getElementByName

softengilker · #1 07-27-2005, 03:17 AM

I am trying to get a check box element by its name with the code below:

var element = document.Form1.getElementByName( 'myRepeater:_ctl' + i + ':myProjectCheck' );

But this code gives error. Where is the fault?

Is there any other way of it?

**Kor** · #2 07-27-2005, 03:24 AM

the correct syntax is getElementsByName(name) and it returns a collection of elements with the same name, so that furthermore, the reference by index is necessary.

More than that, there is no need to specify the form as reference.

document.getElementsByName( 'elementname')[0];

and if there are more elements with the same name
document.getElementsByName( 'elementname')[1];
document.getElementsByName( 'elementname')[2];
....

duke_okc · #3 12-29-2006, 12:29 PM

I remember reading somewhere that the name attribute is only valid for a limited set of HTML elements and therefore getElementsByName() is only applicable to those elements. Can someone tell me which elements are those please? I am really intrested to know if getElementsByName() would work for radio element but it would be nice to know the entire list. Thanks.

toicontien · #4 12-29-2006, 12:37 PM

The name attribute really only applies to form controls, like INPUT, SELECT, BUTTON and TEXTAREA. If you want to get one specific tag, the use document.getElementById('foo'), that's assuming you give your form controls unique IDs too. You can also do something like below:

HTML Code:

<input type="text" name="txt1" onclick="doSomething(this);">
<input type="text" name="txt2" value="Yeah buddy!!!">
<script type="text/javascript">
function doSomething(obj) {
  // The obj variable in this case refers to an INPUT element. All form elements have
  // a javascript property called form, which is a node reference to the FORM element
  // that contains the INPUT element. The FORM element then has a javascript
  // property called elements that is an integer indexed array of all the FORMs controls,
  // and also an associative array of those FORM controls where the control name is
  // the index you use to refer to the control.
  
  alert(obj.form.elements['txt2'].value);
}
</script>

duke_okc · #5 12-29-2006, 12:52 PM

Quote:

Originally Posted by toicontien

The name attribute really only applies to form controls, like INPUT, SELECT, BUTTON and TEXTAREA.

I am having trouble accessing the input type radio with getElementsByName. I thought the input type radio is part of form control? If thats the case, then shoud I be able to use getElementsByName or not. Lets say, on a form, I have an html code like this:

Code:

<p class="text_boxes">
   <fieldset id="areaFieldSet"><legend id="areaLegend">Select one of the following</font></legend>
   <label class="labels"><input name="radArea" id="radArea" type="radio"
    onclick="areaSelection('WholeState');"/>Whole State</label>
   <label class="labels"><input name="radArea" id="radArea" type="radio"
    onclick="areaSelection('Area');"/>Area</label>
   <label class="labels"><input name="radArea" id="radArea" type="radio"
    onclick="areaSelection('County');"/>County</label>
     </fieldset>
   </p>

I try to access it like this:
document.getElementsByName('radArea')[0];
document.getElementsByName('radArea')[1]; etc...
but it does not work?.....

_Aerospace_Eng_ · #6 12-29-2006, 01:21 PM

I'm not sure how you are accessing the radios. It sounds like you are trying to access them even before the page is loaded. This works fine

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
<script type="text/javascript">
window.onload = function()
{
	var radios = document.getElementsByName('radArea');
	for(var i = 0; i < radios.length; i++)
	{
		alert(radios[i].onclick);
	}
}
</script>
</head>
<body>
<form>
	<fieldset id="areaFieldSet">
	<p class="text_boxes">
		<legend id="areaLegend">Select one of the following</legend>
		<label class="labels">
		<input name="radArea" type="radio"
    onclick="areaSelection('WholeState');"/>
		Whole State</label>
		<label class="labels">
		<input name="radArea" type="radio"
    onclick="areaSelection('Area');"/>
		Area</label>
		<label class="labels">
		<input name="radArea" type="radio"
    onclick="areaSelection('County');"/>
		County</label>
	</p>
	</fieldset>
</form>
</body>
</html>

Also a fieldset can't go in a paragraph.

duke_okc · #7 12-29-2006, 01:53 PM

Quote:

Originally Posted by _Aerospace_Eng_

I'm not sure how you are accessing the radios. It sounds like you are trying to access them even before the page is loaded.

Thanks for replying. I am accessing the radios after the page is loaded. What I really wanted to do was to check and see if radio button was selected or not. I was trying to do it like this:

Code:

var e=document.getElementByName('radDat');
        if  !( e[0].checked == true ){
       //do something;
      //rest of the code;
      }

Does it support checked?

felgall · #8 12-29-2006, 03:12 PM

var e=document.getElementsByName('radDat');
if (!e[0].checked){
// first radio button is not checked ;
}

duke_okc · #9 12-29-2006, 05:18 PM

Thank you guys for all the suggestions! I will work on this when I get back from 4 days weekend. See you guys next year....Happy New Year everyone...

konithomimo · #10 12-29-2006, 05:23 PM

Quote:

Originally Posted by softengilker

I am trying to get a check box element by its name with the code below:

var element = document.Form1.getElementByName( 'myRepeater:_ctl' + i + ':myProjectCheck' );

But this code gives error. Where is the fault?

Is there any other way of it?

As Kor said, it seems you are meaning to use getElementsByName(). There is a function called getElementByName(), but it does not work as intended in most browsers. It works properly in IE, but in better browsers, such as Mozilla, it will search both the name and ID attributes of each element, which can result in you getting the wrong element.

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