Buildpack/BuildBus
- ~TargetProvider ⇐ Trackable
  - new TargetProvider(bus, dep, getExternalTargets)
  - instance
    - .name : string
    - .own : Object.<string, Target>
    - .phase : string
    - .declare(declarations)
    - .of(depName) ⇒ Object.<string, Target>
  - inner
    - ~toJSON()
- ~getExternalTargets ⇒ TargetProvider

Handles interactions between a BuildBus and an "extension" package participating in the BuildBus declare/intercept lifecycle.

The targets object used by declare and intercept functions is a TargetProvider. Each extension receives its own TargetProvider, which provides methods for declaring its own targets, intercepting its own targets, and intercepting the targets of other extensions.

Extends: Trackable

~TargetProvider ⇐ Trackable
- new TargetProvider(bus, dep, getExternalTargets)
- instance
  - .name : string
  - .own : Object.<string, Target>
  - .phase : string
  - .declare(declarations)
  - .of(depName) ⇒ Object.<string, Target>
- inner
  - ~toJSON()

Creates an instance of TargetProvider.

Parameters

Name

Type

Description

bus

BuildBus | function

BuildBus using this TargetProvider, or, when testing, a logging function.

dep

Object

The package which owns this TargetProvider.

dep.name

string

Name of the package which owns this.

getExternalTargets

getExternalTargets

Function this TargetProvider will use to retrieve external packages when they are requested with .of(). Should usually be a delegate to BuildBus's getExternalTargets()

The targets this package has declared in the declare phase.

The phase currently being executed. Either declare or intercept.

Call this function in the declare phase to register targets that this package and other packages can intercept.

Parameters

Name

Type

Description

declarations

Object.<string, Target>

An object whose keys are the names of targets to declare, and whose properties are newly constructed Targets.

Call this function in the intercept phase to get the targets of other packages, which can then be intercepted by calling .tap() methods on them.

Returns: Object.<string, Target> — - An object whose keys are the names of the requested package's targets, and whose values are the target objects.

Parameters

Name

Type

Description

depName

string

The package whose targets you want to retrieve.

Respond to a request from a TargetProvider to retrieve a different(external) TargetProvider.

This callback pattern helps to loosely couple TargetProviders so they are more testable.

Returns: TargetProvider — TargetProvider for the requested targets.

Parameters

Name

Type

Description

requestor

TargetProvider

TargetProvider making the request.

requested

string

External targets being requested.

Source Code: pwa-studio/packages/pwa-buildpack/lib/BuildBus/TargetProvider.js