ajax post request

AJAX Post Request

When it comes to transferring data between client and server without refreshing the entire page, AJAX is the most popular technique used by developers. AJAX stands for Asynchronous JavaScript And XML. Post request is one of the HTTP methods used to send data to the server. In this method, data is sent in the body of the request.

How to Make an AJAX Post Request

To make an AJAX post request, we need to use the XMLHttpRequest object which is built into most modern browsers. Here's how to make an AJAX post request:

var xhr = new XMLHttpRequest();
xhr.open('POST', 'url', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(JSON.stringify(data));

• xhr: This is the XMLHttpRequest object which we'll use to make the request.
• open: This method initializes a request. It takes three arguments:
• method: This is the HTTP method we want to use (in this case, POST).
• url: This is the URL we want to send the request to.
• async: This specifies whether the request should be asynchronous or not.
• setRequestHeader: This method sets the value of an HTTP request header. In this case, we're setting the Content-Type header to application/json.
• send: This method sends the request to the server. If we want to send data along with the request, we can pass it as an argument. In this case, we're sending JSON data using the stringify method.

Once the request is sent, we can listen for the response using the onreadystatechange event. Here's an example:

xhr.onreadystatechange = function() {
  if (xhr.readyState === XMLHttpRequest.DONE) {
    if (xhr.status === 200) {
      console.log(xhr.responseText);
    } else {
      console.log('Error: ' + xhr.status);
    }
  }
};

• onreadystatechange: This event is fired whenever the readyState property changes.
• readyState: This property represents the state of the request. There are five possible values: UNSENT (0), OPENED (1), HEADERS_RECEIVED (2), LOADING (3), and DONE (4).
• status: This property represents the HTTP status code returned by the server.
• responseText: This property contains the response from the server.

That's how to make an AJAX post request using JavaScript. There are also libraries like jQuery and Axios which make it easier to make AJAX requests.

Conclusion

AJAX post requests are a powerful way to send data to the server without refreshing the entire page. They allow for a more seamless user experience, and can be used to create dynamic web applications. By using the XMLHttpRequest object and listening for the onreadystatechange event, we can make AJAX post requests in JavaScript.