fuchsia.web

PROTOCOLS

Context

Defined in fuchsia.web/context.fidl

Manages browsing state (e.g. LocalStorage, cookies, etc) associated with a set of Frame.

CreateFrame

Creates a new Frame under this Context. Destruction of a Context triggers the destruction of all of its associated Frame. Frame can be transferred to another component but cannot be shared across multiple components.

• frame: An interface request that will be bound to the created Frame.

Request

Name	Type
frame	request<Frame>

CreateFrameWithParams

Similar to Context.CreateFrame, with extra parameters.

• params: The configuration used to create the Frame. This method will fail with ZX_ERR_INVALID_ARGS if the table is not clonable.
• frame: An interface request that will be bound to the created Frame.

Request

Name	Type
params	CreateFrameParams
frame	request<Frame>

GetCookieManager

Used to observe cookies for sites hosted under this Context.

Request

Name	Type
manager	request<CookieManager>

GetRemoteDebuggingPort

Waits until debugging is available on one or more Frames, and returns the DevTools port number. Multiple calls may be queued to received the port number.

If an error occured, the ContextError will be set to this value:

• REMOTE_DEBUGGING_PORT_NOT_OPENED: remote_debugging_port was not set in CreateContextParams or the remote debugging service failed to start.

Request

Name	Type

Response

Name	Type
result	Context_GetRemoteDebuggingPort_Result

ContextProvider

Defined in fuchsia.web/context.fidl

The top-level service interface which allows for the creation of Context resources.

Create

Creates a new browser Context whose state is wholly independent and isolated from other Context(Contexts).

• params: The configuration used to create the Context.
• context: An interface request which will receive a bound Context service.

Request

Name	Type
params	CreateContextParams
context	request<Context>

CookieManager

Defined in fuchsia.web/cookie.fidl

Provides methods for monitoring and accessing browser cookie state.

GetCookieList

Returns a list of Cookies, optionally limited to those matching url, and optionally name. cookies iterates over the matching cookies, including their values.

Request

Name	Type
url	Url
name	CookieName
cookies	request<CookiesIterator>

ObserveCookieChanges

Observe changes to all cookies named name that would be sent in a request to url.

If neither url nor name are set then all cookies are observed. If only url is set then all cookies for that URL are observed. If both are set then only cookies matching both fields are observed.

changes iterates over a stream of cookie changes. Additions or updates are expressed as complete cookies, while deletions are expressed as cookies with no value set.

Request

Name	Type
url	Url
name	CookieName
changes	request<CookiesIterator>

CookiesIterator

Defined in fuchsia.web/cookie.fidl

Used to iterator over a set of cookies, or a stream of changes to cookies.

GetNext

Fetches the next batch of cookies, or of changes to cookies. RFC6265 does not specify an upper-bound on the number of cookies which may be stored.

Request

Name	Type

Response

Name	Type
changed_cookies	vector<Cookie>

Debug

Defined in fuchsia.web/debug.fidl

The debug service which allows to enable the DevTools service on Contexts.

EnableDevTools

Enables the DevTools service on every subsequent Context creation and delivers subsequent DevTools events to the supplied listener. The callback indicates when the WebEngine is in a debuggable state. Events will be sent to every listener registered with this method.

Request

Name	Type
listener	DevToolsListener

Response

Name	Type

DevToolsListener

Defined in fuchsia.web/debug.fidl

Interface used to observe DevTools service availability events.

OnContextDevToolsAvailable

Called when the DevTools service is available on a new Context.

• listener: Channel over which DevTools events for the new Context will be delivered. This channel will disconnect when the Context is destroyed.

Request

Name	Type
listener	request<DevToolsPerContextListener>

DevToolsPerContextListener

Defined in fuchsia.web/debug.fidl

Interface supplied by the debugging component to observe the DevTools service opening event.

OnHttpPortOpen

Called when the DevTools service starts accepting TCP connections on port. port will remain open until the Context is destroyed.

• port: The port used by the service.

Request

Name	Type
port	uint16

Frame

Defined in fuchsia.web/frame.fidl

AddBeforeLoadJavaScript

Executes a UTF-8 encoded script for every subsequent page load where the Frame's URL has an origin reflected in origins. The script is executed early, prior to the execution of the document's scripts.

Scripts are identified by a client-managed identifier id. Any script previously injected using the same id will be replaced.

