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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>
Web App Manifest
</title>
<script src="https://www.w3.org/Tools/respec/respec-w3c" class=
"remove"></script>
<script class='remove'>
var respecConfig = {
mdn: true,
previousPublishDate: "2013-12-17",
specStatus: "ED",
shortName: "appmanifest",
prevVersion: "FPWD",
previousMaturity: "WD",
formerEditors: [
{
name: "Rob Dolin",
company: "Microsoft Corporation",
companyURL: "https://www.microsoft.com/en-us/",
},
],
editors: [
{
name: "Marcos Cáceres",
company: "Mozilla Corporation",
companyURL: "https://mozilla.org/",
w3cid: 39125,
},
{
name: "Kenneth Rohde Christiansen",
company: "Intel Corporation",
companyURL: "https://intel.com/",
w3cid: 57705,
},
{
name: "Mounir Lamouri",
company: "Google Inc.",
companyURL: "https://www.google.com/",
w3cid: 45389,
},
{
name: "Anssi Kostiainen",
company: "Intel Corporation",
companyURL: "https://intel.com/",
w3cid: 41974,
},
{
name: "Matt Giuca",
company: "Google Inc.",
companyURL: "https://www.google.com/",
w3cid: 91260,
},
{
name: "Aaron Gustafson",
company: "Microsoft Corporation",
companyURL: "https://microsoft.com/",
w3cid: 43672,
},
],
group: "webapps",
github: "https://github.com/w3c/manifest/",
caniuse: {
feature: "web-app-manifest",
browsers: [
"chrome",
"firefox",
"safari",
"edge",
"and_chr",
"and_ff",
"ios_saf",
],
},
xref: "web-platform",
};
</script>
<style>
.icon-title {
text-transform: uppercase;
font-weight: bold;
}
.icons {
display: flex;
flex-direction: row;
flex-wrap: wrap;
}
.icons > figure {
text-align: left;
margin: 0;
padding: 10px;
width: 188px;
}
.icons > figure > img {
width: 188px;
height: 188px;
min-width: 188px;
min-height: 188px;
}
.icons > figure .icon-title {
display: block;
}
</style>
</head>
<body data-cite="ENCODING SCREEN-ORIENTATION MEDIAQUERIES-5">
<section id='abstract'>
<p>
This specification defines a JSON-based file format that provides
developers with a centralized place to put metadata associated with a
web application. This metadata includes, but is not limited to, the web
application's name, links to icons, as well as the preferred URL to
open when a user launches the web application. The manifest also allows
developers to declare a default screen orientation for their web
application, as well as providing the ability to set the display mode
for the application (e.g., in fullscreen). Additionally, the manifest
allows a developer to "scope" a web application to a URL. This
restricts the URLs to which the manifest is applied and provides a
means to "deep link" into a web application from other applications.
</p>
<p>
Using this metadata, user agents can provide developers with means to
create user experiences that are more comparable to that of a native
application.
</p>
<p>
This specification also defines the `manifest` link type as a
declarative means to associate a document with a manifest.
</p>
</section>
<section id="sotd">
<div class="warning">
<p>
Implementors need to be aware that this specification is not stable.
However, aspects of this specification are shipping in at least one
browser (see links to implementation status at the top of this
document). <strong>Implementors who are not taking part in the
discussions will find the specification changing out from under them
in incompatible ways.</strong> Vendors interested in implementing
this specification before it eventually reaches the Candidate
Recommendation phase should <a href=
"https://github.com/w3c/manifest/issues">subscribe to the repository
on GitHub</a> and take part in the discussions.
</p>
</div>
</section>
<section class="informative">
<h2>
Usage Examples
</h2>
<p>
This section shows how developers can make use of the various features
of this specification.
</p>
<section class="informative">
<h3>
Example manifests
</h3>
<p>
The following shows a very simple <a>manifest</a>.
</p>
<pre class="example json" title="very simple manifest">
{
"name": "Donate App",
"description": "This app helps you donate to worthy causes.",
"icons": [{
"src": "images/icon.png",
"sizes": "192x192"
}]
}
</pre>
<p>
The following shows a more typical <a>manifest</a>.
