This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
Note: Since Firefox 57 (initially Nightly-only), both the
_content variants are only available to chrome (privileged) code, and not available to the web anymore.
Returns a Window object for the primary content window. This is useful in XUL windows that have a
type="content-primary" attribute on it — the most famous example is Firefox main window,
browser.xul. In such cases,
content returns a reference to the
Window object for the document currently displayed in the browser. It is a shortcut for
In unprivileged content (webpages),
content is normally equivalent to top (except in the case of a webpage loaded in a sidebar,
content still refers to the
Window of the currently selected tab).
Note: Some examples use
_content instead of
content. The former has been deprecated for a long time, and you should use
content in any new code.
var windowObject = window.content;
Executing the following code in a chrome XUL window with a
<browser type="content-primary"/> element in it draws a red border around the first div on the page currently displayed in the browser:
content.document.getElementsByTagName("div").style.border = "solid red 1px";