The order in which multiple bindings are executed is the same as the order in which the bindings were added. If a script is added which clobbers an existing script of the same id, the previous script's precedence in the injection order will be preserved.

At least one origins entry must be specified. If a wildcard "*" is specified in origins, then the script will be evaluated unconditionally.

If an error occured, the FrameError will be set to one of these values:

• BUFFER_NOT_UTF8: script is not UTF-8 encoded.
• INVALID_ORIGIN: origins is an empty vector.

Request

Name	Type
id	uint64
origins	vector<string>
script	fuchsia.mem/Buffer

Response

Name	Type
result	Frame_AddBeforeLoadJavaScript_Result

ConfigureInputTypes

Enables or disables the processing of the specified types of user inputs. allow specifies whether to enable or disable the specified types. All input types are enabled by default.

Request

Name	Type
types	InputTypes
allow	AllowInputState

CreateView

Creates a new view using the specified view_token. Caller should pass the other end of the token to fuchsia.ui.gfx/ViewHolderArgs to attach the new view to a view tree.

See the description of CreateContextParams.service_directory for additional services that must be present when using this method.

Request

Name	Type
view_token	fuchsia.ui.views/ViewToken

CreateViewWithViewRef

Creates a new view using the specified view_token. Caller should pass the other end of the token to fuchsia.ui.gfx/ViewHolderArgs to attach the new view to a view tree. view_ref can be cloned before passing it to this method, which will allow clients to track the view.

view_ref_control must not have the ZX_RIGHT_DUPLICATE set, or view creation will fail and view_token will be closed.

See the description of CreateContextParams.service_directory for additional services that must be present when using this method.

Request

Name	Type
view_token	fuchsia.ui.views/ViewToken
view_ref_control	fuchsia.ui.views/ViewRefControl
view_ref	fuchsia.ui.views/ViewRef

DisableHeadlessRendering

Stops headless rendering of the Frame.

May only be used on a Context created with the HEADLESS feature flag.

Request

Name	Type

EnableHeadlessRendering

Enables headless rendering of the Frame.

This is used when content depends on layout and/or animation events firing normally. May only be used on a Context created with the HEADLESS feature flag.

Request

Name	Type

ExecuteJavaScript

Executes a UTF-8 encoded script in the Frame if the Frame's URL has an origin which matches entries in origins.

At least one origins entry must be specified. If a wildcard "*" is specified in origins, then the script will be evaluated unconditionally.

Returns the result of executing script, as a JSON-encoded string.

Note that scripts share the same execution context as the document, meaning that document may modify variables, classes, or objects set by the script in arbitrary or unpredictable ways.

If an error occured, the FrameError will be set to one of these values:

• BUFFER_NOT_UTF8: script is not UTF-8 encoded.
• INVALID_ORIGIN: The Frame's current URL does not match any of the values in origins or origins is an empty vector.

Request

Name	Type
origins	vector<string>
script	fuchsia.mem/Buffer

Response

Name	Type
result	Frame_ExecuteJavaScript_Result

ExecuteJavaScriptNoResult

Variant of Frame.ExecuteJavaScript which executes the supplied script without returning a result.

Request

Name	Type
origins	vector<string>
script	fuchsia.mem/Buffer

Response

Name	Type
result	Frame_ExecuteJavaScriptNoResult_Result

ForceContentDimensions

Overrides the dimensions reported to web content. The devicePixelRatio reported to web content will be adjusted in response to changes in the pixel size of the View, rather than changing the size reported to the content. Call with null web_dips to remove any prior forced content dimensions.

Request

Name	Type
web_dips	fuchsia.ui.gfx/vec2?

GetMediaPlayer

Returns a fuchsia.media.sessions2/Player interface through which media (i.e. video/audio) playback in the frame may be observed, and/or controlled. Only one fuchsia.media.sessions2/Player may be active at a time, for each Frame.

Request

Name	Type
player	request<fuchsia.media.sessions2/Player>

GetNavigationController

Returns an interface through which the Frame may be navigated to a desired URL, reloaded, etc.

• controller: An asynchronous interface request for the Frame's NavigationController.

Request

Name	Type
controller	request<NavigationController>

GetPrivateMemorySize

Returns the amount of private (non-shared) physical memory used by the Frame's main document. The returned size might not reflect the memory usage of embedded iframes.

