Window object[Global=Window,
Exposed=Window,
LegacyUnenumerableNamedProperties]
interface Window : EventTarget {
// the current browsing context
[Unforgeable] readonly attribute WindowProxy window;
[Replaceable] readonly attribute WindowProxy self;
[Unforgeable] readonly attribute Document document;
attribute DOMString name;
[PutForwards=href, Unforgeable] readonly attribute Location location;
readonly attribute History history;
readonly attribute CustomElementRegistry customElements;
[Replaceable] readonly attribute BarProp locationbar;
[Replaceable] readonly attribute BarProp menubar;
[Replaceable] readonly attribute BarProp personalbar;
[Replaceable] readonly attribute BarProp scrollbars;
[Replaceable] readonly attribute BarProp statusbar;
[Replaceable] readonly attribute BarProp toolbar;
attribute DOMString status;
void close();
readonly attribute boolean closed;
void stop();
void focus();
void blur();
// other browsing contexts
[Replaceable] readonly attribute WindowProxy frames;
[Replaceable] readonly attribute unsigned long length;
[Unforgeable] readonly attribute WindowProxy? top;
attribute any opener;
[Replaceable] readonly attribute WindowProxy? parent;
readonly attribute Element? frameElement;
WindowProxy? open(optional USVString url = "about:blank", optional DOMString target = "_blank", optional [TreatNullAs=EmptyString] DOMString features = "");
getter object (DOMString name);
// Since this is the global object, the IDL named getter adds a NamedPropertiesObject exotic
// object on the prototype chain. Indeed, this does not make the global object an exotic object.
// Indexed access is taken care of by the WindowProxy exotic object.
// the user agent
readonly attribute Navigator navigator;
[SecureContext] readonly attribute ApplicationCache applicationCache;
// user prompts
void alert();
void alert(DOMString message);
boolean confirm(optional DOMString message = "");
DOMString? prompt(optional DOMString message = "", optional DOMString default = "");
void print();
void postMessage(any message, USVString targetOrigin, optional sequence<object> transfer = []);
void postMessage(any message, optional WindowPostMessageOptions options);
};
Window includes GlobalEventHandlers;
Window includes WindowEventHandlers;
dictionary WindowPostMessageOptions : PostMessageOptions {
USVString targetOrigin = "/";
};windowframesselfThese attributes all return window.
documentReturns the Document associated with window.
defaultViewReturns the Window object of the active document.
The Window object has an associated Document, which is a
Document object. It is set when the Window object is created, and only
ever changed during navigation from the initial
about:blank Document.
The Window object's browsing context is the Window object's associated Document's browsing context. It is either null or a
browsing context.
The window, frames, and self IDL
attributes, on getting, must all return this Window object's browsing
context's WindowProxy object.
The document IDL attribute, on getting, must
return this Window object's associated
Document.
The Document object associated with a Window object can
change in exactly one case: when the navigate algorithm initializes a new Document object for the first page loaded
in a browsing context. In that specific case, the Window object of the
original about:blank page is reused and gets a new Document object.
The defaultView attribute's getter,
when invoked, must run these steps:
If this Document object's browsing
context is null, then return null.
Return this Document object's browsing
context's WindowProxy object.
For historical reasons, Window objects must also have a writable, configurable,
non-enumerable property named HTMLDocument whose value is the
Document interface object.
open( [ url [, target [, features ] ] ] )Opens a window to show url (defaults to about:blank), and returns it.
The target argument gives the name of the new window. If a window exists with that
name already, it is reused. The features argument can be used to influence the
rendering of the new window.
name [ = value ]Returns the name of the window.
Can be set, to change the name.
close()Closes the window.
closedReturns true if the window has been closed, false otherwise.
stop()Cancels the document load.
The window open steps, given a string url, a string target, and a string features, are as follows:
If the event loop's termination nesting level is nonzero, return null.
Let entry settings be the entry settings object.
Let source browsing context be the responsible browsing context specified by entry settings.
If target is the empty string, then set target to "_blank".
Let tokenizedFeatures be the result of tokenizing features.
Let noopener and noreferrer be false.
If tokenizedFeatures contains an entry with
the key "noopener", then set noopener to the result of parsing
tokenizedFeatures["noopener"] as a boolean feature.
