Prop-proxy NPM

Prop-Proxy

Proxy for class properties

Prop-Proxy allows you to intercept getters and setters of class attributes through decorators

Installation

This package need to be used with Typescript

npm install prop-proxy --save
yarn add prop-proxy

Configuration

You need to enable in tsconfig.json:

{
  "compilerOptions": {
    {
        "experimentalDecorators": true, 
        "emitDecoratorMetadata": true
    }
}

Usage

Using proxy for interception

import { usePropertyProxy } from 'prop-proxy'

interface Struct {
    title: string;
    isActive: boolean;
}

const { Property, proxy } = usePropertyProxy<Struct>();

class Category implements Struct {
    @Property()
    title!: string;

    @Property()
    isActive!: boolean;

    constructor({title, isActive}: Struct){
        Object.assign(this, {title, isActive})
    }
}

//getter intercept
proxy.getTitle((value) => `other_${value}`)

//setter intercept
proxy.setIsActive(({setValue, value}) => setValue(true));

const category = new Category({title: 'title', isActive: false})

console.log(category.title) // output: other_title

console.log(category.isActive) // output: true

Using validator with class-validator

import { usePropertyProxy } from 'prop-proxy'
import { Length } from 'class-validator'

interface Struct {
    title: string;
    isActive: boolean;
}

const { Property, Validate } = usePropertyProxy<Struct>();

@Validate()
class Category implements Struct {
    @Property()
    @Length(0, 10)
    title!: string;

    @Property()
    isActive!: boolean;

    constructor({title, isActive}: Struct){
        Object.assign(this, {title, isActive})
    }
}

const category = new Category({title: 'title longer than 10 characters', isActive: true})

// output: an error is thrown, as the title length cannot be greater than 10 characters, according to schema.

The error is thrown both for values sent by the constructor and for those modified by the Class instance.

Using validator with zod

import { usePropertyProxy } from 'prop-proxy'
import { z } from 'zod'

interface Struct {
    title: string;
    isActive: boolean;
}

const SchemaCategory: z.ZodType<Struct> = z.object({
    title: z.string().max(10),
    isActive: z.boolean(),
})

const { Property, Validate } = usePropertyProxy<Struct>();

@Validate(SchemaCategory)
class Category implements Struct {
    @Property()
    title!: string;

    @Property()
    isActive!: boolean;

    constructor({title, isActive}: Struct){
        Object.assign(this, {title, isActive})
    }
}

const category = new Category({title: 'title longer than 10 characters', isActive: true})

// output: an error is thrown, as the title length cannot be greater than 10 characters, according to schema.

The error is thrown both for values sent by the constructor and for those modified by the Class instance.

Using validator with yup

import { usePropertyProxy } from 'prop-proxy'

import { object, string, boolean } from 'yup';

interface Struct {
    title: string;
    isActive: boolean;
}

const SchemaCategory = object({
  title: string().required().max(10),
  isActive: boolean().required(),
});

const { Property, Validate } = usePropertyProxy<Struct>();

@Validate(SchemaCategory)
class Category implements Struct {
    @Property()
    title!: string;

    @Property()
    isActive!: boolean;

    constructor({title, isActive}: Struct){
        Object.assign(this, {title, isActive})
    }
}

const category = new Category({title: 'title longer than 10 characters', isActive: true})

// output: an error is thrown, as the title length cannot be greater than 10 characters, according to schema.