Request

Name	Type

Response

Name	Type
size_bytes	uint64

PostMessage

Posts a message to the frame's onMessage handler.

target_origin restricts message delivery to the specified origin. If target_origin is "*", then the message will be sent to the document regardless of its origin. See the HTML spec section 9.4.3 for more details on how the target origin policy is applied.

If an error occured, the FrameError will be set to one of these values:

• INTERNAL_ERROR: The WebEngine failed to create a message pipe.
• BUFFER_NOT_UTF8: The script in message's data property is not UTF-8 encoded.
• INVALID_ORIGIN: origins is an empty vector.
• NO_DATA_IN_MESSAGE: The data property is missing in message.

Request

Name	Type
target_origin	Url
message	WebMessage

Response

Name	Type
result	Frame_PostMessage_Result

RemoveBeforeLoadJavaScript

Removes a previously added JavaScript snippet identified by id. This is a no-op if there is no JavaScript snippet identified by id.

Request

Name	Type
id	uint64

SetBlockMediaLoading

Sets whether to block all HTMLMediaElements in the frame from fetching and loading media resources.

May be used, for example, to prevent loading media in frames that are not visible.

While media loading is blocked, elements with autoplay set to true will not start playback. The promises returned by calls to play() will remain unresolved until loading is unblocked by a call to this method.

When media loading is unblocked, elements will begin fetching, resource, loading, and playing as appropriate.

Any elements that have begun fetching or loading media resources for the current source before media loading was blocked will continue to fetch, load, and start playback as appropriate. This includes calls to play() even after media loading is blocked.

Request

Name	Type
blocked	bool

SetConsoleLogSink

Specifies where to emit console log output to. By default log output will be routed to a fuchsia.logger/LogSink obtained via the Context's service directory.

• sink: The fuchsia.logger/LogSink to use to emit logs. Passing a null handle resets logging to use the default fuchsia.logger/LogSink.

Request

Name	Type
sink	fuchsia.logger/LogSink?

SetJavaScriptLogLevel

If set to a value other than ConsoleLogLevel.NONE, allows web content to log messages to the fuchsia.logger/LogSink configured for this Frame, via the console object (e.g. using debug(), log(), info(), warn() and error()). The default value is ConsoleLogLevel.NONE.

As the system log may be persisted, it is recommended that ConsoleLogLevel.NONE be used in Incognito and other private browsing modes.

Log lines are written to the fuchsia.logger/LogsSink configured for this Frame, with severities mapped as follows:

• debug(), log() and info() are logged at INFO severity.
• warn() is logged at WARN severity.
• error() is logged at ERROR severity.

Request

Name	Type
level	ConsoleLogLevel

SetMediaSessionId

Sets session_id to pass to the fuchsia.media/AudioConsumer when playing audio. The specified value is not applied retroactively to audio streams that were started before this message is processed. If the caller needs to ensure the value is applied to all streams it should call this method before Frame.GetNavigationController.

Request

Name	Type
session_id	uint64

SetNavigationEventListener

Sets the listener for handling page navigation events.

• listener: The observer to use. Unregisters any existing listener if null.

Request

Name	Type
listener	NavigationEventListener?

SetNavigationEventListener2

Sets the listener for handling page navigation events.

• listener: The observer to use. Unregisters any existing listener if null.
• flags: Flags for optional features that should be enabled for the listener.

Request

Name	Type
listener	NavigationEventListener?
flags	NavigationEventListenerFlags

SetNavigationPolicyProvider

Sets the navigation policy provider for the Frame. When set, the Frame sends NavigationPolicyProvider.EvaluateRequestedNavigation when processing navigation requests. params defines when the message is sent. After sending the EvaluateRequestedNavigation message, the Frame blocks the corresponding navigation until it receives a response.

Should be called before GetNavigationController to ensure that it is applied to all navigations including the first NavigationController.LoadURL request.

Request

Name	Type
params	NavigationPolicyProviderParams
provider	NavigationPolicyProvider

SetPageScale

Sets scale factor (zoom level) that should be applied to web content rendered in this frame. Values above 1.0 make all web content (including text and images) larger, while values below 1.0 will make it smaller. In other words, values above 1.0 are used to zoom in and values below 1.0 zoom out. The overall ratio between physical pixel and CSS pixel is a product of the scale set with this method and the scale provided by Scenic (see fuchsia.ui.gfx.Metrics). That product is visible to the web content as window.devicePixelRatio.

