files/en-us/web/api/document/createelementns/index.md
{{APIRef("DOM")}}
Creates an element with the specified namespace URI and qualified name.
To create an element without specifying a namespace URI, use the {{DOMxRef("Document.createElement()", "createElement()")}} method.
createElementNS(namespaceURI, qualifiedName)
createElementNS(namespaceURI, qualifiedName, options)
namespaceURI
qualifiedName
options {{Optional_Inline}}
: An optional ElementCreationOptions object containing a single property named is, whose value is the tag name for a custom element previously defined using customElements.define().
For backwards compatibility, some browsers allow you to pass a string here instead of an object, where the string's value is the custom element's tag name.
See Extending native HTML elements for more information on how to use this parameter.
The new element will be given an is attribute whose value is the custom element's tag name. Custom elements are an experimental feature only available in some browsers.
The new {{DOMxRef("Element")}}.
NamespaceError {{domxref("DOMException")}}
namespaceURI value is not a valid namespace URI.InvalidCharacterError {{domxref("DOMException")}}
qualifiedName value is not a valid XML name; for example, it starts with a number, hyphen, or period, or contains characters other than alphanumeric characters, underscores, hyphens, or periods.This creates a new <div> element in the {{Glossary("XHTML")}} namespace and
appends it to the vbox element. Although this is not an extremely useful XUL document, it does demonstrate the use of
elements from two different namespaces within a single document:
<?xml version="1.0"?>
<page xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
xmlns:html="http://www.w3.org/1999/xhtml"
title="||Working with elements||"
onload="init()">
<script><![CDATA[
let container;
let newDiv;
let textNode;
function init() {
container = document.getElementById("ContainerBox");
newDiv = document.createElementNS("http://www.w3.org/1999/xhtml", "div");
textNode = document.createTextNode(
"This is text that was constructed dynamically with createElementNS and createTextNode then inserted into the document using appendChild.",
);
newDiv.appendChild(textNode);
container.appendChild(newDiv);
}
]]></script>
<vbox id="ContainerBox" flex="1">
<html:div>
The script on this page will add dynamic content below:
</html:div>
</vbox>
</page>
[!NOTE] The example given above uses inline script which is not recommended in XHTML documents. This particular example is actually an XUL document with embedded XHTML, however, the recommendation still applies.
{{Specifications}}
{{Compat}}