In front-end development, we often encounter the problem of cross-domain access. As a widely used front-end framework, Vue often encounters this problem. In this article, we will introduce cross-domain access issues in Vue and their solutions.

What is cross-domain access?

Simply put, cross-domain access refers to a Web page in one domain accessing resources in another domain. For example, if you request resources under the domain name http://www.example2.com from a page under the domain name http://www.example.com, cross-domain access will occur.

Cross-domain access issues in Vue

When we use Vue to send Ajax requests, if the requested URL is different from the domain name of the current page, cross-domain access issues will occur. In this case, the browser will send an OPTIONS request to the server to ask the server whether it supports cross-domain access. Only if the server returns a response header that allows cross-domain access, the Ajax request can be completed normally.

Solution

There are several ways to solve the problem of cross-domain access in Vue.

1. Using a proxy

Vue-cli provides a way to solve cross-domain access by configuring a proxy. We can achieve cross-domain access by configuring the proxy in the index.js file in the config directory.

The specific steps are as follows:

Add the proxyTable attribute to the dev object in the index.js file.

proxyTable: {
  // 將所有以/api開頭的請求代理到http://localhost:3000上
  '/api': {
    target: 'http://localhost:3000',
    changeOrigin: true,
    pathRewrite: {
      '^/api': ''
    }
  }
}

At this point, when we request a URL starting with /api, it will be proxied to http://localhost:3000. The changeOrigin attribute is set to true to indicate that the origin field in the request header needs to be modified when making a cross-domain request. The pathRewrite attribute indicates that /api in the request path is replaced with an empty string.

2.JSONP (only applicable to GET requests)

JSONP is a way to implement cross-domain requests by dynamically adding script tags on the page. We can solve the cross-domain access problem by using JSONP in Vue.

The specific steps are as follows:

Install jsonp library

npm install jsonp --save

Use JSONP in the page

import jsonp from 'jsonp'

jsonp(url, options, (err, data) => {
  if (!err) {
    // 處理數據
  }
})

url represents the requested URL, options represents the requested parameters, The data in the callback function (err, data) is the returned data.

3.CORS

CORS is a standard developed by W3C that allows the server to decide whether to allow cross-domain access. We can make some configurations on the server side to make the server support CORS. The configuration method varies from server to server, so I won’t go into details here.

When using CORS, we need to use the withCredentials attribute in Vue to achieve cross-domain access. The specific steps are as follows:

Enable the withCredentials attribute in Vue

Vue.http.options.credentials = true

The withCredentials attribute indicates whether cross-domain requests are allowed to send user credential information such as cookies.

Conclusion

There are many ways to solve cross-domain access problems in Vue, but each method has its advantages and disadvantages. Using the proxy method can well solve the cross-domain access problem in Vue. JSONP is only suitable for GET requests. When using the CORS method, some configuration is required on the server side. We should choose the appropriate solution based on our actual situation.

The above is the detailed content of Solution to cross-domain access problem in Vue. For more information, please follow other related articles on the PHP Chinese website!