Menu
Trying determinate DOM Element by simple check
isElement = SomeThing instanceof Element
works in main document, but not on (all?) nodes in iframe.
Example output (Google Chrome): (mdiv is DIV in main document, idiv is DIV in iframe)
OMGWTF
ok: mdiv instanceof Element ... true ... [object HTMLDivElement]
ok: mdiv instanceof Object ... true ... [object HTMLDivElement]
ko: idiv instanceof Element ... false ... [object HTMLDivElement]
KO : idiv instanceof Object ... false ... [object HTMLDivElement]
There are different javascript implementations for main document and for iframe documents ???
Please explain me what's wrong.
Example: (http://www.sbmintegral.sk/GITHUB/OMGWTF/obalka.xhtml)
Code: obalka.xhtml (main document)
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Obalka</title>
</head>
<body>
<div id="auto_filled_commands_container">
MAIN div id="auto_filled_commands_container"<br/>
<iframe id="auto_filled_commands_iframe" src='dopis.xhtml' style="width:98%;height:98%;"/>
</div>
<div>
<textarea id="OMGWTF" style="width:700px;height:200px">
mdiv = document.getElementById("auto_filled_commands_container");
ifram = document.getElementById("auto_filled_commands_iframe");
idiv = ifram.contentDocument.getElementById('auto_filled_commands');
OMGWTF = "OMGWTF \n"
+"ok: mdiv instanceof Element ... "+(mdiv instanceof Element)+" ... "+mdiv+"\n"
+"ok: mdiv instanceof Object ... "+(mdiv instanceof Object)+" ... "+mdiv+"\n"
+"ko: idiv instanceof Element ... "+(idiv instanceof Element)+" ... "+idiv+"\n"
+"KO : idiv instanceof Object ... "+(idiv instanceof Object)+" ... "+idiv+"\n"
;
document.getElementById('result_txta').value = OMGWTF;
</textarea>
<br/><input type="button" value="Eval code in upper textarea (to bypass possible developer tools error)" onclick="
eval(document.getElementById('OMGWTF').value);
"/><b>(2.)</b><br/>
<textarea id="result_txta" style="width:700px;height:100px">
</textarea>
</div>
</body>
</html>
Code: Dopis.xhtml (inner frame document)
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Dopis</title>
</head>
<body>
<div id="auto_filled_commands">
IFRAME div id="auto_filled_commands"<br/>
<div id="afc_formular">
IFRAME div id="afc_formular"<br/>
<input id="cmnd" type="text" value="input id='cmnd'" />
<br/><input type="button" value="Click to get browser userAgent" onclick="
var preEl = this.ownerDocument.getElementById('navUserAgent');
var cdataEl = preEl.firstChild || preEl; /* IE don't know CDATA ?! */
cdataEl.textContent=navigator.userAgent;
"/><b>(1.)</b>
<pre id="navUserAgent"><![CDATA[
]]></pre>
</div>
</div>
</body>
</html>
Results image (in IE, Chrome, Firefox, Opera) 
(source: sbmintegral.sk)
879
HTMLElement : Element. HTMLElement represents an element in the HTML document tree. HTMLElement is the base type for HTMLDivElement, HTMLSpanElement, HTMLImageElement, and many others.
You could try if you wish instanceof Object , because the function will be an instance of Object , or just check explicitly for typeof === "function" , because Node and HTMLElement are both native object functions. When you call isElement(0) , it returns 0, not false...
To check if an element is connected or attached to the DOM or the document object ( or otherwise called the context ), you can use the isConnected property in the element's object in JavaScript. The isConnected element property returns boolean true if it connected to the DOM ( document object) and false if not.
There are different javascript implementations for main document and for iframe documents ???
Yes. The iframe has its own environment with its own globals. Try
var iwin = ifram.contentWindow;
idiv instanceof iwin.HTMLElement; // true
idiv instanceof iwin.Object; // true
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
