如何在匿名函数javascript中实现函数的不同行为

Question

I am new to JavaScript and I want to use send_request function twice, but with different behaviour. Element with name button1 should show response on the element, whereas button2 not.

  function send_request(url) {
    var xhr = new XMLHttpRequest();
    xhr.open('POST', url, true);
    xhr.send('data=test');
    xhr.onload = function () {document.getElementById('reply').innerHTML = xhr.responseText;};
  }
  document.getElementById('button1').addEventListener('click', function() { send_request("/data.php"); });
  document.getElementById('button2').addEventListener('click', function() { send_request("/clear_data.php"); });

Is it possible?

Answer 1

You could give send_request another parameter, a function that's called with the responseText, so you could pass one function that assigns to reply, and another function that does whatever you want instead:

function send_request(url, callback) {
  var xhr = new XMLHttpRequest();
  xhr.open('POST', url, true);
  xhr.send('data=test');
  xhr.onload = () => callback(xhr.responseText);
}
document.getElementById('button1').addEventListener('click', function() {
  send_request("/data.php", (responseText) => {
    document.getElementById('reply').innerHTML = responseText;
  });
});
document.getElementById('bitton2').addEventListener('click', function() {
  send_request("/clear_data.php", (responseText) => {
    console.log('bitton 2 response: ' + responseText);
  });
});