</p>
<pre class="example json" title="typical manifest">
{
"lang": "en",
"dir": "ltr",
"name": "Super Racer 3000",
"description": "The ultimate futuristic racing game from the future!",
"short_name": "Racer3K",
"icons": [{
"src": "icon/lowres.webp",
"sizes": "64x64",
"type": "image/webp"
},{
"src": "icon/lowres.png",
"sizes": "64x64"
}, {
"src": "icon/hd_hi",
"sizes": "128x128"
}],
"scope": "/racer/",
"start_url": "/racer/start.html",
"display": "fullscreen",
"orientation": "landscape",
"theme_color": "aliceblue",
"background_color": "red",
"screenshots": [{
"src": "screenshots/in-game-1x.jpg",
"sizes": "640x480",
"type": "image/jpeg"
},{
"src": "screenshots/in-game-2x.jpg",
"sizes": "1280x920",
"type": "image/jpeg"
}]
}
</pre>
</section>
<section class="informative">
<h3>
Using a `link` element to link to a manifest
</h3>
<p>
Example of using a [^link^] element to associate a website with a
<a>manifest</a>. The example also shows how to use [[HTML]]'s
[^link^] and <a data-tl="meta element">`meta`</a> elements to give
the web application a fallback name and set of icons.
</p>
<pre class="example html" title="linking to a manifest">
<!doctype>
<html>
<title>Racer 3K</title>
<!-- Startup configuration -->
<link rel="manifest" href="manifest.webmanifest">
<!-- Fallback application metadata for legacy browsers -->
<meta name="application-name" content="Racer3K">
<link rel="icon" sizes="16x16 32x32 48x48" href="lo_def.ico">
<link rel="icon" sizes="512x512" href="hi_def.png">
</pre>
<div class="note" title="manifest.webmanifest or manifest.json?">
The official file extension for the manifest is `.webmanifest`. Some
web servers recognize this extension and transfer the file using the
standardized <a>application manifest MIME type</a>
(`application/manifest+json`). Developers can also choose a different
extension (e.g. `.json`) or none at all (e.g. `/api/GetManifest`),
but are strongly encouraged to transfer the manifest using the
`application/manifest+json` <a data-cite="mimesniff">MIME type</a>.
</div>
</section>
</section>
<section>
<h2>
Installable web applications
</h2>
<p>
A common use case of a manifest is for a user agent to
<dfn data-local-lt="installing|installation" data-lt=
"installed">install</dfn> a web application; whereby the user agent
provides the end-user with a means of instantiating a new <a>top-level
browsing context</a> that has the manifest's members <a>applied</a> to
it. A web application that is installed is known as a <dfn data-export=
"">installed web application</dfn>. That is, the manifest's members, or
their defaults, are in effect on the <a>top-level browsing context</a>.
This distinguishes an installed web application from a traditional
bookmark, as opening a web page from a traditional bookmark will not
have the manifest's properties <a>applied</a> to it.
</p>
<p>
For example, on user agents that support installation, a web
application could be presented and launched in a way that, to the
end-user, is indistinguishable from native applications: such as
appearing as a labeled icon on the home screen, launcher, or start
menu. When launched, the manifest is <a>applied</a> by the user agent
to the <a>top-level browsing context</a> prior to the <a>start URL</a>
being loaded. This gives the user agent an opportunity to apply the
relevant values of the manifest, possibly changing the <a>display
mode</a> and screen orientation of the web application. Alternatively,
and again as an example, the user agent could <a>install</a> the web
application into a list of bookmarks within the user agent itself.
</p>
<p>
A [=document=] may either be <dfn>installable</dfn> or not. The initial
state of a document is not <a>installable</a>.
</p>
<p>
At any time, the user agent MAY perform the <dfn>steps to determine
installability of the document</dfn>:
</p>
<ol>
<li>Let <var>manifest</var> and <var>manifest URL</var> be the result
of <a>obtaining the manifest</a>.