This method does not have any effect on the size of the view on the screen and the resolution at which the view is rendered. Native (non-web) UI elements, such as default scroll bars and default mouse cursor, are not scaled. User may zoom the page further when pinch-zoom is enabled (see InputTypes.GESTURE_PINCH).

Request

Name	Type
scale	float32

SetPermissionState

Sets the permission state for the specified permission and web_origin. By default, all permissions are denied.

Request

Name	Type
permission	PermissionDescriptor
web_origin	Url
state	PermissionState

SetPopupFrameCreationListener

Sets the listener for handling popup frame opened by web content. If no listener is present, then any new popup frame will be blocked.

• listener: The listener to use. Unregisters any existing listener if null.

Request

Name	Type
listener	PopupFrameCreationListener?

SetPreferredTheme

Specifies the color theme reported to web content via the prefers-color-scheme media query. Specifying AUTO requires that the Context have the fuchsia.settings.Display service. If the service is not available, the Frame will disconnect with ZX_ERR_INVALID_ARGS. Valid themes are LIGHT, DARK, and AUTO. The default color scheme is LIGHT. If DEFAULT is specified, the Frame will disconnect with ZX_ERR_INVALID_ARGS.

Request

Name	Type
theme	fuchsia.settings/ThemeType

SetUrlRequestRewriteRules

Supplies a set of UrlRequestRewriteRule to apply on every subsequent URL request.

• rules are cumulative and applied in order.
• rules will be validated before being applied. If rules are invalid, the Frame will be closed with ERR_INVALID_ARGS.
• Frame.SetUrlRequestRewriteRules must not be called again until its acknowledgement callback has been processed. If this happens, the Frame will be closed with ERR_BAD_STATE.

Request

Name	Type
rules	vector<UrlRequestRewriteRule>[4096]

Response

Name	Type

FrameHost

Defined in fuchsia.web/context.fidl

Used by Context clients to delegate Frame hosting capabilities to selected peers.

CreateFrameWithParams

Behaves identically to Context.CreateFrameWithParams.

Request

Name	Type
params	CreateFrameParams
frame	request<Frame>

MessagePort

Defined in fuchsia.web/frame.fidl

Represents one end of an HTML5 MessageChannel. Can be used to send and exchange Messages with the peered MessagePort in the Frame's script context. The port is destroyed when either end of the MessagePort channel is torn down.

PostMessage

Sends a WebMessage to the peer. These are processed in order, one at a time. It is not necessary for the caller to wait for the completion callback before calling MessagePort.PostMessage again.

If an error occured, the FrameError will be set to one of these value:

• BUFFER_NOT_UTF8: The script in message's data property is not UTF-8 encoded.
• NO_DATA_IN_MESSAGE: The data property is missing in message.

Request

Name	Type
message	WebMessage

Response

Name	Type
result	MessagePort_PostMessage_Result

ReceiveMessage

Asynchronously reads the next message from the channel. The client should invoke the callback when it is ready to process another message. Unreceived messages are buffered on the sender's side and bounded by its available resources.

Request

Name	Type

Response

Name	Type
message	WebMessage

NavigationController

Defined in fuchsia.web/navigation.fidl

Provides methods for controlling and querying the navigation state of a Frame.

GetVisibleEntry

Returns information for the currently visible content regardless of loading state, or an empty entry if no content is being displayed.

Request

Name	Type

Response

Name	Type
entry	NavigationState

GoBack

Tells the Frame to navigate to the previous page in its history, if any.

Request

Name	Type

GoForward

Tells the Frame to navigate to the next page in its history, if any.

Request

Name	Type

LoadUrl

Tells the Frame to navigate to a url.

• url: The address to navigate to.
• params: Additional parameters that affect how the resource will be loaded (e.g. cookies, HTTP headers, etc.)

If an error occured, the NavigationControllerError will be set to one of these values:

• INVALID_URL: The url parameter is invalid.
• INVALID_HEADER: At least one of the headers in LoadUrlParams.headers is invalid.

Request

Name	Type
url	Url
params	LoadUrlParams

Response

Name	Type
result	NavigationController_LoadUrl_Result

Reload

Tells the Frame to reload the current page.

Request

Name	Type
type	ReloadType

Stop

Tells the Frame to stop the current navigation if a navigation is ongoing.

Request

Name	Type

NavigationEventListener

Defined in fuchsia.web/navigation.fidl

Interface supplied by the embedder for receiving notifications about navigation events in a Frame.

