Performed on the browser stage: How the front-end challenges the limits of page refresh

Preface
Basics: The wonderful use of location.reload()
Advanced article: Refresh-free experience brought by Ajax
Framework: Partial refresh of Vue and React
Practice: Creative application of dynamic page refresh

Preface

In the endless digital ocean, an invisible bridge is established between the user and the browser, connecting the reality and virtuality of the web page. On this bridge, JavaScript is like a magician, which can use various ingenious techniques to give the page a completely new look and display a gorgeous scene.

This blog will take you into the wonderful world of front-end and reveal the behind-the-scenes secrets of page refresh. From simple methods to advanced technical means, we will explore how to put on a show on the browser stage that will dazzle users.

Basics: The wonderful use of location.reload()

location.reload() is a method in JavaScript used to reload the current page. It has some wonderful uses, but it needs to be used with caution because page refreshes may affect the user experience. The following is a basic introduction to location.reload() as well as some related advantages, disadvantages and applicable scenarios.

basic introduction:

location.reload()Method is used to refresh the current page, it reloads the page and retains the state of the current page. This means that the form the user is filling in, the scroll position, etc. will be retained. This method can be called directly or used in an event handler, such as a button click event.

// 直接调用
location.reload();

// 在事件处理程序中使用
document.getElementById('refreshButton').addEventListener('click', function() {
    
    
  location.reload();
});

Advantages and Disadvantages:

advantage:

Simple and easy to use: location.reload() is a very simple method to refresh the page, suitable for rapid page update needs.
Preserved state: After the page is refreshed, the user's current state (such as form data, scroll position) will be retained and will not be lost.

shortcoming:

User experience: Forced refresh of the page may interrupt the user's operation and affect the user experience. In some cases, it is better to use a more fine-grained refresh strategy, such as a partial refresh rather than a full page refresh.
Performance overhead: Full page refresh will reload all resources, including unnecessary resources, resulting in performance overhead. In scenarios that require frequent refreshes, web page loading speed may be affected.

Applicable scene:

Simple page update: You can use location.reload() when the page only needs simple updates without involving complex logic.
Development and debugging: During the development process, if you need to force refresh the page to view the latest code changes, you can use this method.
Pages with infrequent user interaction: Consider using location.reload()

In general, location.reload() is a simple and effective page refresh method, but it needs to be used with caution, especially when forcing a refresh of the entire page may affect the user experience. . In some scenarios, consider using more fine-grained refresh strategies, such as partial refresh, to improve performance and user experience.

Advanced article: Refresh-free experience brought by Ajax

Advanced article: Refresh-free experience brought by Ajax

Ajax (Asynchronous JavaScript and XML) is a technology for creating fast, dynamic web pages that allows data exchange with the server through asynchronous requests without reloading the entire page. By using Ajax, partial refresh can be achieved to improve user experience.

Basic usage of Ajax:

Create an XMLHttpRequest object:
```
var xhr = new XMLHttpRequest();
```

Configure request parameters:

xhr.open('GET', 'example.com/api/data', true);

Define callback function:

xhr.onreadystatechange = function() {
      
      
  if (xhr.readyState == 4 && xhr.status == 200) {
      
      
    // 处理响应数据
    var responseData = JSON.parse(xhr.responseText);
    // 执行更新页面的操作
    updatePage(responseData);
  }
};

send request:
```
xhr.send();
```

How to use Ajax to improve user experience:

Partial refresh: Use Ajax to update only part of the page, rather than the entire page. This reduces bandwidth consumption and increases page loading speed.
Asynchronous loading: Will delay loading of parts that do not affect the main content of the page, such as pictures, advertisements, etc. This allows the main content to load faster and improves page responsiveness.
Real-time update: Ajax can be used to update page content in real time, such as chat messages, news updates, etc., without the need for users to manually refresh the page.
Error handling and loading prompts: When using Ajax, handle errors in a timely manner and provide users with friendly error prompts. At the same time, during the data loading process, a loading prompt is displayed to let the user know that the page is undergoing some operation.
Front-end routing: Use front-end routing technology to load different page content through Ajax to implement a single page application (SPA) and improve user experience.
Cache management: Make reasonable use of cache to avoid repeated requests for the same data. Update data when needed by setting a cache expiration time or manually refreshing the cache.
Graceful downgrade: Considering the user equipment and network environment, provide some graceful downgrade strategies to ensure that users can still obtain basic services when support is not supported or the network is poor. Features and information.

example:

// 使用 jQuery 的 Ajax
$.ajax({
    
    
  url: 'example.com/api/data',
  method: 'GET',
  success: function(responseData) {
    
    
    // 更新页面
    updatePage(responseData);
  },
  error: function(xhr, status, error) {
    
    
    // 处理错误
    console.error('Ajax request failed: ' + error);
  }
});

By using Ajax, we can achieve a smoother user experience, reduce page load times, and provide the ability to update in real time as the user interacts with the page. However, during implementation, attention needs to be paid to handling errors, properly utilizing cache, and paying attention to all aspects of the user experience.

Framework: Partial refresh of Vue and React

Vue.js and React.js are two popular front-end frameworks. They both provide convenient tools and mechanisms to implement partial refresh to improve the user experience. The following takes Vue and React as examples to demonstrate how to achieve partial refresh through these two frameworks, emphasizing the convenience and performance advantages brought by the framework.

