title="Definition of 'parse a url' in HTML">defined in HTML</a>

[[!HTML]]

<dfn>list of descendant browsing contexts</dfn>,<ahref=

"https://html.spec.whatwg.org/multipage/browsers.html#list-of-the-descendant-browsing-contexts"

title=

"Definition of 'list of descendant browsing contexts' in HTML">defined

in HTML</a> [[!HTML]]

<dfn>creating a new browsing context</dfn>,<ahref=

"https://html.spec.whatwg.org/multipage/browsers.html#creating-a-new-browsing-context"

title="Definition of 'navigate to a fragment' in HTML">defined in

HTML</a> [[!HTML]]

<dfn>unload a document</dfn>,<ahref=

"https://html.spec.whatwg.org/multipage/document-lifecycle.html#unload-a-document"

title="Definition of 'unload a document' in HTML">defined in HTML</a>

[[!HTML]]

<dfn>database</dfn>,<ahref=

"https://www.w3.org/TR/IndexedDB/#database"title=

The<a>task source</a> for the tasks mentioned in this specification

is the<dfn>presentation task source</dfn>.

is the<var>presentation task source</var>.

Unless otherwise specified, the<a>JavaScript realm</a> for script

readonly attribute PresentationReceiver? receiver;

};

The<dfndata-dfn-for="Presentation"><code>receiver</code></dfn>

attribute MUST return the<a>PresentationReceiver</a> instance

context</a> is<adata-lt=

"create a receiving browsing context">created</a>. In any other

<a>browsing context</a> (including<adata-lt=

"nested browsing context">nested browsing contexts</a> of the

<a>receiving browsing context</a>) it MUST return

<code>null</code>.

"child navigable">child navigables</a> of the<a>receiving browsing

context</a>) it MUST return<code>null</code>.

<pclass="note">

Web developers can use<adata-lt=

<li>If the document's [=browsing context/active window=] does not

have[=transient activation=], return a {{Promise}} rejected with

an{{InvalidAccessError}} exception and abort these steps.

<li>If the document's [=navigable/active window=] does not have

[=transient activation=], return a {{Promise}} rejected with an

{{InvalidAccessError}} exception and abort these steps.

<li>Let<var>topContext</var> be the<a>top-level browsing

context</a> of the<a>controlling browsing context</a>.

<li>If there is already an unsettled {{Promise}} from a previous

call to<adata-link-for="PresentationRequest">start</a> in

<var>topContext</var> or any<a>browsing context</a> in the<a>list

ofdescendantbrowsing contexts</a> of<var>topContext</var>,

<var>topContext</var> or any<a>browsing context</a> in the

[=Document/descendantnavigables=] of<var>topContext</var>,

return a new {{Promise}} rejected with an {{OperationError}}

exception and abort all remaining steps.

When the<dfndata-dfn-for="PresentationRequest">reconnect</dfn>

method is called, the<a>user agent</a> MUST run the following

steps to<dfn>reconnect to a presentation</dfn>:

steps to reconnect to a presentation:

<a>Resolve</a><var>P</var> with<var>newConnection</var>.

<a>Queue a task</a> to [=fire an event=] named<adata-link-for=

<a>Queue a task</a> to [=fire an event=] named

<adata-link-for=

"PresentationRequest">connectionavailable</a>, that uses the

<a>PresentationConnectionAvailableEvent</a> interface, with

the<adata-link-for=

A<a>controlling user agent</a> [=fire an event|fires an event=]

named<adata-link-for="PresentationRequest">connectionavailable</a>

on a<a>PresentationRequest</a> when a connection associated with

the object is created. It is fired at the<a>PresentationRequest</a>

named<adata-link-for=

"PresentationRequest">connectionavailable</a> on a

<a>PresentationRequest</a> when a connection associated with the

object is created. It is fired at the<a>PresentationRequest</a>

instance, using the<a>PresentationConnectionAvailableEvent</a>

interface, with the<adata-link-for=

"PresentationConnectionAvailableEvent">connection</a> attribute set

<divclass="note">

A<adata-link-for="PresentationConnectionState">connected</a> state

does not mean that sending or receiving messages will succeed, as

the communication channel may be abruptly closed at any time.

Applications that wish to detect such situations as soon as possible

should implement their own keep-alive mechanism.

