@rbxts/jsnatives

Proxy - get hook

The get hook is triggered when a property is accessed on the proxy.

Signature

function get<T>(target: T, key: unknown, proxy: T): any;

Description

The get handler trap is called when a property is read from the proxy object. It allows you to intercept and customize property access operations.

Note: If raw is provided and contains the key, get hook will be bypassed.

Parameters

target: The original target object the proxy is wrapping
key: The property key (string, number, or symbol) being accessed
proxy: The proxy instance itself

Return value

The value that should be returned for the property access

Examples

Basic property access interception

const target = { message: "Hello" };
const proxy = new Proxy(target, {
  get: (target, prop, proxy) => {
    console.log(`Accessing property: ${String(prop)}`);
    return target[prop];
  }
});

console.log(proxy.message); // Logs: "Accessing property: message", then "Hello"
console.log(proxy["message"]); // Logs: "Accessing property: message", then "Hello"

Virtual properties

const target = { x: 10, y: 20 };
const proxy = new Proxy(target, {
  get: (target, prop, proxy) => {
    if (prop === "sum") {
      return target.x + target.y;
    }
    return target[prop];
  }
});

console.log(proxy.sum); // 30 (virtual property)

Using raw properties to bypass the get trap

const target = {};
const proxy = new Proxy(target, {
  get: (target, prop, proxy) => {
    console.log(`Get trap for ${String(prop)}`);
    return `Trapped: ${String(prop)}`;
  }
}, {
  directProp: "Direct access"
});

console.log(proxy.normalProp); // Logs: "Get trap for normalProp", then "Trapped: normalProp"
console.log(proxy.directProp); // Logs: "Direct access" (bypasses the get trap)

Conditional access control

const userData = { username: "admin", role: "admin", email: "admin@example.com" };
const protectedData = new Proxy(userData, {
  get: (target, prop, proxy) => {
    if (prop === "email" && target.role !== "admin") {
      return "Permission denied";
    }
    return target[prop];
  }
});

console.log(protectedData.username); // "admin"
console.log(protectedData.email); // "admin@example.com" (allowed because role is admin)

// Change role
userData.role = "user";
console.log(protectedData.email); // "Permission denied"