@loopback/boot

A convention based project Bootstrapper and Booters for LoopBack Applications

Overview

A Booter is a Class that can be bound to an Application and is called to perform
a task before the Application is started. A Booter may have multiple phases to
complete its task. The task for a convention based Booter is to discover and
bind Artifacts (Controllers, Repositories, Models, etc.).

An example task of a Booter may be to discover and bind all artifacts of a given
type.

A Bootstrapper is needed to manage the Booters and execute them. This is
provided in this package. For ease of use, everything needed is packages using a
BootMixin. This Mixin will add convenience methods such as boot and booter,
as well as properties needed for Bootstrapper such as projectRoot. The Mixin
also adds the BootComponent to your Application which binds the
Bootstrapper and default Booters made available by this package.

Installation

``shell
$ npm i @loopback/boot
`

Basic Use

`ts
import {Application} from '@loopback/core';
import {BootMixin, Booter, Binding} from '@loopback/boot';
class BootApp extends BootMixin(Application) {}

const app = new BootApp();
app.projectRoot = __dirname;

await app.boot();
await app.start();
`

$3

List of Options available on BootOptions Object.

| Option | Type | Description |
| -------------- | ----------------- | ----------------------------------- |
| controllers | ArtifactOptions | ControllerBooter convention options |
| repositories | ArtifactOptions | RepositoryBooter convention options |
| datasources | ArtifactOptions | DataSourceBooter convention options |
| services | ArtifactOptions | ServiceBooter convention options |

$3

| Options | Type | Description |
| ------------ | -------------------- | ------------------------------------------------------------------------------------------------------------ |
| dirs | string \| string[] | Paths relative to projectRoot to look in for Artifact |
| extensions | string \| string[] | File extensions to match for Artifact |
| nested | boolean | Look in nested directories in dirs for Artifact |
| glob | string | A glob pattern string. This takes precedence over above 3 options (which are used to make a glob pattern). |

$3

**Experimental support. May be removed or changed in a non-compatible way in
future without warning**

To use BootExecOptions you must directly call bootstrapper.boot() and pass
in BootExecOptions. app.boot() provided by BootMixin does not take any
parameters.

`ts
const bootstrapper: Bootstrapper = await this.get(
BootBindings.BOOTSTRAPPER_KEY,
);
const execOptions: BootExecOptions = {
booters: [MyBooter1, MyBooter2],
filter: {
phases: ['configure', 'discover'],
},
};

const ctx = bootstrapper.boot(execOptions);
`

You can pass in the BootExecOptions object with the following properties:

| Property | Type | Description |
| ---------------- | ----------------------- | ------------------------------------------------ |
| booters | Constructor[] | Array of Booters to bind before running boot() |
| filter.booters | string[] | Names of Booter classes that should be run |
| filter.phases | string[] | Names of Booter phases to run |

Available Booters

$3

#### Description

Discovers and binds Controller Classes using app.controller().

#### Options

The options for this can be passed via BootOptions when calling
app.boot(options: BootOptions).

The options for this are passed in a controllers object on BootOptions.

Available options on the controllers object on BootOptions are as follows:

| Options | Type | Default | Description |
| ------------ | -------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------ |
| dirs | string \| string[] | ['controllers'] | Paths relative to projectRoot to look in for Controller artifacts |
| extensions | string \| string[] | ['.controller.js'] | File extensions to match for Controller artifacts |
| nested | boolean | true | Look in nested directories in dirs for Controller artifacts |
| glob | string | | A glob pattern string. This takes precedence over above 3 options (which are used to make a glob pattern). |

$3

#### Description

Discovers and binds Repository Classes using app.repository() (Application
must use RepositoryMixin from @loopback/repository).

#### Options

The options for this can be passed via BootOptions when calling
app.boot(options: BootOptions).

The options for this are passed in a repositories object on BootOptions.

Available options on the repositories object on BootOptions are as follows:

| Options | Type | Default | Description |
| ------------ | -------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------ |
| dirs | string \| string[] | ['repositories'] | Paths relative to projectRoot to look in for Repository artifacts |
| extensions | string \| string[] | ['.repository.js'] | File extensions to match for Repository artifacts |
| nested | boolean | true | Look in nested directories in dirs for Repository artifacts |
| glob | string | | A glob pattern string. This takes precedence over above 3 options (which are used to make a glob pattern). |

$3

#### Description

Discovers and binds DataSource Classes using app.dataSource() (Application
must use RepositoryMixin from @loopback/repository).

#### Options

The options for this can be passed via BootOptions when calling
app.boot(options: BootOptions).

The options for this are passed in a datasources object on BootOptions.

Available options on the datasources object on BootOptions are as follows:

| Options | Type | Default | Description |
| ------------ | -------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------ |
| dirs | string \| string[] | ['datasources'] | Paths relative to projectRoot to look in for DataSource artifacts |
| extensions | string \| string[] | ['.datasource.js'] | File extensions to match for DataSource artifacts |
| nested | boolean | true | Look in nested directories in dirs for DataSource artifacts |
| glob | string | | A glob pattern string. This takes precedence over above 3 options (which are used to make a glob pattern). |

$3

#### Description

Discovers and binds Service providers using app.serviceProvider() (Application
must use ServiceMixin from @loopback/service-proxy).

IMPORTANT: For a class to be recognized by ServiceBooter as a service
provider, its name must end with Provider suffix and its prototype must have a
value() method.

#### Options

The options for this can be passed via BootOptions when calling
app.boot(options: BootOptions).

The options for this are passed in a services object on BootOptions.

Available options on the services object on BootOptions are as follows:

| Options | Type | Default | Description |
| ------------ | -------------------- | ----------------- | ------------------------------------------------------------------------------------------------------------ |
| dirs | string \| string[] | ['services'] | Paths relative to projectRoot to look in for Service artifacts |
| extensions | string \| string[] | ['.service.js'] | File extensions to match for Service artifacts |
| nested | boolean | true | Look in nested directories in dirs for Service artifacts |
| glob | string | | A glob pattern string. This takes precedence over above 3 options (which are used to make a glob pattern). |

Contributions

- Guidelines
- Join the team

Tests

Run npm test` from the root folder.

Contributors

See
all contributors.

License

MIT