</li>
<li>If <a>obtaining the manifest</a> results in an error, the user
agent MAY either:
<ul>
<li>Fall back to using the <a>top-level browsing context</a>
{{Document}}'s metadata to populate <var>manifest</var> in a
user-agent-specific way (e.g., setting
|manifest|.{{WebAppManifest/name}} to the document [^title^] and
considering the document <a>installable</a>.
</li>
<li>Or, consider the document not <a>installable</a>.
</li>
</ul>
</li>
<li>Otherwise, at its discretion, the user agent MAY consider the
{{Document}} <a>installable</a> (see [[[#installability-signals]]]).
</li>
</ol>
<section>
<h3>
Authority of the manifest's metadata
</h3>
<p>
When a <a>manifest</a> is linked from a {{Document}}, it indicates to
the user agent that the metadata is <dfn>authoritative</dfn>: that
is, the user agent SHOULD use the metadata of the manifest instead of
the one in the {{Document}}. However, in cases where metadata is
missing, or in error, a user agent MAY fallback to the {{Document}}
to find suitable replacements for missing manifest members (e.g.,
using `application-name` in place of `short_name`).
</p>
</section>
<section data-link-for="WebAppManifest">
<h3>
Application's name
</h3>
<p>
The <dfn>application's name</dfn> is derived from either the
<a>name</a> member or <a>short_name</a> member (if either is present)
- otherwise, it is generated by the user agent or provided by the
end-user.
</p>
<p>
When either member is missing from the manifest, a user agent MAY use
the <a>name</a> member as a fallback for the <a>short_name</a> member
or vice versa.
</p>
<p>
If the <a>name</a> and <a>short_name</a> members are undefined, the
user agent SHOULD assign a default name (e.g., "Untitled") that
follows platform conventions. Alternatively, a user agent MAY allow
the end-user to input some text that can serve as the
<a>application's name</a>.
</p>
<p>
When both the <a>name</a> and <a>short_name</a> members are present,
it is left up to implementations to decide which member is best
suited for the space available (e.g., the <a>short_name</a> member
might be better suited for the space available underneath an icon).
</p>
</section>
<section>
<h3 id="installation-sec">
Privacy and security considerations
</h3>
<p>
It is RECOMMENDED that UI that affords the end user the ability to
<a>install</a> a web application also allows inspecting the icon,
name, <a>start URL</a>, origin, etc. pertaining to a web application.
This is to give an end-user an opportunity to make a conscious
decision to approve, and possibly modify, the information pertaining
to the web application before installing it. This also gives the
end-user an opportunity to discern if the web application is spoofing
another web application, by, for example, using an unexpected icon or
name.
</p>
<p>
It is RECOMMENDED that user agents prevent other applications from
determining which applications are installed on the system (e.g., via
a timing attack on the user agent's cache). This could be done by,
for example, invalidating from the user agent's cache the resources
linked to from the manifest (for example, icons) after a web
application is <a>installed</a> - or by using an entirely different
cache from that used for regular web browsing.
</p>
</section>
<section class="informative">
<h3 id="installability-signals">
Installability signals
</h3>
<p>
By design, this specification does not provide developers with an
explicit API to "install" a web application. Instead, a
<a>manifest</a> can serve as an <dfn>installability signal</dfn> to a
user agent that a web application can be <a>installed</a>.
</p>
<p>
Examples of <a>installability signals</a> for a web application:
</p>
<ul>
<li>is <a>associated with a manifest</a> with at least a
<code>name</code> member and a suitable icon.
</li>
<li>is served over a secure network connection.
</li>
<li>has a sensible content security policy.
</li>
<li>is able to responsively adapt to display on a variety of screen
sizes, catering for both mobile and desktop.
</li>
<li>is able to function without a network connection.
</li>
<li>is repeatedly used by the end-user over some extended period of
time.
</li>
<li>has been explicitly marked by the user as one that they value and
trust (e.g., by bookmarking or "starring" it).
