyContainer<FluidObject<IFoo>>();

const s = dc.synthesize<IFoo>({ IFoo }, {});
const foo = await s.IFoo;
console.log(foo?.foo);

Note: Because of how generics in TypeScript work we need to provide an empty requiredTypes object even though we don't need to provide the type.

Required Types

Required types will return a Promise to it's corresponding FluidObject or it will throw.

You can see below that we don't need to add the ? to check our requested type.

const dc = new DependencyContainer<FluidObject<IFoo>>();

const scope = dc.synthesize<{}, IFoo>({}, { IFoo });
const foo = await s.IFoo;
console.log(foo.foo);

Multiple Types

You can declare multiple types for both Optional and Required using the & or creating a separate type.

const dc = new DependencyContainer<FluidObject<IFoo & IBar>>();

const scope = dc.synthesize<IFoo & IBar>({ IFoo, IBar }, {});
const fooP = s.IFoo;
const barP = s.IBar;
const [foo, bar] = Promise.all([foo, bar]);
console.log(foo?.foo);
console.log(bar?.bar);

const dc = new DependencyContainer<FluidObject<IFoo & IBar>>();

const scope = dc.synthesize<{}, IFoo & IBar>({}, { IFoo, IBar });
const fooP = s.IFoo;
const barP = s.IBar;
const [foo, bar] = Promise.all([foo, bar]);
console.log(foo.foo);
console.log(bar.bar);

const dc = new DependencyContainer<FluidObject<IFoo & IBar>>();

const scope = dc.synthesize<IFoo, IBar>({ IFoo }, { IBar });
const fooP = s.IFoo;
const barP = s.IBar;
const [foo, bar] = Promise.all([foo, bar]);
console.log(foo?.foo);
console.log(bar.bar);

Parent

The DependencyContainer takes one optional parameter which is the parent. When resolving providers the DependencyContainer will first check the current container then look in the parent.

Trademark

This project may contain Microsoft trademarks or logos for Microsoft projects, products, or services.

Use of these trademarks or logos must follow Microsoft's Trademark & Brand Guidelines.

Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.