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Re: Why does savepng workl with eventlistener but not by call from form?

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JJ wrote:

> On Fri, 11 Nov 2016 06:35:50 -0800 (PST), jonas.thornvall@gmail.com wrote:
>> Could you explain
>> document.getElementById("pushit").addEventListener("click",savepng);
> 
> It attach an event handler (function) to the "click" event of the element
> with ID "pushit".
> 
> The code produces the same functionality as below code

No.

> (but different method of attaching an event handler). In this case, it
> assign a function to an event handler variable. This is an older method.
> 
>   document.getElementById("pushit").onclick=savepng;

AISB, at least in Chromium this replaces the first event listener that had 
not been added with addEventListener(), if any, so that the referred 
function is called *after* all other event listeners.  Try this:

  var obj = document.getElementById("pushit");
  obj.onclick = function () { console.log(1); };
  obj.addEventListener("click", function () { console.log(2); }, false);
  obj.onclick = function () { console.log(3); };

When you click the element (and navigation to another document is not the 
default action), the console would show “2” followed by “3”.
 
> When you click something, a "click" event is generated to the clicked
> element. All "click" event's handler functions for that element will be
> called, regardless of their function name.

The proper term is event _listener(s)_.

And as the “click” event bubbles, if its propagation upwards in the document 
tree is not stopped before (Event::stopPropagation()), the “click” event 
listeners of ancestor elements, if any, are triggered first in tree order, 
and then in listener registration order.
 
-- 
PointedEars
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Why does savepng workl with eventlistener but not by call from form? jonas.thornvall@gmail.com - 2016-11-10 14:35 -0800
  Re: Why does savepng workl with eventlistener but not by call from form? jonas.thornvall@gmail.com - 2016-11-10 15:47 -0800
    Re: Why does savepng workl with eventlistener but not by call from form? JJ <jj4public@vfemail.net> - 2016-11-11 21:05 +0700
      Re: Why does savepng workl with eventlistener but not by call from form? jonas.thornvall@gmail.com - 2016-11-11 06:35 -0800
        Re: Why does savepng workl with eventlistener but not by call from form? JJ <jj4public@vfemail.net> - 2016-11-11 22:01 +0700
          Re: Why does savepng workl with eventlistener but not by call from form? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-11-11 16:21 +0100
      Re: Why does savepng workl with eventlistener but not by call from form? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-11-11 16:08 +0100
        Re: Why does savepng workl with eventlistener but not by call from form? Scott Sauyet <scott@sauyet.com> - 2016-11-26 21:09 +0000
          Re: Why does savepng workl with eventlistener but not by call from form? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-11-26 22:47 +0100
            Re: Why does savepng workl with eventlistener but not by call from form? "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-11-27 00:11 +0100
              Re: Why does savepng workl with eventlistener but not by call from form? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-11-27 00:57 +0100
                Re: Why does savepng workl with eventlistener but not by call from form? Scott Sauyet <scott@sauyet.com> - 2016-11-27 01:08 +0000
                Re: Limit number of function parameters (was:Why does savepng workl with eventlistener but not by call from form?) "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-11-28 18:17 +0100
                Re: Limit number of function parameters (was:Why does savepng workl with eventlistener but not by call from form?) Scott Sauyet <scott@sauyet.com> - 2016-11-29 02:15 +0000
                Re: Limit number of function parameters "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-12-02 20:24 +0100
                Re: Limit number of function parameters Scott Sauyet <scott@sauyet.com> - 2016-12-03 01:58 +0000

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