</li>
</ul>
<p>
This list is not exhaustive and some <a>installability signals</a>
might not apply to all user agents. How a user agent makes use of
these <a>installability signals</a> to determine if a web application
can be <a>installed</a> is left to implementers.
</p>
</section>
<section>
<h3>
Uninstallation
</h3>
<p>
User agents SHOULD provide a mechanism for the user to remove an
<a>installed web application</a> application.
</p>
<p>
It is RECOMMENDED that at the time of removal, the user agent also
present the user with an opportunity to revoke other persistent data
and settings associated with the application, such as permissions and
persistent storage.
</p>
</section>
</section>
<section>
<h2>
Navigation scope
</h2>
<p data-link-for="WebAppManifest">
The <dfn data-dfn-for="manifest" data-lt="navigation scope"
data-export="">navigation scope of a manifest</dfn> is the
{{WebAppManifest/scope}} member of a [=processed manifest=]. The
navigation scope restricts the set of URLs to which an [=application
context=] can be [=navigated=] while the manifest is [=applied=].
</p>
<div class="note" data-link-for="WebAppManifest">
<p>
If the <a>scope</a> member is not present in the manifest, it
defaults to the parent path of the <a>start_url</a> member. For
example, if <a>start_url</a> is <code>/pages/welcome.html</code>, and
<a>scope</a> is missing, the navigation scope will be
<code>/pages/</code> on the same origin. If <a>start_url</a> is
<code>/pages/</code> (the trailing slash is important!), the
navigation scope will be <code>/pages/</code>.
</p>
<p>
Developers should take care, if they rely on the default behavior,
that all of the application's page URLs begin with the parent path of
the start URL. To be safe, explicitly specify <a>scope</a>.
</p>
</div>
<p>
A [=URL=] |target:URL| is said to be <dfn data-dfn-for="URL"
data-export="">within scope</dfn> of [=URL=] |scope:URL| if the
following algorithm returns `true`:
</p>
<ol class="algorithm">
<li>If |target| and |scope| are not [=same origin=], return `false`.
</li>
<li>Let |scopePath:string| be the [=string/concatenation=] of
|scopes|'s [=URL/path=] using U+002F (/) as the separator.
</li>
<li>Let |targetPath:string| be the [=string/concatenation=] of
|target|'s [=URL/path=] using U+002F (/) as the separator.
</li>
<li>Return a [=boolean=] indicating whether |targetPath| starts with
|scopePath:string|.
</li>
</ol>
<p>
A [=URL=] |target:URL| is <dfn data-dfn-for="manifest" data-lt=
"within scope" data-export="">within scope</dfn> of a
|manifest:processed manifest| if the |target| is [=URL/within scope=]
of |manifest|'s [=manifest/navigation scope=] (i.e., [=URL/within
scope=] of |manifest|'s {{WebAppManifest/scope}} member).
</p>
<div class="note" title="Scope is a simple string match">
The URL string matching in this algorithm is prefix-based rather than
path-structural (e.g. a target URL string
<code>/prefix-of/resource.html</code> will match an app with scope
<code>/prefix</code>, even though the path segment name is not an exact
match). This is intentional for consistency with <a data-cite=
"SERVICE-WORKERS-1#scope-match-algorithm">Service Workers</a>. To avoid
unexpected behavior, use a scope ending in a <code>/</code>.
</div>
<p>
If the [=application context=]'s [=active document=]'s [=Document/URL=]
is not [=manifest/within scope=] of the [=application context=]'s
[=processed manifest=], the user agent SHOULD show a prominent UI
element indicating the [=Document/URL=] or at least its [=origin=],
including whether it is served over a secure connection. This UI SHOULD
differ from any UI used when the [=Document/URL=] is [=manifest/within
scope=] of the [=application context=]'s [=processed manifest=], in
order to make it obvious that the user is navigating off scope.
</p>
<div class="note">
<p>
Nothing prevents an <a>application context</a> from navigating to a
<a>URL</a> that is outside of the manifest's [=manifest/navigation
scope=], while still having the <a>manifest</a> <a>applied</a> to it.