OnNavigationStateChanged

Called when user-visible navigation state has changed since Frame creation or the last acknowledgement callback, whichever occurred last. change will contain all the differences in navigation state since the last acknowledgement. Any unchanged properties will be left unset in change.

Implementer must call the acknowledgement callback to receive new navigation events.

Request

Name	Type
change	NavigationState

Response

Name	Type

NavigationPolicyProvider

Defined in fuchsia.web/navigation.fidl

EvaluateRequestedNavigation

Called when the Frame is processing a navigation request in one of the phase(s) specified in NavigationPolicyProviderParams. Navigation is paused until the result is received. The returned NavigationDecision defines how the navigation should proceed.

Request

Name	Type
requested_navigation	RequestedNavigation

Response

Name	Type
decision	NavigationDecision

PopupFrameCreationListener

Defined in fuchsia.web/frame.fidl

OnPopupFrameCreated

Called when a Frame has created a new popup frame. Information about the popup frame, and how it was created, is provided via info. Additional popup frames are delivered after the acknowledgement callback is invoked.

Request

Name	Type
frame	Frame
info	PopupFrameCreationInfo

Response

Name	Type

STRUCTS

Context_GetRemoteDebuggingPort_Response

Defined in fuchsia.web/context.fidl

Name	Type	Description	Default
port	uint16		No default

Frame_AddBeforeLoadJavaScript_Response

Defined in fuchsia.web/frame.fidl

Name	Type	Description	Default

Frame_ExecuteJavaScriptNoResult_Response

Defined in fuchsia.web/frame.fidl

Name	Type	Description	Default

Frame_ExecuteJavaScript_Response resource

Defined in fuchsia.web/frame.fidl

Name	Type	Description	Default
result	fuchsia.mem/Buffer		No default

Frame_PostMessage_Response

Defined in fuchsia.web/frame.fidl

Name	Type	Description	Default

MessagePort_PostMessage_Response

Defined in fuchsia.web/frame.fidl

Name	Type	Description	Default

NavigationController_LoadUrl_Response

Defined in fuchsia.web/navigation.fidl

Name	Type	Description	Default

NoArgumentsAction

Defined in fuchsia.web/navigation.fidl

Empty struct used in NavigationDecision for actions that don't hav any arguments.

Name	Type	Description	Default

ENUMS

AllowInputState strict

Type: int32

Defined in fuchsia.web/frame.fidl

Controls whether Frame.ConfigureInputTypes() should allow or deny processing of the specified InputTypes.

Name	Value	Description
ALLOW	1
DENY	2

AutoplayPolicy strict

Type: int32

Defined in fuchsia.web/context.fidl

Specifies the policy for automatic (non user-initiated) playback of video and audio content.

Name	Value	Description
ALLOW	1	All media is permitted to autoplay.
REQUIRE_USER_ACTIVATION	2	Allow autoplay when the document has received a user activation. This can be the result of user action or LoadUrlParams.was_user_activated being set.

ConsoleLogLevel strict

Type: int32

Defined in fuchsia.web/frame.fidl

Name	Value	Description
NONE	100	No logging.
DEBUG	-1	Outputs messages from console.debug() and above levels.
INFO	0	Outputs messages from console.log(), console.info() and above levels.
WARN	1	Outputs messages from console.warn() and console.error().
ERROR	2	Outputs messages from console.error().

ContextError strict

Type: int32

Defined in fuchsia.web/context.fidl

Name	Value	Description
REMOTE_DEBUGGING_PORT_NOT_OPENED	1	The remote debugging service was not opened.

FrameError strict

Type: int32

Defined in fuchsia.web/frame.fidl

Represents the return status of a Frame method.

Name	Value	Description
INTERNAL_ERROR	1	An internal error occured.
BUFFER_NOT_UTF8	2	The provided buffer is not UTF-8 encoded.
INVALID_ORIGIN	3	The Frame's URL does not match any of the origins provided by the caller.
NO_DATA_IN_MESSAGE	4	The required data property is missing from a WebMessage.

LoadUrlReason strict

Type: uint32

Defined in fuchsia.web/navigation.fidl

Characterizes the origin of a NavigationController.LoadUrl request.

Name	Value	Description
LINK	0	Navigation was initiated by the user following a link.
TYPED	1	Navigation was initiated by a user-provided URL.

