How to delete server files in javascript

In web development, we often need to use file upload and delete operations. In the front-end, we can use JavaScript to implement some simple file upload and delete operations, but deleting files on the server usually requires the help of a back-end language. But in some specific cases, we can also use JavaScript to delete files on the server.

Before using JavaScript to delete files on the server, there are several things to note:

1. There needs to be a server-side interface that can receive and process requests to delete files;
2. You need to have sufficient permissions to perform the deletion operation, otherwise it will be rejected by the server.

Next, let’s introduce some how to use JavaScript to delete files on the server.

Method 1: Use the XMLHttpRequest object to send an HTTP request

In JavaScript, we can use the XMLHttpRequest object to send an HTTP request to the server. We can send an HTTP DELETE request to the server to delete a specified file.

The following is a sample code that uses XMLHttpRequest to delete a file from the server:

function deleteFile(fileUrl) {
  var xhr = new XMLHttpRequest();
  xhr.open("DELETE", fileUrl, true);
  xhr.send();
  
  xhr.onload = function() {
    console.log("File deleted successfully.");
  };
  
  xhr.onerror = function() {
    console.error("Delete request failed.");
  };
}

In this sample code, we pass the URL of the file as a parameter and create an XMLHttpRequest object. We use the open() method to specify the request method (DELETE), the requested URL (fileUrl), and whether to send the request asynchronously.

After sending the request, we can use the onload and onerror event handlers to handle the response to the request. If the file is successfully deleted, we will output "File deleted successfully." in the console, otherwise we will output "Delete request failed.".

It should be noted that if the server does not support the HTTP DELETE method, files cannot be deleted using this method.

Method 2: Use fetch to send HTTP requests

In addition to using the XMLHttpRequest object to send HTTP requests, we can also use the fetch method to send HTTP requests. fetch is a new web API that can handle HTTP requests easily. The following is a sample code that uses fetch to delete a file on the server:

function deleteFile(fileUrl) {
  fetch(fileUrl, { method: "DELETE" })
    .then(function(response) {
      console.log("File deleted successfully.");
    })
    .catch(function(error) {
      console.error("Delete request failed.");
    });
}

In this sample code, we pass the URL of the file as a parameter and send an HTTP DELETE request to the server using the fetch method. If the file is successfully deleted, we will output "File deleted successfully." in the console, otherwise we will output "Delete request failed.".

It should be noted that the compatibility of the fetch method is not good enough and currently only supports modern browsers such as Firefox, Chrome and Edge.

Issues that need attention

When using JavaScript to delete files on the server, we need to pay attention to the following issues:

1. Requires server-side cooperation to achieve file deletion Operation;
2. Must have sufficient permissions to delete files;
3. is only suitable for deletion operations of small files. You may encounter performance and stability issues when processing large files.

Summary

In this article, we introduced two methods of deleting files on the server using JavaScript. Although this method is generally only suitable for small files, it is also very useful in some specific development scenarios. In actual development, we should choose the most suitable method according to the specific situation.

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