</p>
<p>
Unlike previous versions of this specification, user agents are no
longer required or allowed to block off-scope navigations, or open
them in a new <a>top-level browsing context</a>. This practice broke
some sites that navigate to an off-scope URL (e.g., to perform
third-party authentication). See <a href=
"https://github.com/w3c/manifest/issues/646">Issue 646</a>.
</p>
</div>
<section data-link-for="DisplayModeType" class="informative">
<h3 id="navigation-scope-security-considerations">
Security considerations
</h3>
<p>
The above recommendation (to show some UI when the <a>application
context</a> is navigated to an out-of-scope <a>URL</a>) is for
security reasons. It ensures that users are always aware of which
<a>origin</a> they are interacting with.
</p>
<p>
Despite this, there is still a potential spoofing risk, if an
installed app pretends to navigate to an out-of-scope site on another
<a>origin</a>. The site shows a fake version of the user agent's
prominent out-of-scope UI, indicating to the user that it is on
another origin. However, in reality, the user has never navigated
away from the installed app's origin, and the user agent is not
showing any out-of-scope UI. User agents could try to show the
out-of-scope UI in a way that cannot be spoofed by the installed app.
However, due to the nature of the user agent's UI being minimal or
non-existent for installed apps, this may not be possible.
</p>
</section>
<section>
<h3>
Deep links
</h3>
<p>
A <dfn>deep link</dfn> is a URL that is [=manifest/within scope=] of
an [=installed web application=]'s [=processed manifest=].
</p>
<p>
An <a>application context</a> can be instantiated through a <a>deep
link</a>, in which case, the manifest is applied and the <a>deep
link</a> is loaded within the context of a web application.
</p>
<div class="note">
<p>
The concept of a <a>deep link</a> is useful in that it allows
hyperlinking from one <a>installed web application</a> to another.
This can be from a native application to an <a>installed web
application</a> (and possibly vice versa!). Theoretically, this can
provide seamless context switching between native and web
applications through standard hyperlinks. And in the case where a
particular web application is not <a>installed</a>, the OS can just
open the link in the user's preferred web browser.
</p>
<p>
Implementers are encouraged make such context switching obvious to
the user, for example, by adhering to the human interface
guidelines of the underlying platform with respect to application
switching.
</p>
</div>
</section>
</section>
<section data-dfn-for="DisplayModeType" data-link-for="DisplayModeType">
<h2>
Display modes
</h2>
<p>
A <dfn>display mode</dfn> represents how the web application is being
presented within the context of an OS (e.g., in fullscreen, etc.).
Display modes correspond to user interface (UI) metaphors and
functionality in use on a given platform. The UI conventions of the
display modes are purely advisory and implementers are free to
interpret them how they best see fit.
</p>
<p>
Once a user agent applies a particular <a>display mode</a> to an
<a>application context</a>, it becomes the <dfn>default display
mode</dfn> for the <a>top-level browsing context</a> (i.e., it is used
as the display mode when the window is <a>navigated</a>). The user
agent MAY override the <a>default display mode</a> for security reasons
(e.g., the <a>top-level browsing context</a> is <a>navigated</a> to
another origin) and/or the user agent MAY provide the user with a means
of switching to another <a>display mode</a>.
</p>
<p>
When the <a data-link-for="WebAppManifest">display</a> member is
missing, or if there is no valid <a data-link-for=
"WebAppManifest">display</a> member, the user agent uses the
<a>browser</a> <a>display mode</a> as the <a>default display mode</a>.
As such, the user agent MUST support the <a>browser</a> <a>display
mode</a>.
</p>
<p>
Each <a>display mode</a>, except <code>browser</code>, has a
<dfn>fallback display mode</dfn>, which is the <a>display mode</a> that
the user agent can try to use if it doesn't support a particular
<a>display mode</a>. If the user agent does support a <a>fallback
display mode</a>, then it checks to see if it can use that <a>display
mode</a>'s <a>fallback display mode</a>. This creates a fallback chain,
with the <a>default display mode</a> (<code>browser</code>) being the
last item in the chain.
