JS/HTML onChange

Question

with similar question. :)

<input type="text" name="npcolor" id="npcolor" size="9" maxlength="9" value="<?=$userinfo->npcolor?>" onchange="change_npcolor()" readonly />
<input type="text" ID="np_sample" size="2" value="" readonly style="background-color:<?=$userinfo->npcolor?>" />
<input type="button" onclick="pickerPopup202('npcolor','np_sample');" value="Change" />

function pickerPopup202 is changing npcolor, but when npcolor is changed it don't call change_npcolor(). When I put extra button that call change_npcolor it works. I tried also:

document.getElementById("npcolor").onchange='change_npcolor()';

without success.

P.S. JS that changes npcolor (pickerPopup202) isnt mine, and ALL code is at one line, so i cant really mod it.

chage event doesn't fire on input, when its value is changed via js. — kirilloid
– kirilloid, Commented Feb 19, 2011 at 11:45

Vincent · Accepted Answer · 2011-02-19 11:43:32Z

2

When you change the value dynamically, the onchange event doen't fire. You need to call the change_npcolor() method yourself. You could also call document.getElementById("npcolor").onchange(). (This is less efficient, but more flexible when the event handler may change eventually.)

You cannot change the event listener by just adding a string with javascript code to the onchange property. You can do it like this, however:

document.getElementById("npcolor").onchange = function(){
   change_npcolor();
}

answered Feb 19, 2011 at 11:43

Vincent

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2 Comments

Vincent Over a year ago

You should avoid two elements with the same id, since getElementById might not work properly in that case. What exactly is te problem?

CappY Over a year ago

With a lot of code dividing i modified js. The orig. code was 1 line, 4k symbols. Now it's 120 lines. :) I wanted use onChange if some day i decide to change Color Picker, i just replace it, not modify it again.

Senjuti Mahapatra · Accepted Answer · 2017-02-22 09:47:59Z

0

document.getElementById("npcolor").onchange='change_npcolor()';

here you have change_color() as a string but this is not correct syntax.

Instead of that you can use

document.getElementById("npcolor").onchange=change_ncolor;

Because the change_ncolor works as an object.

edited Feb 22, 2017 at 9:47

Senjuti Mahapatra

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answered Feb 22, 2017 at 9:24

Mammu yedukondalu

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