ditox-react package

Dependency injection helpers for React.js

Please see the documentation at ditox.js.org

Installation

You can use the following command to install this package:

npm install --save ditox-react

Packages can be used as UMD modules. Use jsdelivr.com CDN to load ditox and ditox-react:

<script src="//cdn.jsdelivr.net/npm/ditox/dist/umd/index.js"></script>
<script src="//cdn.jsdelivr.net/npm/ditox-react/dist/umd/index.js"></script>
<script>
  const container = Ditox.createContainer();
  // DitoxReact.useDependency(SOME_TOKEN);
</script>

Overview

ditox-react is a set of helpers for providing and using a dependency container in React apps:

• Components:
  • DependencyContainer — creates and provides a new container to React children. Optionally binds dependencies via a binder callback. Can start a new root container with root flag.
  • DependencyModule — binds a dependency module to a new container (supports scope: singleton (default) or scoped).
  • CustomDependencyContainer — provides an existing dependency container.
• Hooks:
  • useDependencyContainer(mode?) — returns a provided dependency container. With mode = 'strict' it throws if the container is not provided; by default it returns undefined when not provided.
  • useDependency(token) — resolves and returns a value by a specified token. Throws if a container or the value is not found.
  • useOptionalDependency(token) — returns a resolved value by a specified token, or undefined if not found or not provided.

Usage Examples

import {token} from 'ditox';
import {
  DependencyContainer,
  useDependency,
  useDependencyContainer,
  useOptionalDependency,
} from 'ditox-react';

const FOO_TOKEN = token<string>();
const BAR_TOKEN = token<string>();

function appDependencyBinder(container) {
  container.bindValue(FOO_TOKEN, 'foo');
}

function App() {
  return (
    <DependencyContainer root binder={appDependencyBinder}>
      <NestedComponent />
    </DependencyContainer>
  );
}

function NestedComponent() {
  // Get access to the container (optionally)
  const container = useDependencyContainer(); // or useDependencyContainer('strict') to enforce presence

  // Use a resolved value
  const foo = useDependency(FOO_TOKEN);

  // Use an optional value. It is not provided in this example.
  const bar = useOptionalDependency(BAR_TOKEN);

  useEffect(() => {
    console.log({foo, bar}); // {foo: 'foo', bar: undefined}
  }, [foo, bar]);

  return null;
}

Providing an existing container

import {createContainer, token} from 'ditox';
import {CustomDependencyContainer, useDependency} from 'ditox-react';

const GREETING_TOKEN = token<string>();

const container = createContainer();
container.bindValue(GREETING_TOKEN, 'Hello');

function App() {
  return (
    <CustomDependencyContainer container={container}>
      <Greeting />
    </CustomDependencyContainer>
  );
}

function Greeting() {
  const text = useDependency(GREETING_TOKEN);
  return <>{text}</>;
}

Dependency Modules

Dependency modules can be provided to the app with the <DependencyModule /> component. You can also specify a binding scope (singleton by default or scoped):

function App() {
  return (
    <DependencyModule module={LOGGER_MODULE} scope="singleton">
      <NestedComponent />
    </DependencyModule>
  );
}

API Reference

• Components

  • DependencyContainer(props)
    • props.children: ReactNode — React children to wrap
    • props.root?: boolean — if true, create a new root container that does not inherit from any parent container
    • props.binder?: (container: Container) => unknown — optional callback to set up bindings for the newly created container
    • Behavior: creates a new container linked to the parent container by default; removes all bindings on unmount
  • CustomDependencyContainer(props)
    • props.children: ReactNode — React children to wrap
    • props.container: Container — an existing container instance to provide
  • DependencyModule(props)
    • props.children: ReactNode — React children to wrap
    • props.module: ModuleDeclaration — module to bind to a new container
    • props.scope?: 'singleton' | 'scoped' — scope for the module bindings (default: 'singleton')

• Hooks

  • useDependencyContainer(mode?: 'optional' | 'strict')
    • Returns the container. In 'strict' mode throws if not provided; in optional mode returns undefined if not provided
  • useDependency(token: Token): T
    • Resolves and returns the value; throws if not bound or container is missing
  • useOptionalDependency(token: Token): T | undefined
    • Returns the value if bound, otherwise undefined

Notes:

• A parent container (if provided higher in the tree) is used as the parent for new containers created by DependencyContainer and DependencyModule, unless root is set to true.
• All bindings made inside a DependencyContainer are removed on unmount.

This project is licensed under the MIT license.