Shulou(Shulou.com)06/02 Report--

This article mainly explains "how to use Proxy to proxy classes in Js", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let Xiaobian take you to learn "how to use Proxy to proxy classes in JS"!

How to use Proxy

As the MDN simply and dryly defines:

Proxy objects are used to define custom behavior for basic operations (such as attribute lookup, assignment, enumeration, function call, etc.).

While this is a nice summary, I don't really understand what Proxy can do or what it can help us achieve.

First of all, the concept of Proxy comes from metaprogramming. Metaprogramming is simply code that allows us to run the application (or core) code we write. For example, the infamous eval function, which allows us to execute string code as executable code, belongs in the metaprogramming realm.

The ProxyAPI allows us to create intermediate layers between an object and its consumer entities, and this feature gives us the ability to control the object, such as deciding how to get and set it, and even customizing what we can do when accessing properties that do not exist on the object.

How to use proxy API

varp=newProxy(target,handler);

The Proxy constructor takes a target object and a handler object that intercepts different behaviors of the target object. You can set the following interceptors:

has-intercepts in operation. For example, you can use it to hide certain properties on objects.

get-Used to intercept read operations. For example, you can use it to return default values when trying to read properties that don't exist.

set-Used to intercept assignment operations. For example, you can add validation logic when assigning attributes, and throw errors if validation fails.

apply-Used to intercept function call operations. For example, you can wrap all function calls in a try/catch block.

These are just a few of the interceptions; you can find the full list on MDN.

At this point, I believe that we have a deeper understanding of "how to use Proxy to proxy classes in Js," may wish to actually operate it! Here is the website, more related content can enter the relevant channels for inquiry, pay attention to us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.