.click() fails after dom change

问题:

I searched on web but I didn't find any answer since this "problem" is not the usual one about the difference between .on() and .click(). With jquery 2.1.3 the click function is a shortand for on.("click", handler) so it should fire a function (or wathever) after the dom is changed. But this works only if I use .on(). Why? (Example below)

$('#button1').click(function() {
    $('div').html("<p id="button2">Hello</p>");
});

$('#button2').click(function() {
    alert(0); //THIS DOESN'T WORK
});

$(body).on("click", "#button2", function() {
    alert(0); //THIS WORKS!
});

回答1:

But this works only if I use .on().

First of all , you should realize that :

If

$('#button2').click(function() {
    alert(0); 
});

comes after

$('#button1').click(function() {
    $('div').html("<p id="button2">Hello</p>");
});

like :

   $('#button1').click(function() {
        $('div').html("<p id="button2">Hello</p>");
        $('#button2').click(function() {
          alert(0); 
      });
    });

Then it WILL work.

the thing which you did in the last code is attaching the handler to the body element which is working because of event propagation.

your code is working beacuse on allows you to do selector matching + attaching single handler to the body element.

回答2:

$('#button1').click(function() {
    $('div').html("<p id='button2'>Hello</p>");
});

$('#button2').click(function() {
    alert(0); //THIS DOESN'T WORK
});

$(document).on("click", "#button2", function() {
    alert(0); //THIS WORKS!
});

This is correct code

https://jsfiddle.net/hhe3npux/

回答3:

The answer is if you added data dynamically, then you must use .on function. With this code, you can use event delegation concept by using the code that you mention at last. Since the DOM are not registered yet, the .click handler cant capture the new DOM element.