NavigationControllerError strict

Type: int32

Defined in fuchsia.web/navigation.fidl

Represents the return status of a NavigationController method.

Name	Value	Description
INVALID_URL	1	The provided URL is invalid.
INVALID_HEADER	2	At least one of the provided headers was invalid.

PageType strict

Type: uint32

Defined in fuchsia.web/navigation.fidl

Characterizes the page type in a NavigationState.

Name	Value	Description
NORMAL	0	Regular web page.
ERROR	1	Error page.

PermissionState strict

Type: uint8

Defined in fuchsia.web/frame.fidl

A state for a web permission.

Name	Value	Description
DENIED	1	Permission is denied.
GRANTED	2	Permission is granted.

PermissionType strict

Type: uint16

Defined in fuchsia.web/frame.fidl

Identifies a type of permission that may be granted to a web origin.

Name	Value	Description
MICROPHONE	1	Permission to access microphone(s).
CAMERA	2	Permission to access camera(s).
PROTECTED_MEDIA_IDENTIFIER	3	Permission to use device identifier(s) for EME.
PERSISTENT_STORAGE	4	Permission to use persistent storage.

ReloadType strict

Type: uint32

Defined in fuchsia.web/navigation.fidl

Characterizes the type of reload.

Name	Value	Description
PARTIAL_CACHE	0	Reloads the current entry, bypassing the cache for the main resource.
NO_CACHE	1	Reloads the current entry, bypassing the cache entirely.

UrlRequestAction strict

Type: int32

Defined in fuchsia.web/url_request_rewrite_rules.fidl

Name	Value	Description
ALLOW	1	Allow the request to be processed.
DENY	2	Block the request.

TABLES

ContentDirectoryProvider resource

Defined in fuchsia.web/context.fidl

Defines a provider which hosts resources from a fuchsia.io/Directory. Content can GET resource files via the provider, but not enumerate directories. Resources can be accessed by their URLs: fuchsia-dir://<provider-name>/<path/to/resource>

By default the MIME types of files are determined automatically by "sniffing" the contents of the files. No content encoding will be declared, which browsers will interpret as meaning "text/plain".

Content type and encoding metadata may optionally be specified explicitly by metadata files, which reside alongside the file. Metadata is expressed in JSON files, named after the files they describe with a "._metadata" suffix.

For example, the file "index.html" would have the a metadata file called "index.html._metadata", with the following contents:

{
  "charset": "utf-8",
  "mime": "text/html"
}

Ordinal	Name	Type	Description
1	name	string[255]	Name of the provider. Must be non-empty and composed solely of alphanumerics, dots, and dashes.
2	directory	fuchsia.io/Directory	Directory containing the files served by this provider.

Cookie resource

Defined in fuchsia.web/cookie.fidl

Ordinal	Name	Type	Description
1	id	CookieId	A table with fields to identify a cookie.
2	value	string	The cookie value. RFC6265 does not specify an upper limit on cookie size, but recommends that at least 4096 bytes are supported.

CookieId

Defined in fuchsia.web/cookie.fidl

Ordinal	Name	Type	Description
1	name	CookieName	An RFC2616 "token" chosen by the site to identify the cookie.
2	domain	string[255]	The RFC1034 "subdomain" to which this cookie is scoped. e.g. "example.com" allows access from all *.example.com sub-domains.
3	path	string[65536]	The URL "path" prefix to which this cookie is scoped. e.g. "/" allows access from all paths.

CreateContextParams resource

Defined in fuchsia.web/context.fidl

Parameters specifying the configuration for a new Context.

