cls-class-proxy

A Proxy-based lightweight library to add Continuation-Local Storage aka (CLS) to class contructor, method calls, getters and setters.

• Installation
• Quick start
  • Decorator-based
  • Non-decorator based
• Options

Installation

1. Install libraries

   npm i cls-class-proxy cls-hooked

2. Install typings if you use typescript

   npm i -D @types/cls-hooked

Quick start

Decorator-based

1. Set in your tsconfig.json

   "experimentalDecorators": true,
   "emitDecoratorMetadata": true

2. In your code

   import { getNamespace } from 'cls-hooked'
   import { proxify, CLS_CLASS_PROXY_NAMESPACE_NAME } from 'cls-class-proxy'
   @proxify()
   class Example {
     constructor() {
       const namespace = getNamespace(CLS_CLASS_PROXY_NAMESPACE_NAME)
       // At this point the namespace has an active contex (namspace.active returns the context)
       // You can set and get data for the context
     }
     method1() {
       const namespace = getNamespace(CLS_CLASS_PROXY_NAMESPACE_NAME)
       // At this point the namespace has an active contex (namspace.active returns the context)
       // You can set and get data for the context
     }
     get prop1() {
       const namespace = getNamespace(CLS_CLASS_PROXY_NAMESPACE_NAME)
       // At this point the namespace has an active contex (namspace.active returns the context)
       // You can set and get data for the context
     }
     set prop2() {
       const namespace = getNamespace(CLS_CLASS_PROXY_NAMESPACE_NAME)
       // At this point the namespace has an active contex (namspace.active returns the context)
       // You can set and get data for the context
     }
   }

Non-decorator based

import { getNamespace } from 'cls-hooked'
import { proxify, CLS_CLASS_PROXY_NAMESPACE_NAME } from 'cls-class-proxy'
class Example {}
const ExampleProxified = proxify()(Example)

Options

proxify accepts an optional object with options:

• namespace: string - custom namespace name to use instead of default CLS_CLASS_PROXY_NAMESPACE_NAME
• cache: boolean - to wrap method, getter and setter calls in a CLS context cls-class-proxy recursively looks up
  property descriptors on a target object and its prototype chain. To avoid doing that for every call cls-class-proxy caches property descriptors in a Map. It’s enabled by default.