</p>
<div class="example">
<p>
For example, SuperSecure Browser (a fictitious browser) only supports
the <code>minimal-ui</code> and <code>browser</code> display modes,
but a developer declares that she wants <code>fullscreen</code> in
the manifest. In this case, the user agent will first check if it
supports <code>fullscreen</code> (it doesn't), so it falls back to
<code>standalone</code> (which it also doesn't support), and
ultimately falls back to <code>minimal-ui</code>.
</p>
</div>
<p>
The <dfn>display modes values</dfn> defined by
<dfn>DisplayModeType</dfn>, and their corresponding <a>fallback display
modes</a> are as follows:
</p>
<dl>
<dt>
<dfn>fullscreen</dfn>
</dt>
<dd>
Opens the web application without any user agent chrome and takes up
the entirety of the available display area.
</dd>
<dd>
The <a>fallback display mode</a> for <code>fullscreen</code> is
<code>standalone</code>.
</dd>
<dt>
<dfn>standalone</dfn>
</dt>
<dd>
Opens the web application to look and feel like a standalone native
application. This can include the application having a different
window, its own icon in the application launcher, etc. In this mode,
the user agent will exclude standard browser UI elements such as an
URL bar, but can include other system UI elements such as a status
bar and/or system back button.
</dd>
<dd>
The <a>fallback display mode</a> for <code>standalone</code> is
<code>minimal-ui</code>.
</dd>
<dt>
<dfn>minimal-ui</dfn>
</dt>
<dd>
This mode is similar to <a>standalone</a>, but provides the end-user
with some means to access a minimal set of UI elements for
controlling navigation (i.e., back, forward, reload, and perhaps some
way of viewing the document's address). A user agent can include
other platform specific UI elements, such as "share" and "print"
buttons or whatever is customary on the platform and user agent.
</dd>
<dd>
The <a>fallback display mode</a> for <code>minimal-ui</code> is
<code>browser</code>.
</dd>
<dt>
<dfn>browser</dfn>
</dt>
<dd>
Opens the web application using the platform-specific convention for
opening hyperlinks in the user agent (e.g., in a browser tab or a new
window).
</dd>
<dd>
The <code>browser</code> <a>display mode</a> doesn't have a
<a>fallback display mode</a> (conforming user agents are required to
support the <code>browser</code> <a>display mode</a>).
</dd>
</dl>
<p class="note">
The <a>fullscreen</a> <a>display mode</a> is orthogonal to, and works
independently of, the [[[FULLSCREEN]]]. The <a>fullscreen</a>
<a>display mode</a> affects the fullscreen state of the browser window,
while the [[FULLSCREEN]] API operates on an element contained within
the viewport. As such, a web application can have its <a>display
mode</a> set to <a>fullscreen</a>, while
<code>document.fullScreenElement</code> returns <code>null</code>, and
<code>fullscreenEnabled</code> returns <code>false</code>.
</p>
<section>
<h3>
Privacy and security considerations
</h3>
<p>
When the web application is running, it is RECOMMENDED that the user
agent provides the end-user a means to access common information
about the web application, such as the origin, start and/or current
URL, granted permissions, and associated icon. How such information
is exposed to end-users is left up to implementers.
</p>
<p>
Additionally, when applying a manifest that sets the <a>display
mode</a> to anything except "<a>browser</a>", it is RECOMMENDED that
the user agent clearly indicate to the end-user that their are
leaving the normal browsing context of a web browser. Ideally,
launching or switching to a web application is performed in a manner
that is consistent with launching or switching to other applications
in the host platform. For example, a long and obvious animated
transition, or speaking the text "Launching application X".
</p>
</section>
<section data-link-for="DisplayModeType">
<h3>
The <code>'display-mode'</code> media feature
</h3>
<p>
The <code><dfn>display-mode</dfn></code> media feature represents,
via a CSS media query [[MEDIAQ]], the <a>display mode</a> of the web
application. This media feature applies to the top-level browsing
context and any child browsing contexts. Child browsing contexts
reflect the <a>display mode</a> of the <a>top-level browsing
context</a>.