If tokenizedFeatures contains an entry with
the key "noreferrer", then set noreferrer to the result of
parsing
tokenizedFeatures["noreferrer"] as a boolean feature.
If noreferrer is true, then set noopener to true.
Let target browsing context and new be the result of applying the rules for choosing a browsing context given target, source browsing context, and noopener.
If there is a user agent that supports control-clicking a link to open it in
a new tab, and the user control-clicks on an element whose onclick handler uses the window.open() API to open a page in an iframe element, the
user agent could override the selection of the target browsing context to instead target a new
tab.
If target browsing context is null, then return null.
If new is true, then set up browsing context features for target browsing context given tokenizedFeatures. [CSSOMVIEW]
Let urlRecord be the URL "about:blank".
If url is not the empty string or new is true, then:
If url is not the empty string, then parse
url relative to entry settings, and set urlRecord to the
resulting URL record, if any. If the parse a URL algorithm failed,
then throw a "SyntaxError" DOMException.
If noreferrer is true, then set request's referrer to "noreferrer".
If urlRecord is "about:blank" and new is true, then
queue a task to fire an event named load at target browsing context's Window
object, with the legacy target override flag set.
Otherwise, navigate target browsing context to request, with the exceptions enabled flag set. If new is true, then replacement must be enabled. The source browsing context is source browsing context. Rethrow any exceptions.
If noopener is true, then return null.
Otherwise, if new is false, set target browsing context's opener browsing context to source browsing context.
If new is true this is done as part of creating a new auxiliary browsing context.
Return target browsing context's WindowProxy object.
The open(url,
target, features) method on Window objects
provides a mechanism for navigating an existing browsing
context or opening and navigating an auxiliary browsing context.
When the method is invoked, the user agent must run the window open steps with url, target, and features.
To tokenize the features argument:
Let tokenizedFeatures be a new ordered map.
Let position point at the first code point of features.
While position is not past the end of features:
Let name be the empty string.
Let value be the empty string.
Collect a sequence of code points that are feature separators from features given position. This skips past leading separators before the name.
Collect a sequence of code points that are not feature separators from features given position. Set name to the collected characters, converted to ASCII lowercase.
Set name to the result of normalizing the feature name name.
While position is not past the end of features and the code point at position in features is not U+003D (=):
If the code point at position in features is U+002C (,), or if it is not a feature separator, then break.
Advance position by 1.
This skips to the first U+003D (=) but does not skip past a U+002C (,) or a non-separator.
If the code point at position in features is a feature separator:
While position is not past the end of features and the code point at position in features is a feature separator:
If the code point at position in features is U+002C (,), then break.
Advance position by 1.
This skips to the first non-separator but does not skip past a U+002C (,).
Collect a sequence of code points that are not feature separators code points from features given position. Set value to the collected code points, converted to ASCII lowercase.
If name is not the empty string, then set tokenizedFeatures[name] to value.
Return tokenizedFeatures.
A code point is a feature separator if it is ASCII whitespace, U+003D (=), or U+002C (,).
For legacy reasons, there are some aliases of some feature names. To normalize a feature name name, switch on name:
screenx"
left".
screeny"
top".
innerwidth"
width".
innerheight"
height".
To parse a boolean feature given a string value:
If value is the empty string, then return true.
If value is a case-sensitive match for yes, then return
true.
Let parsed be the result of parsing value as an integer.
If parsed is an error, then set it to 0.
Return false if parsed is 0, and true otherwise.
The name attribute's getter must run these steps:
If this Window object's browsing context is
null, then return the empty string.
Return this Window object's browsing
context's name.
The name attribute's setter must run these steps:
If this Window object's browsing context is
null, then return.
Set this Window object's browsing context's
name to the given value.
The name gets reset when the browsing context is navigated to another origin.
The close() method must run these steps:
Let current be this Window object's browsing context.
If current is null or its is closing is true, then return.
If all the following are true
then:
Set current's is closing to true.
Queue a task on the DOM manipulation task source to close current.
A browsing context is script-closable if it is an auxiliary
browsing context that was created by a script (as opposed to by an action of the user), or
if it is a top-level browsing context whose session history contains
only one Document.