Vue.js:

Vue.js is a progressive JavaScript framework that is easy to learn and integrate. It achieves efficient local refresh through data binding and componentization.

Example:

<!-- HTML 模板 -->
<div id="app">
  <p>{
   
   { message }}</p>
  <button @click="updateMessage">Update Message</button>
</div>

<!-- JavaScript 代码 -->
<script src="https://cdn.jsdelivr.net/npm/vue@2"></script>
<script>
  new Vue({
      
      
    el: '#app',
    data: {
      
      
      message: 'Hello, Vue!'
    },
    methods: {
      
      
      updateMessage: function() {
      
      
        // 模拟异步更新数据
        setTimeout(() => {
      
      
          this.message = 'Updated Message!';
        }, 1000);
      }
    }
  });
</script>

In this example, when the button is clicked, only a specific part of the page is updated through Vue.js's data binding mechanism, rather than the entire page. Vue.js will intelligently detect data changes and update only the necessary parts, thus achieving efficient partial refresh.

React.js：

React.js is a JavaScript library developed by Facebook for building user interfaces. It implements efficient partial refresh through the concept of virtual DOM.

Example:

// 使用 Create React App 快速创建 React 项目
// npx create-react-app my-react-app
// cd my-react-app
// npm start

// React 组件代码
import React, { useState } from 'react';

function App() {
  const [message, setMessage] = useState('Hello, React!');

  const updateMessage = () => {
    // 模拟异步更新数据
    setTimeout(() => {
      setMessage('Updated Message!');
    }, 1000);
  };

  return (
    <div>
      <p>{message}</p>
      <button onClick={updateMessage}>Update Message</button>
    </div>
  );
}

export default App;

In this React.js example, useState provided by React Hooks is used to manage the state of the component. When the state changes, React updates the virtual DOM in an efficient manner and only updates the parts that actually changed, thus achieving partial refresh.

Convenience and performance advantages:

Component-based development: Both Vue and React adopt a component-based development model, which splits the interface into small reusable components, which is beneficial to maintenance and the development of complex applications. .
Virtual DOM: React introduces the concept of virtual DOM. By comparing the difference between virtual DOM and actual DOM, it minimizes DOM operations and improves page rendering efficiency.
Responsive data: Vue's data binding and React's state management (such as using Hooks) enable data changes to be automatically reflected in the view, simplifying state management and pages Updated logic.
Life cycle management: Both Vue and React provide life cycle functions, allowing developers to execute specific logic at different stages of the component life cycle to easily control the behavior of the component.
Community support and ecosystem: Both Vue and React have large communities and rich ecosystems, providing many plug-ins and tools to facilitate rapid development by developers.

In general, both Vue and React provide developers with convenient tools and performance advantages, making it easier and more efficient to implement partial refresh. Choosing one of these frameworks often depends on project needs, personal preference, and the experience of your team.

Practice: Creative application of dynamic page refresh

Dynamic page refresh can create interesting and practical effects in specific scenarios. The following are some actual cases showing how to use creative dynamic refresh effects in different situations, and recommending some constructive thinking and practice methods.

1. Real-time data update

Scenario: On a data dashboard that needs to be updated in real time, such as stock quotes, real-time sales data, etc.

Practical method: Use technologies such as WebSocket to obtain server-side data in real time, and update the data on the page through dynamic refresh. Use animation or transition effects to make data changes more smoothly.

2. Live chat

Scenario: In an online chat application, users want to see real-time messages from other users.

Practical method: Use WebSocket or other real-time communication protocols to push new messages to the client, and insert the messages into the chat interface through dynamic refresh. Consider adding animation effects to make the appearance of new messages more prominent.

3. Game dynamic updates

Scenario: In an online multiplayer game, it is necessary to display dynamic information of other players, such as location, status, etc.

Practical method: Use real-time communication technology to push other players’ dynamic information to the client, and update the game screen in real time through dynamic refresh. Improve user experience through animation effects during interactions between players.

4. Real-time map updates

Scenario: In map applications, users want to see real-time traffic conditions, location updates and other information.

Practical method: Use real-time data sources to display the latest map information to users through dynamic refresh. Combined with animation effects, the changes in map elements are smoother and more natural.

5. Live voting or voting

Scenario: In a meeting or event, real-time voting or voting needs to be performed and real-time statistical results displayed.

Practical method: Use real-time communication to dynamically refresh the page when voting or voting changes, and update the display of voting results in real time. Consider using charts or animations to make voting results more vivid.

Ways to think and practice:

Choose the appropriate communication technology: Choose the appropriate communication technology according to the application scenario, such as WebSocket, Server-Sent Events, etc., to ensure real-time performance and efficiency.
Consider user experience: Using animation effects, transition effects, etc. can make page refresh smoother and improve user experience. Avoid refreshing too frequently to avoid affecting performance.
Handle disconnection and error situations: Consider the user's possible disconnection situation and provide friendly prompts or automatic reconnection mechanisms to ensure that users do not experience network problems when refreshing Troubled.
Security considerations: For applications involving real-time communication, ensure data security and use appropriate encryption and authentication mechanisms.
Compatibility: Consider the compatibility of different browsers and devices to ensure that dynamic refresh effects work properly in various environments.

By applying dynamic page refresh in the right scenarios, you can provide a richer and more useful user experience. In practice, constantly trying new technologies and ideas, and iterating based on user feedback are the keys to creating a successful dynamic refresh effect.