Ordinal	Name	Type	Description
1	service_directory	fuchsia.io/Directory	Service directory to be used by the context. The following services must be present in the directory: fuchsia.device/NameProvider fuchsia.fonts/Provider fuchsia.intl/PropertyProvider fuchsia.logger/LogSink fuchsia.memorypressure/Provider fuchsia.process/Launcher fuchsia.sysmem/Allocator The following services must be present in order to render web content in a Scenic view using Frame.CreateView or Frame.CreateViewWithViewRef: fuchsia.accessibility.semantics/SemanticsManager fuchsia.ui.input/ImeService fuchsia.ui.input/ImeVisibilityService fuchsia.ui.scenic/Scenic
2	data_directory	fuchsia.io/Directory	Handle to the directory that will contain the Context's persistent data. If it is left unset, then the created Context will be stateless, with all of its data discarded upon Context destruction. If set, data_directory must not be shared with any other Context.
3	user_agent_product	string[128]	Optional string describing the embedding product to append to the User-Agent string. See the specification for the HTTP User-Agent header. Requires that user_agent_version is also specified.
4	user_agent_version	string[128]	Optional version for the embedding product to append to the User-Agent string. Requires that user_agent_product is also specified.
5	remote_debugging_port	uint16	Enables Frames to be created with remote debugging enabled using the DevTools protocol. If port is 0, then an ephemeral port will be used, which can be queried via the Context.GetRemoteDebuggingPort API.
6	content_directories	vector<ContentDirectoryProvider>[100]	List of providers whose contents will be served by fuchsia-dir:// URLs.
7	features	ContextFeatureFlags	Optional features that should be enabled for this context. Some features may also require additional services in service_directory.
8	playready_key_system	string[128]	Enables PlayReady CDM for the Context using the specified string as a key system string. The string should be a reverse domain name, as required by EME API. Requires fuchsia.media.drm/PlayReady service. Requires that a cdm_data_directory be specified in CreateContextParams.
9	unsafely_treat_insecure_origins_as_secure	vector<string>[100]	Treat given insecure origins as secure origins. For the definition of secure contexts, see Secure Contexts and origin trustworthiness. Example value: {"http://a.com", "http://b.com"}.
10	cors_exempt_headers	vector<vector<uint8>>	Specifies a set of header names for which Cross-Origin Resource Sharing (CORS) checks should not be enforced.
11	cdm_data_directory	fuchsia.io/Directory	Specifies the storage to use to persistent content licensing related data (e.g. provisioning data, persistent session data). By default these data will be placed under the data_directory, if specified. If neither data_directory nor cdm_data_directory are specified, then content licensing features requiring persistent storage (e.g. persistent licensing sessions) will not be available to the Context. Note that not all content licensing systems support persistent sessions, regardless of whether persistent storage is provided.
12	cdm_data_quota_bytes	uint64	Specifies a target maximum size for cdm_data_directory contents, in bytes. If the amount of persisted CDM data exceeds this threshold, then the Context will attempt to purge some data to meet the specified quota.
13	data_quota_bytes	uint64	Specifies a target maximum size for data_directory contents, in bytes. The Context will attempt to limit browsing state (e.g. cookies, LocalStorage) to not exceed the specified size.

CreateFrameParams resource

Defined in fuchsia.web/context.fidl

Parameters specifying the configuration for a new Frame.

Ordinal	Name	Type	Description
1	enable_remote_debugging	bool	Set to true to enable remote debugging. The Frame will be closed with ERR_INVALID_ARGS if remote_debugging_port was not set in CreateContextParams.
2	debug_name	string	Set to give the Frame a name to help distinguish it in debug contexts , such as system log output. For example, the name may be added to messages from web content when they are logged to the system logger. The name does not affect user- or web-visible behavior. Popup Frames created by the Frame will have a name derived from the parent Frame's name.
3	autoplay_policy	AutoplayPolicy	Sets the autoplay policy for the Frame. If omitted, the default policy is REQUIRE_USER_ACTIVATION. CreateFrame will fail with ZX_ERR_NOT_SUPPORTED if the value specified is not supported by the Context.
4	explicit_sites_filter_error_page	fuchsia.mem/Data	Enables automatic blocking of navigations to explicit sites, and specifies the error page content, in HTML, to be loaded in the Frame when a navigation is canceled by the filter. Applies to navigations in all frames within the Frame. When navigation of the main document is canceled, the Frame's NavigationState.PageType is ERROR. If set to an empty buffer, a default error message will be displayed. If set and such filtering is not supported, the Frame will disconnect with ZX_ERR_NOT_SUPPORTED.

Favicon resource

Defined in fuchsia.web/navigation.fidl

Used to represent a favicon for a page. An empty table (all fields are unset) is used to indicate that the page doesn't have a favicon.

Ordinal	Name	Type	Description
1	data	fuchsia.mem/Buffer	The image content encoded as an RGBA bitmap with premultiplied alpha channel. The data is densely packed, so the stride is always 4 * width and the total size is 4 * width * height.
2	width	uint32	The width of the image.
3	height	uint32	The height of the image.

LoadUrlParams resource

Defined in fuchsia.web/navigation.fidl

Additional parameters for modifying the behavior of NavigationController.LoadUrl.