The closed attribute's getter must return
true if this Window object's browsing context is
null or its is closing is true, and false otherwise.
The stop() method must stop document
loading given this Window object's associated Document.
lengthReturns the number of document-tree child browsing contexts.
Returns the indicated document-tree child browsing context.
The number of document-tree child browsing
contexts of a Window object W is the result of running these
steps:
If W's browsing context is null, then return 0.
Return the number of document-tree child browsing contexts of W's browsing context.
The length IDL attribute's getter must return the
number of document-tree child browsing contexts of this Window
object.
Indexed access to document-tree child browsing contexts is defined through the [[GetOwnProperty]] internal method of the
WindowProxy object.
Window objectReturns the indicated element or collection of elements.
As a general rule, relying on this will lead to brittle code. Which IDs end up mapping to
this API can vary over time, as new features are added to the Web platform, for example. Instead
of this, use document.getElementById() or document.querySelector().
The document-tree child browsing context
name property set of a Window object window is the return value of
running these steps:
If window's browsing context is null, then return the empty list.
Let childBrowsingContexts be all document-tree child browsing contexts of window's browsing context whose browsing context name is not the empty string, in order, and including only the first document-tree child browsing context with a given name if multiple document-tree child browsing contexts have the same one.
Remove each browsing context from childBrowsingContexts whose
active document's origin is not same origin with
window's relevant settings object's origin and whose browsing context
name does not match the name of its browsing context container's name content attribute value.
Return the browsing context names of childBrowsingContexts, in the same order.
This means that in the following example, hosted on https://example.org/, assuming https://elsewhere.example/
sets window.name to "spices", evaluating
window.spices after everything has loaded will yield undefined:
<iframe src=https://elsewhere.example.com/></iframe>
<iframe name=spices></iframe>The Window object supports named
properties. The supported property names of a Window object
window at any moment consist of the following, in tree order according to
the element that contributed them, ignoring later duplicates:
window's document-tree child browsing context name property set;
the value of the name content attribute for all embed,
form, frameset, img, and object elements that
have a non-empty name content attribute and are in a document
tree with window's associated
Document as their root; and
the value of the id content attribute for all HTML
elements that have a non-empty id content attribute and are
in a document tree with window's associated Document as their
root.
To determine the value of a named property
name in a Window object window, the user agent must return the
value obtained using the following steps:
Let objects be the list of named objects of window with the name name.
There will be at least one such object, by definition.
If objects contains a browsing context, then return the
WindowProxy object of the nested browsing context corresponding to the
first browsing context container in tree order whose nested
browsing context is in objects.
Otherwise, if objects has only one element, return that element.
Otherwise return an HTMLCollection rooted at window's associated Document, whose filter matches
only named objects of window with
the name name. (By definition, these will all be elements.)
Named objects of Window object
window with the name name, for the purposes of the above algorithm, consist
of the following:
document-tree child browsing
contexts of window's associated
Document whose name is
name;
embed, form, frameset, img, or
object elements that have a name content attribute whose
value is name and are in a document tree with window's associated Document as their
root; and
HTML elements that have an id content attribute
whose value is name and are in a document tree with window's
associated Document as their
root.
To discard a
Document document:
Set document's salvageable state to false.
Run any unloading document cleanup steps for document that are defined by this specification and other applicable specifications.
Abort document.
Remove any tasks associated with document in any task source, without running those tasks.
Discard all the child browsing contexts of document.
For each session history entry entry with a Document
object equal to document, remove entry's Document
object.
Set document's browsing context to null.
Remove document from the
owner set of each WorkerGlobalScope object whose set contains document.
To discard a browsing context browsingContext, run these steps:
Discard all Document objects for all
the entries in browsingContext's session history.
If browsingContext is a top-level browsing context, then remove browsingContext.
User agents may discard top-level browsing contexts at any time (typically, in
response to user requests, e.g., when a user force-closes a window containing one or more top-level browsing contexts). Other browsing contexts must be discarded once their
WindowProxy object is eligible for garbage collection, in addition to the other
places where this specification requires them to be discarded.
To close a browsing context browsingContext, run these steps:
Prompt to unload browsingContext's active document. If the user refused to allow the document to be unloaded, then return.
