Web Scraping with Vue 3 + Vite: Fundamentals and Practical Guide

Abstract: This blog will introduce how to use Vue 3 and Vite framework to practice web crawling. We will first discuss the basic principles of crawlers, including request methods, request addresses, request headers, request bodies, and responses. Then, we'll explore how to combine Vue 3 and the Vite framework to build a simple crawler application, and provide some practical sample code and tips.

Introduction

A web crawler is a program that automatically obtains web content and is often used for data collection, information analysis, and automation tasks. Vue 3 is a popular JavaScript framework that provides modern development tools and convenient component development methods. Vite is a fast build tool that provides an instant development experience and efficient packaging results. Combining Vue 3 and Vite, we can easily build a web crawler application.

Basic principles of crawlers

Before we start building a crawler application, we need to understand some basic principles of crawlers. The following are the key concepts of crawlers:

1. Request method: The crawler sends a request through the HTTP protocol to obtain the content of the target web page. Common request methods are GET and POST, where GET is used to obtain data and POST is used to submit data.

2. Request address: The request address is the URL of the target web page. The crawler needs to provide the correct URL to send the request and obtain the corresponding data.

3. Request header: The request header contains additional request information, such as User-Agent, Referer, etc. In some cases, the server may determine the legitimacy of the request and the format of the returned data based on the request header information.

4. Request body: For POST requests, the request body contains the data that needs to be submitted. The crawler can send data to the server through the request body.

5. Response: After the server receives the request, it will return a response. The response contains the content of the target web page, as well as some additional response information, such as status code, response headers, etc.

After understanding these basic principles, we can start building a crawler application based on Vue 3 and Vite.

Scraping with Vue 3 + Vite

Step 1: Create a Vue project

First, we need to create a new Vue project using the Vue CLI. Open a terminal and execute the following command:

$ npm init @vitejs/app my-crawler-app --template vue
$ cd my-crawler-app
$ npm install

This will create a my-crawler-appnew directory called and install the Vue project's dependencies.

Step 2: Create the crawler component

Next, we will create a crawler component that sends network requests and displays the content of the response.

srcCreate a file named in the directory and Crawler.vueadd the following code:

<template>
  <div>
    <button @click="fetchData">发送请求</button>
    <div v-if="response">{
   
   { response }}</div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      response: null,
    };
  },
  methods: {
    async fetchData() {
      const url = 'https://example.com'; // 替换为目标网页的URL
      const response = await fetch(url);
      const data = await response.text();
      this.response = data;
    },
  },
};
</script>

In the above code, we define a click button. When the button is clicked, the fetchDatamethod is called to send a network request. fetchDataMethod fetchsends a GET request using a function and saves the text content of the response in responsea variable.

Step 3: Introduce crawler components

Open src/App.vuethe file and replace its contents with the following code:

<template>
  <div>
    <h1>网络爬虫应用程序</h1>
    <Crawler />
  </div>
</template>

<script>
import Crawler from './Crawler.vue';

export default {
  components: {
    Crawler,
  },
};
</script>

The above code introduces the crawler component into the main application and displays it on the page.

Step 4: Run the application

After saving all files, go back to the terminal and execute the following command to run the application:

$ npm run dev

This will start the development server and open the application in the browser. You will see a page titled "Web Crawler Application" and a button to send a request.

Step 5: Verify crawler functionality

Now you can click on the "Send Request" button and the crawler will send a GET request to https://example.comand display the content of the response. You can modify fetchDatathe URL in the method according to actual needs to obtain different web content.

in conclusion

This blog introduces how to build a simple web crawler application using Vue 3 and Vite. We discussed the basic principles of crawlers, including request methods, request addresses, request headers, request bodies, and responses. Then, we demonstrated how to send a network request in Vue 3 and display the content of the response by creating a crawler component.

Keep in mind that when using crawlers in actual development, you should comply with the website's terms of use and policies. Legal and compliant crawler behavior is crucial to protecting the online ecosystem and personal privacy. thanks for reading!