vue stops the executing function

With the development of front-end technology, we put more and more business logic on the front-end processing. In this process, many times we need to perform some asynchronous operations on the page, such as obtaining data through AJAX requests or performing some time-consuming calculations. However, in some cases, we may want to stop the asynchronous operation being executed. How to achieve this? This article explains how to use Vue to stop an executing function.

First, we need to understand some basic concepts of asynchronous operations in Vue. In Vue, asynchronous operations are generally divided into two types: Promise and timer. The following describes how to stop the executing function in these two cases.

Stop the executing Promise

Promise is a JavaScript asynchronous programming solution. Its main function is to solve the problem of callback hell. In Vue, we often use Promise to handle asynchronous operations. So how to stop the executing Promise?

First of all, we need to clarify that there are three states in Promise: Pending (in progress), Resolved (completed) and Rejected (failed). When a Promise is in the Pending state, we can cancel the execution of the Promise object by calling the .cancel() method of the Promise object. For specific implementation, please refer to the following code:

// 定义一个 Promise 对象
const promise = new Promise((resolve, reject) => {
  setTimeout(() => {
    console.log("Promise 执行完毕");
    resolve();
  }, 5000)
});

// 取消 Promise 的执行
promise.cancel = function(){
  console.log("Promise 被取消了");
};

// 执行 Promise
promise.then(() => {
  console.log("Promise 执行成功");
}).catch(() => {
  console.error("Promise 执行失败");
});

// 取消 Promise
promise.cancel();  // 控制台输出 "Promise 被取消了"

In the above code, we define a Promise object and set a timer that will be executed after 5 seconds. We also define a .cancel() method to stop the execution of the Promise object. Before executing the Promise object, we called the .cancel() method to stop the execution of the Promise object, and the console output "Promise was canceled". We can see that after the Promise object is canceled, its status changes to Pending and will no longer be executed.

Stop the executing timer

Timer is also a situation we often encounter in Vue development. Sometimes we need to perform some time-related operations on the page, such as countdown. In some cases, we may need to stop the executing timer.

So how to stop the executing timer? We can use the clearTimeout() method to stop the execution of the timer. For specific implementation, please refer to the following code:

// 定义一个定时器
const timer = setInterval(() => {
  console.log('timer 正在进行中');
}, 1000)

// 取消定时器的执行
timer.cancel = function(){
  console.log("timer 已被取消");
  clearInterval(timer);
};

// 停止定时器的执行
timer.cancel();  // 控制台输出 "timer 已被取消"

In the above code, we define a timer that will be executed after an interval of 1 second. We also define a .cancel() method to stop the execution of the timer. Before executing the timer, we called the .cancel() method to stop the execution of the timer, and the console output "timer has been cancelled". After the timer is canceled, it will not continue to execute.

Conclusion

In Vue development, asynchronous operations are very common. In order to achieve a better user experience, we may need to stop the asynchronous operation being executed at some point. This article explains how to use Vue to stop an executing function. Through the introduction of this article, we can see that whether it is a Promise or a timer, we can stop an asynchronous operation by canceling its execution. We can use the cancel() method to stop the executing Promise or timer to achieve our purpose.

In short, stopping the executing function is a very important part of asynchronous programming and must be mastered for Vue development. I hope the introduction in this article can help you better handle asynchronous operations and improve development efficiency and user experience.

The above is the detailed content of vue stops the executing function. For more information, please follow other related articles on the PHP Chinese website!