POST Request with Fetch API?

Question

I know that with the new Fetch API (used here with ES2017\'s async/await) you can make a GET request like this:

async getData() {
          


        

Answer 1

Here is a complete example: After spending hours tinkering with incomplete code snippets I finally managed to post some json from javascript, pick it up using php on a server, added a data field and finally updated the original web page. Here is the HTML, the PHP and the JS. My thanks to everyone who posted the original code fragments collected here. Similar code is on-line here: https://www.nbest.co.uk/Fetch/index.php

  
  
  



Javascript Fetch Example
Save this to index.php and view this page in your browser.

Press Me

This is the JSON before the fetch.
This is the JSON after the fetch.







// Save this as fetch.js --------------------------------------------------------------------------

function success(json) {
  document.getElementById('after').innerHTML = "AFTER: " + JSON.stringify(json);
  console.log("AFTER: " + JSON.stringify(json));
} // ----------------------------------------------------------------------------------------------

function failure(error) {
  document.getElementById('after').innerHTML = "ERROR: " + error;
  console.log("ERROR: " + error);
} // ----------------------------------------------------------------------------------------------

function myButtonClick() {
  var url    = 'json.php';
  var before = {foo: 'Hello World!'};

  document.getElementById('before').innerHTML = "BEFORE: " + JSON.stringify(before);
  console.log("BEFORE: " + JSON.stringify(before));

  fetch(url, {
    method: 'POST', 
    body: JSON.stringify(before),
    headers:{
      'Content-Type': 'application/json'
    }
  }).then(res => res.json())
  .then(response => success(response))
  .catch(error => failure(error));
} // ----------------------------------------------------------------------------------------------