A<adata-link-for="PresentationConnectionState">connected</a>

statedoes not mean that sending or receiving messages will

succeed, asthe communication channel may be abruptly closed at any

time.Applications that wish to detect such situations as soon as

possibleshould implement their own keep-alive mechanism.

When the<dfn>close</dfn> method is called on a

attribute initialized to<var>closeReason</var> and the

<adata-link-for="PresentationConnectionCloseEvent">message</a>

attribute initialized to<var>closeMessage</var>, at

<var>presentationConnection</var>. The event must not bubble and

must not be cancelable.

<var>presentationConnection</var>. The event must not bubble

andmust not be cancelable.

<var>known connection</var> to<adata-link-for=

"PresentationConnectionState">terminated</a>.

<li>[=Fire an event=] named<code>terminate</code> at

<var>known connection</var>.

<li>[=Fire an event=] named<code>terminate</code> at<var>

known connection</var>.

<li>If there is a<a>receiving browsing context</a> for

<var>P</var>, and it has a document for<var>P</var> that is not

unloaded,<a>unload a document</a> corresponding to that

<a>browsingcontext</a>, remove that<a>browsing context</a> from

the userinterface and<a>discard</a> it.

unloaded,<a>unload a document</a> corresponding to that<a>browsing

context</a>, remove that<a>browsing context</a> from the user

interface and discard it.

<li>For each<var>connection</var> in

<var>connectedControllers</var>,<a>queue a task</a> to send a

Handling a termination confirmation in a controlling user agent

When a<a>receiving user agent</a> is to<dfn>send a termination

confirmation</dfn> for a presentation<var>P</var>, and that

confirmationwas received by a<a>controlling user agent</a>, the

<a>controllinguser agent</a> MUST run the following steps:

When a<a>receiving user agent</a> is to send a termination

confirmation for a presentation<var>P</var>, and that confirmation

was received by a<a>controlling user agent</a>, the<a>controlling

user agent</a> MUST run the following steps:

<li>For each<var>connection</var> in the<a>set of controlled

auxiliary navigation browsing context flag</a> on<var>C</var>.

<li>If the<a>receiving user agent</a> implements [[!PERMISSIONS]],

set the<a>permission state</a> of all [=powerful feature/permission

descriptor types=] for<var>C</var> to<code>"denied"</code>.

set the<a>permission state</a> of all [=powerful

feature/permission descriptor types=] for<var>C</var> to

<code>"denied"</code>.

<li>Create a new empty<a>cookie store</a> for<var>C</var>.

All<adata-lt="nested browsing context">nested browsing

contexts</a><adata-lt=

All<adata-lt="child navigable">child navigables</a><adata-lt=

"creating a new browsing context">created</a> by the presented

document, i.e. that have the<a>receiving browsing context</a> as

their<adata-lt="top-level browsing context">top-level browsing

[=service worker client/window client|Window clients=] and

[=service worker client/worker client|worker clients=] associated

with the<a>receiving browsing context</a> and its<a>list of

descendantbrowsing contexts</a> must not be exposed to<a>service

with the<a>receiving browsing context</a> and its

[=Document/descendantnavigables=] must not be exposed to<a>service

workers</a> associated with each other.

When the<a>receiving browsing context</a> is terminated, any

<a>service workers</a> associated with it and the<a>browsing

contexts</a> in its<a>list ofdescendantbrowsing contexts</a>

contexts</a> in its[=Document/descendantnavigables=]

MUST be unregistered and terminated. Any browsing state associated

with the<a>receiving browsing context</a> and the<a>browsing

contexts</a> in its<a>list ofdescendantbrowsing contexts</a>,

contexts</a> in its[=Document/descendantnavigables=],

including<a>session history</a>, the<a>cookie store</a>, any

<a>HTTP authentication</a> state, any<a>databases</a>, the

<a>session storage areas</a>, the<a>local storage areas</a>, the

Display of the origin requesting presentation will help the user

understand what content is making the request, especially when

the request is initiated from a<a>nested browsing context</a>.

Forexample, embedded content may try to convince the user to

clickto trigger a request to start an unwanted presentation.

the request is initiated from a<a>child navigable</a>. For

example, embedded content may try to convince the user to click

to trigger a request to start an unwanted presentation.

The<a>sandboxed top-level navigation without user activation