gskachkov

const metaHandler = { 
  get: function (dt, trapName) { 
    console.log(dt, trapName);
    return Reflect[trapName]; 
  } 
};

const dummyTarget = {};
const baseHandler = new Proxy(dummyTarget, metaHandler);
const target = {};

gskachkov

var target = { id : "boo" };
var p = new Proxy(target, {
  get: function(target, property, receiver) {
  },
  set: function(target, property, value, receiver) {
  },
  defineProperty: function(target, property, propDesc) {
  },
  deleteProperty: function(target, property) {
  },

gskachkov

const proxy = new Proxy(
  { id: "id-0" }, 
  {
    set: function (target, property, value, receiver) {
      if (property.charAt(0) === "_") return false;
      target[property] = value;
      return true;
    }
  ...
  }

gskachkov

var target = { id: "id-0" };
var handler = { 
  set: function (target, property, value, receiver) {
    if (property.charAt(0) === "_") return false;
    target[property] = value;
    return true;
  }
};

var proxy = new Proxy(target, handler);

gskachkov

const foo = (a, b, c) => `${a}:${b}:${c}`;

const proxy = new Proxy(foo, {
  apply: function(target, thisArg, argumentsList) {
    return target.apply(thisArg, argumentsList);
  }
});

console.log(proxy("1", "2", "3")); // 1:2:3

gskachkov

class A {  
  constructor (value) { this.value = value; }
  getValue() { return this.value; } 
}

const proxiedClass = new Proxy(A, {
  construct: function(target, [ first ], newTarget) {
     return new target(first + ":proxy-value");
  }
});

gskachkov

const handler = {
  get: function(target, property, receiver) {
    if (property.startAt(0) === "_") return undefined; 
    return target[property];
  }
};

const proxy = new Proxy({}, handler);

console.log(proxy.id); // 'ABCD'

gskachkov

const handler = {
  defineProperty: function(target, property, descriptor) {
    if (property.charAt(0) === "_") return false; 
    return Reflect.defineProperty(target, property, descriptor);
  }
};

const proxy = new Proxy({}, handler);

proxy.id = "ABCD"; // { id: 'ABCD' } 

gskachkov

var proxiedObject = new Proxy(target, handler);

gskachkov

var weaver =  function (target, methodName) {
  var before = function () { 
    console.log(arguments);
  };
  
  var old = target[methodName];
  target[methodName] = function () {
    before.apply(this, arguments);
    return old.apply(this, arguments);
  };