API docs: metadata.decoratorfactory | LoopBack Documentation

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DecoratorFactory class

Base factory class for decorator functions

Signature:

export declare class DecoratorFactory<T, // Type of the metadata spec for individual class/method/property/parameter
M extends T | MetadataMap<T> | MetadataMap<T[]>, // Type of the metadata
D extends DecoratorType> 

Example

function classDecorator(spec: MySpec): ClassDecorator {
  return ClassDecoratorFactory.createDecorator('my-key', spec);
}

function classDecorator(spec: MySpec): ClassDecorator {
  const factory: ClassDecoratorFactory<MySpec>('my-key', spec);
  return factory.create();
}

These functions above declare @classDecorator that can be used as follows:

@classDecorator({x: 1})
class MyController {}

Constructors

Constructor	Modifiers	Description
(constructor)(key, spec, options)		Construct a new class decorator factory

Properties

Property	Modifiers	Type	Description
decoratorName	`protected`	string
key	`protected`	string
options	`protected`	DecoratorOptions
spec	`protected`	T
TARGET	`static`	string	A constant to reference the target of a decoration

Methods

Method	Modifiers	Description
_createDecorator(key, spec, options)	`protected` `static`	Create a decorator function
allowInheritance()	`protected`
cloneDeep(val)	`static`
create()		Create a decorator function of the given type. Each sub class MUST implement this method.
decorate(target, member, descriptorOrIndex)	`protected`	Base implementation of the decorator function
duplicateDecorationError(target, member, descriptorOrIndex)	`protected`	Create an error to report if the decorator is applied to the target more than once
getNumberOfParameters(target, member)	`static`	Get the number of parameters for a given constructor or method
getTarget(spec)		Get the optional decoration target of a given spec
getTargetName(target, member, descriptorOrIndex)	`static`	Get the qualified name of a decoration target.
inherit(inheritedMetadata)	`protected`	Inherit metadata from base classes. By default, this method merges base metadata into the spec if `allowInheritance` is set to `true`. To customize the behavior, this method can be overridden by sub classes.
mergeWithInherited(inheritedMetadata, target, member, descriptorOrIndex)	`protected`	This method is called by the default implementation of the decorator function to merge the spec argument from the decoration with the inherited metadata for a class, all properties, all methods, or all method parameters that are decorated by this decorator. It MUST be overridden by subclasses to process inherited metadata.
mergeWithOwn(ownMetadata, target, member, descriptorOrIndex)	`protected`	This method is called by the default implementation of the decorator function to merge the spec argument from the decoration with the own metadata for a class, all properties, all methods, or all method parameters that are decorated by this decorator. It MUST be overridden by subclasses to process own metadata.
withTarget(spec, target)		Set a reference to the target class or prototype for a given spec if it’s an object