Unload browsingContext's active document.
Remove browsingContext from the user interface (e.g., close or hide its tab in a tabbed browser).
Discard browsingContext.
User agents should offer users the ability to arbitrarily close any top-level browsing context.
To allow Web pages to integrate with Web browsers, certain Web browser interface elements are exposed in a limited way to scripts in Web pages.
Each interface element is represented by a BarProp object:
[Exposed=Window]
interface BarProp {
readonly attribute boolean visible;
};locationbar . visibleReturns true if the location bar is visible; otherwise, returns false.
menubar . visibleReturns true if the menu bar is visible; otherwise, returns false.
personalbar . visibleReturns true if the personal bar is visible; otherwise, returns false.
scrollbars . visibleReturns true if the scroll bars are visible; otherwise, returns false.
statusbar . visibleReturns true if the status bar is visible; otherwise, returns false.
toolbar . visibleReturns true if the toolbar is visible; otherwise, returns false.
The visible attribute's getter must run these steps:
If this BarProp object's relevant global object's browsing context is null, then return false.
If the user agent does not have a user interface element that the object represents, as described below, then return true.
Return true or a value determined by the user agent to most accurately represent the visibility state of the user interface element that the object represents, as described below.
The following BarProp objects must exist for each Window object:
BarProp objectBarProp objectBarProp objectBarProp objectBarProp objectvisible attribute may return false).BarProp objectvisible attribute may return
false).The locationbar attribute must return
the location bar BarProp object.
The menubar attribute must return the
menu bar BarProp object.
The personalbar attribute must return
the personal bar BarProp object.
The scrollbars attribute must return
the scrollbar BarProp object.
The statusbar attribute must return
the status bar BarProp object.
The toolbar attribute must return the
toolbar BarProp object.
For historical reasons, the status attribute
on the Window object must, on getting, return the last string it was set to, and on
setting, must set itself to the new value. When the Window object is created, the
attribute must be set to the empty string. It does not do anything else.
Window objectsWhen the user agent is required to set up a window environment settings object, given a JavaScript execution context execution context and an optional environment reserved environment, it must run the following steps:
Let realm be the value of execution context's Realm component.
Let window be realm's global object.
Let url be a copy of the URL of
window's associated
Document.
Let settings object be a new environment settings object whose algorithms are defined as follows:
Return execution context.
Return the module map of
window's associated
Document.
Return window's browsing context.
Return the event loop associated with window's relevant agent.
Return window's associated
Document.
Return the current character encoding
of window's associated
Document.
Return the current base URL of window's
associated Document.
Return the origin of window's associated Document.
Return the HTTPS state of
window's associated
Document.
Let document be window's associated Document.
While document is an iframe
srcdoc document and document's
referrer policy is the empty
string, set document to document's
browsing context's
browsing context container's node document.
Return document's referrer policy.
If reserved environment is given, then:
Set settings object's id to reserved environment's id, settings object's creation URL to reserved environment's creation URL, settings object's target browsing context to reserved environment's target browsing context, and settings object's active service worker to reserved environment's active service worker.
Set reserved environment's id to the empty string.
The identity of the reserved environment is considered to be fully transferred to the created environment settings object. The reserved environment is not searchable by the environment’s id from this point on.
Otherwise, set settings object's id to a new unique opaque string, settings object's creation URL to url, settings object's target browsing context to null, and settings object's active service worker to null.
Set realm's [[HostDefined]] field to settings object.
Return settings object.
WindowProxy exotic objectA WindowProxy is an exotic
object that wraps a Window ordinary object, indirecting most operations through to
the wrapped object. Each browsing context has an associated WindowProxy
object. When the browsing context is navigated, the
Window object wrapped by the browsing context's associated
WindowProxy object is changed.
The WindowProxy exotic object must use the ordinary internal methods except where
it is explicitly specified otherwise below.
There is no WindowProxy interface object.
Every WindowProxy object has a [[Window]] internal slot representing the wrapped Window
object.
Although WindowProxy is named as a "proxy", it does not do
polymorphic dispatch on its target's internal methods as a real proxy would, due to a desire to
reuse machinery between WindowProxy and Location objects. As long as the
Window object remains an ordinary object this is unobservable and can be implemented
either way.