</p>
<p>
A user agent MUST expose the '<code>display-mode</code>' media
feature irrespective of whether a manifest is being applied to a
browsing context. For example, if the end-user puts the whole user
agent into fullscreen, then the user agent would reflect this change
to CSS and scripts via the '<code>display-mode</code>' media feature.
</p>
<div class="note">
<p>
Please note that the <code>fullscreen</code> <a>display mode</a> is
not directly related to the CSS <code>:fullscreen</code>
pseudo-class specified in the [[[FULLSCREEN]]]. The
<code>:fullscreen</code> pseudo-class matches exclusively when a
[[HTML]] element is put into the fullscreen element stack. However,
a side effect of calling the <code>requestFullscreen()</code>
method on an element using the [[FULLSCREEN]] API is that the
browser window can enter a fullscreen mode at the OS-level. In such
a case, both <code>:fullscreen</code> and <code>(display-mode:
fullscreen)</code> will match.
</p>
<p>
On some platforms, it is possible for a user to put a browser
window into fullscreen without the aid of the [[[FULLSCREEN]]].
When this happens, the <code>:fullscreen</code> pseudo class will
not match, but <code>(display-mode: fullscreen)</code> will match.
This is exemplified in CSS code below.
</p>
<pre class='example'>
/* applies when the window is fullscreen */
@media all and (display-mode: fullscreen) {
...
}
/* applies when an element goes fullscreen */
#game:fullscreen {
...
}
</pre>
</div>
<dl>
<dt>
Value:
</dt>
<dd>
<a>fullscreen</a> | <a>standalone</a> | <a>minimal-ui</a> |
<a>browser</a>
</dd>
<dt>
Applies to:
</dt>
<dd>
visual media types
</dd>
<dt>
Accepts min/max prefixes:
</dt>
<dd>
No
</dd>
</dl>
<p>
A user agent MUST reflect the applied <a>display mode</a> of the web
application via a CSS media query [[MEDIAQ]].
</p>
<section>
<h4>
Examples
</h4>
<p>
An example in CSS:
</p>
<pre class="example js">
@media all and (display-mode: minimal-ui) {
/* ... */
}
@media all and (display-mode: standalone) {
/* ... */
}
</pre>
<p>
Accessing the display-mode media feature in ECMAScript through
<code>matchMedia()</code> of [[CSSOM-VIEW]]:
</p>
<pre class="example">
const standalone = matchMedia( '(display-mode: standalone)' );
standalone.onchange = (e) => {
/* handle changes to display mode */
}
if (standalone.matches) {
/* do standalone things */
}
</pre>
</section>
<section>
<h3>
Security and privacy considerations
</h3>
<p>
The <code>'display-mode'</code> media feature allows an origin
access to aspects of a user’s local computing environment and,
together with the <code>display</code> member, allows an origin
some measure of control over a user agent’s native UI: Through a
CSS media query, a script can know the display mode of a web
application. An attacker could, in such a case, exploit the fact
that an application is being displayed in fullscreen to mimic the
user interface of another application.
</p>
</section>
</section>
</section>
<section>
<h3>
Associating a resource with a manifest
</h3>
<p>
A resource is said to be <dfn>associated with a manifest</dfn> if the
resource representation, an HTML document, has a <a href=
"#linking"><code>manifest</code> link relationship</a>.
</p>
<section id="linking">
<h3>
Linking to a manifest
</h3>
<p>
The <code>manifest</code> keyword can be used with a [[HTML]]
[^link^] element. This keyword creates an <a>external resource
link</a>.
</p>
<table class="complex data">
<thead>
<tr>
<th rowspan="2">
Link type
</th>
<th colspan="2">
Effect on...
</th>
<th rowspan="2">
Brief description
</th>
</tr>
<tr>
<th>
<code><a>link</a></code>
</th>
<th>
<code><a>a</a></code> and <code><a>area</a></code>
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code>manifest</code>
</td>
<td>
<a>External Resource Link</a>
</td>
<td>
not allowed
</td>
<td>
Imports or links to a <a>manifest</a>.
