XMLHttpRequest for POST request code example

Example 1: javascript send post request

let data = {element: "barium"};

fetch("/post/data/here", {
  method: "POST", 
  body: JSON.stringify(data)
}).then(res => {
  console.log("Request complete! response:", res);
});


// If you are as lazy as me (or just prefer a shortcut/helper):

window.post = function(url, data) {
  return fetch(url, {method: "POST", body: JSON.stringify(data)});
}

// ...

post("post/data/here", {element: "osmium"});

Example 2: xhr post send

var xhr = new XMLHttpRequest();
var params = 'field1='+postfield1+'&field2='+postfield2;
xhr.open('POST', 'http://exmaple.com', true);

//Send the proper header information along with the request
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

xhr.onload = function() {//Call a function when the state changes.
    if(xhr.status == 200) {
        alert(this.responseText);
    }
}
xhr.send(params);

Example 3: javascript http request

// Use these functions:

function _GET_REQUEST(url, response) {
  var xhttp;
  if (window.XMLHttpRequest) {
    xhttp = new XMLHttpRequest();
  } else {
    xhttp = new ActiveXObject("Microsoft.XMLHTTP");
  }

  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      response(this.responseText);
    }
  };

  xhttp.open("GET", url, true);
  xhttp.send();
}

function _POST_REQUEST(url, params, response) {
  var xhttp;
  if (window.XMLHttpRequest) {
    xhttp = new XMLHttpRequest();
  } else {
    xhttp = new ActiveXObject("Microsoft.XMLHTTP");
  }

  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      response(this.responseText);
    }
  };

  xhttp.open("POST", url, true);
  xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  xhttp.send(params);
}


// Use like:
_GET_REQUEST('http://url.com', (response) => {
	// Do something with variable response
  	console.log(response);
});
_POST_REQUEST('http://url.com', 'parameter=sometext', (response) => {
	// Do something with variable response
  	console.log(response);
});

Example 4: What XMLHttpRequest method must be used to send a POST request to the server?

var url = "get_data.php";
var params = "lorem=ipsum&name=binny";
http.open("POST", url, true);

//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.setRequestHeader("Content-length", params.length);
http.setRequestHeader("Connection", "close");

http.onreadystatechange = function() {//Call a function when the state changes.
	if(http.readyState == 4 && http.status == 200) {
		alert(http.responseText);
	}
}
http.send(params);