@hogbros/observe-property v0.2.0

observeProperty

Wire in to property changes on an object

Installation

npm install @hogbros/observe-property --save

Basic Usage

import { observeProperty } from "@hogbros/observe-property";

const myObject = {
  myObservedProperty: "foo";
};
observeProperty(
  myObject,
  "myObservedProperty",
  (target, oldValue, newValue) => console.log(
    `myObservedProperty changed from ${oldValue} to ${value}`
  )
);
myObject.myObservedProperty = "bar";
// console: myObservedProperty changed from foo to bar

Experimental Decorators

import { onSet } from "@hogbros/observe-property";

class MyClass {
  @onSet((target, oldValue, newValue) =>
    console.log(`myObservedProperty changed from ${oldValue} to ${value}`)
  )
  myObservedProperty?: string;
}

let myObject = new MyClass();
myObject.myObservedProperty = "foo";
// console: myObservedProperty changed from undefined to foo
myObject.myObservedProperty = "bar";
// console: myObservedProperty changed from foo to bar

How it Works

observeProperty will dynamically create a property getter/setter on the specified object. The setter on this property will invoke a callback method to notify of any updates on the property.