</td>
</tr>
</tbody>
</table>
<p>
The <a>application manifest MIME type</a> serves as the default
<a data-cite="mimesniff">MIME type</a> for resources associated with
the "<code>manifest</code>" link type.
</p>
<p class="note">
In cases where more than one [^link^] element with a
<code>manifest</code> link type appears in a {{Document}}, the user
agent uses the first [^link^] element in tree order and ignores all
subsequent [^link^] elements with a <code>manifest</code> link type
(even if the first element was erroneous). See the steps for
<a>obtaining a manifest</a>.
</p>
<p>
To obtain a manifest, the user agent MUST run the steps for
<a data-lt="obtaining the manifest">obtaining a manifest</a>. The
appropriate time to obtain the manifest is left up to
implementations. A user agent MAY opt to delay fetching a manifest
until after the document and its other resources have been fully
loaded (i.e., to not delay the availability of content and scripts
required by the <a data-cite="DOM">document</a>).
</p>
<p>
A <a>manifest</a> is obtained and applied regardless of the
{{HTMLLinkElement/media}} attribute of the [^link^] element matches
the environment or not.
</p>
</section>
</section>
<section>
<h2>
Manifest life-cycle
</h2>
<p>
This section defines algorithms for <a href="#obtaining">obtaining</a>,
<a href="#processing">processing</a>, and <a>applying</a> a
<a>manifest</a>.
</p>
<section id="obtaining">
<h3>
Obtaining a manifest
</h3>
<p>
The <dfn data-lt="obtaining the manifest|obtaining a manifest">steps
for obtaining a manifest</dfn> are given by the following algorithm.
The algorithm, if successful, returns a <a>processed manifest</a> and
the <var>manifest URL</var>; otherwise, it aborts prematurely and
returns nothing. In the case of nothing being returned, the user
agent MUST ignore the manifest declaration. In running these steps, a
user agent MUST NOT <a>delay the load event</a>.
</p>
<ol>
<li>From the {{Document}} of the <a>top-level browsing context</a>,
let <var>origin</var> be the {{Document}}'s origin, and <var>manifest
link</var> be the first [^link^] element in <a>tree order</a> whose
{{HTMLLinkElement/rel}} attribute contains the token
<code>manifest</code>.
</li>
<li>If <var>origin</var> is an <a>opaque origin</a>, then abort these
steps.
</li>
<li>If <var>manifest link</var> is <code>null</code>, then abort
these steps.
</li>
<li>If <var>manifest link</var>'s <code>href</code> attribute's value
is the empty <a>string</a>, then abort these steps.
</li>
<li>Let <var>manifest URL</var> be the result of [=URL
Parser|parsing=] the value of the <code>href</code> attribute,
relative to the [=document base URL=]. If parsing fails, then abort
these steps.
</li>
<li>Let |request:Request| be a new <a>Request</a>.
</li>
<li>Set |request|'s [=request/URL=] to |manifest URL|.
</li>
<li>Set |request|'s [=request/initiator=] to "`manifest`".
</li>
<li>Set |request|'s [=request/destination=] to "`manifest`".
</li>
<li>If the |manifest link|'s {{HTMLLinkElement/crossOrigin}}
attribute's value is "`use-credentials`", then set |request|'s
[=request/credentials mode=] to "`include`". Otherwise, set
|request|'s [=request/credentials mode=] to "`omit`".
</li>
<li>Set |request|'s [=request/mode=] to "`cors`".
</li>
<li>Await the result of performing a <a>fetch</a> with
<var>request</var>, letting <var>response</var> be the result.
</li>
<li>If <var>response</var> is a <a>network error</a>, then abort
these steps.
</li>
<li>Let <var>text</var> be <a>UTF-8 decode</a> <var>response</var>'s
<a data-cite="FETCH#concept-request-body">body</a>.
</li>
<li>Let <var>manifest</var> be the result of running <a>processing a
manifest</a> given <var>text</var>, <var>manifest URL</var>, and the
URL that represents the address of the <a>top-level browsing
context</a>.
</li>