Let W be the value of the [[Window]] internal slot of this.
If ! IsPlatformObjectSameOrigin(W) is true, then return ! OrdinaryGetPrototypeOf(W).
Return null.
Return ! SetImmutablePrototype(this, V).
Return true.
Return false.
Let W be the value of the [[Window]] internal slot of this.
If P is an array index property name, then:
Let index be ! ToUint32(P).
Let maxProperties be the number of document-tree child browsing contexts of W.
Let value be undefined.
If maxProperties is greater than 0 and index is less than
maxProperties, then set value to the WindowProxy object of
the indexth document-tree child browsing context of W's
browsing context, sorted in the order that their browsing context container elements were most
recently inserted into W's associated
Document, the WindowProxy object of the most recently inserted
browsing context container's nested browsing context being
last.
If value is undefined, then:
If ! IsPlatformObjectSameOrigin(W) is true, then return undefined.
Throw a "SecurityError" DOMException.
Return PropertyDescriptor{ [[Value]]: value, [[Writable]]: false, [[Enumerable]]: true, [[Configurable]]: true }.
If ! IsPlatformObjectSameOrigin(W) is true, then return ! OrdinaryGetOwnProperty(W, P).
This is a willful violation of the JavaScript specification's invariants of the essential internal methods to maintain compatibility with existing Web content. See tc39/ecma262 issue #672 for more information. [JAVASCRIPT]
Let property be ! CrossOriginGetOwnPropertyHelper(W, P).
If property is not undefined, then return property.
If property is undefined and P is in W's document-tree child browsing context name property set, then:
Let value be the WindowProxy object of the named object of W with the name
P.
Return PropertyDescriptor{ [[Value]]: value, [[Enumerable]]: false, [[Writable]]: false, [[Configurable]]: true }.
The reason the property descriptors are non-enumerable, despite this mismatching the same-origin behavior, is for compatibility with existing Web content. See issue #3183 for details.
Return ? CrossOriginPropertyFallback(P).
Let W be the value of the [[Window]] internal slot of this.
If ! IsPlatformObjectSameOrigin(W) is true, then:
If P is an array index property name, return false.
Return ? OrdinaryDefineOwnProperty(W, P, Desc).
This is a willful violation of the JavaScript specification's invariants of the essential internal methods to maintain compatibility with existing Web content. See tc39/ecma262 issue #672 for more information. [JAVASCRIPT]
Throw a "SecurityError" DOMException.
Let W be the value of the [[Window]] internal slot of this.
If ! IsPlatformObjectSameOrigin(W) is true, then return ? OrdinaryGet(this, P, Receiver).
Return ? CrossOriginGet(this, P, Receiver).
this is passed rather than W as OrdinaryGet and CrossOriginGet will invoke the [[GetOwnProperty]] internal method.
Let W be the value of the [[Window]] internal slot of this.
If ! IsPlatformObjectSameOrigin(W) is true, then return ? OrdinarySet(this, P, V, Receiver).
Return ? CrossOriginSet(this, P, V, Receiver).
this is passed rather than W as OrdinarySet and CrossOriginSet will invoke the [[GetOwnProperty]] internal method. OrdinarySet will also invoke the [[DefineOwnProperty]] internal method.
Let W be the value of the [[Window]] internal slot of this.
If ! IsPlatformObjectSameOrigin(W) is true, then:
If P is an array index property name, then:
Let desc be ! this.[[GetOwnProperty]](P).
If desc is undefined, then return true.
Return false.
Return ? OrdinaryDelete(W, P).
Throw a "SecurityError" DOMException.
Let W be the value of the [[Window]] internal slot of this.
Let keys be a new empty List.
Let maxProperties be the number of document-tree child browsing contexts of W.
Let index be 0.
Repeat while index < maxProperties,
Add ! ToString(index) as the last element of keys.
Increment index by 1.
If ! IsPlatformObjectSameOrigin(W) is true, then return the concatenation of keys and ! OrdinaryOwnPropertyKeys(W).
Return the concatenation of keys and ! CrossOriginOwnPropertyKeys(W).