Rename articles prefixed with js-

snippets/js/s/proxy-introduction.md

@@ -0,0 +1,55 @@
+---
+title: An Introduction to JavaScript Proxy
+shortTitle: JavaScript Proxy Introduction
+type: story
+language: javascript
+tags: [object,proxy,pattern]
+author: chalarangelo
+cover: red-mountain-range
+excerpt: A quick introduction to the JavaScript Proxy object and where it can be used.
+dateModified: 2023-04-02T05:00:00-04:00
+---
+
+The JavaScript `Proxy` object is a relatively new addition to the language, having been introduced in ES6. It's based on the **software design pattern** of the same name, which creates a wrapper for another object, **intercepting** and **redefining** fundamental operations for that object.
+
+A `Proxy` object is defined as follows:
+
+```js
+const proxy = new Proxy(target, handler);
+```
+
+The `target` is the object that the proxy wraps around, while the `handler` is an object that contains one or more **"traps"** - functions that intercept operations performed on the target object.
+
+There are a variety of available traps that can be used to customize the behavior of the target object. Here's a brief overview of all available traps and what each one does:
+
+- `get(target, prop, receiver)` - Intercepts calls to `target[prop]`.
+- `set(target, prop, value, receiver)` - Intercepts calls to `target[prop] = value`.
+- `has(target, prop)` - Intercepts calls to `prop in target`.
+- `apply(target, thisArg, argumentsList)` - Intercepts calls to functions.
+- `construct(target, argumentsList, newTarget)` - Intercepts calls to the `new` operator.
+- `defineProperty(target, prop, descriptor)` - Intercepts calls to `Object.defineProperty()`.
+- `deleteProperty(target, prop)` - Intercepts calls to `delete target[prop]`.
+- `getOwnPropertyDescriptor(target, prop)` - Intercepts calls to `Object.getOwnPropertyDescriptor()`.
+- `ownKeys(target)` - Intercepts calls to `Object.getOwnPropertyNames()` and `Object.getOwnPropertySymbols()`.
+- `getPrototypeOf(target)` - Intercepts calls to `Object.getPrototypeOf()`.
+- `setPrototypeOf(target, prototype)` - Intercepts calls to `Object.setPrototypeOf()`.
+- `isExtensible(target)` - Intercepts calls to `Object.isExtensible()`.
+- `preventExtensions(target)` - Intercepts calls to `Object.preventExtensions()`.
+
+There are many common and novel use-cases for the `Proxy` object, utilizing one or more of these traps. Here's a simple example that intercepts a `get` call and returns `null` if the property doesn't exist in the target object:
+
+```js
+const targetObj = { name: 'John', age: 30 };
+
+const handler = {
+  get(target, property) {
+    return property in target ? target[property] : null;
+  }
+};
+
+const proxyObj = new Proxy(targetObj, handler);
+
+proxyObj.name; // 'John'
+proxyObj.age; // 30
+proxyObj.address; // null
+```