Ordinal	Name	Type	Description
1	type	LoadUrlReason	Provides a hint to the browser UI about how NavigationController.LoadUrl was triggered.
2	referrer_url	Url	The URL that linked to the resource being requested.
3	was_user_activated	bool	Should be set to true to propagate user activation to the frame. User activation implies that the user is interacting with the web frame. It enables some web features that are not available otherwise. For example, autoplay will work only when this flag is set to true.
4	headers	vector<fuchsia.net.http/Header>	Custom HTTP headers. RFC7540 does not specify a limit on the number nor size of headers.

NavigationPolicyProviderParams

Defined in fuchsia.web/navigation.fidl

Used to specify which navigation events should be delegated to NavigationPolicyProvider.

Ordinal	Name	Type	Description
1	main_frame_phases	NavigationPhase	Specifies the set of navigation phases in the main frame that should be evaluated.
2	subframe_phases	NavigationPhase	Specifies the set of navigation phases in subframes that should be evaluated.

NavigationState resource

Defined in fuchsia.web/navigation.fidl

Contains information about the Frame's navigation state.

Ordinal	Name	Type	Description
1	url	Url	The page's URL.
2	title	string	The user-visible page title. While W3C style recommendation is that HTML TITLE tags not exceed 64 characters in length, there is no actual limit.
3	page_type	PageType	Indicates whether this was a navigation to an error page.
4	can_go_forward	bool	Indicates if there is a following navigation.
5	can_go_back	bool	Indicates if there is a previous navigation.
6	is_main_document_loaded	bool	Indicates that the main document's statically declared resources have been loaded.
7	favicon	Favicon	Current favicon for the page. The field is set only when the FAVICON flag is set for the NavigationEventListener and the favicon has changed.

PermissionDescriptor

Defined in fuchsia.web/frame.fidl

Describes a web permission. In the future, it may be extended with type-specific fields.

Ordinal	Name	Type	Description
1	type	PermissionType

PopupFrameCreationInfo resource

Defined in fuchsia.web/frame.fidl

Specifies additional information about a newly created popup frame.

Ordinal	Name	Type	Description
1	initial_url	Url	The URL to which the popup frame was initially navigated.
2	initiated_by_user	bool	Set if the popup frame was created in response to UI interaction from the user (e.g. a link was clicked).

RequestedNavigation

Defined in fuchsia.web/navigation.fidl

Ordinal	Name	Type	Description
1	id	NavigationId	Unique ID of the navigation.
2	phase	NavigationPhase	Current navigation phase. Exactly one bit will be set.
3	is_main_frame	bool	Whether the navigation is taking place in the main frame versus in a subframe.
4	is_same_document	bool	Whether the navigation happened without changing the document.
5	is_http_post	bool	Whether the navigation is a POST request.
6	url	Url	The current target URL of the navigation. This may change for the same navigation after encountering a server redirect.
7	has_gesture	bool	Whether the navigation was initiated by a user gesture.
8	was_server_redirect	bool	Whether the navigation has encountered a server redirect or not.

UrlRequestRewriteAddHeaders

Defined in fuchsia.web/url_request_rewrite_rules.fidl

Adds headers to the URL request. If a header is already present in the original URL request, it will be overwritten.

• headers must be set.
• Each fuchsia.net.http/Header in headers must have a valid HTTP header name and value, per RFC 7230 section 3.2.

Ordinal	Name	Type	Description
1	headers	vector<fuchsia.net.http/Header>[4096]

UrlRequestRewriteAppendToQuery

Defined in fuchsia.web/url_request_rewrite_rules.fidl

Appends query to the URL query. If the URL request already has a query, query will be appended to it, preceded by &. Otherwise, the URL's query will be set to query.

• query must be set.
• query must be a valid URL-query string.

Ordinal	Name	Type	Description
1	query	Url

UrlRequestRewriteRemoveHeader

Defined in fuchsia.web/url_request_rewrite_rules.fidl

If query_pattern in the URL query, removes header_name from the list of headers. If query_pattern is not set, removes header_name from the list of headers unconditionally.

• header_name must be set.
• header_name must be a valid HTTP header name, per RFC 7230 section 3.2.

Ordinal	Name	Type	Description
1	query_pattern	Url
2	header_name	vector<uint8>[4096]

UrlRequestRewriteReplaceUrl

Defined in fuchsia.web/url_request_rewrite_rules.fidl

If the URL in the URL request ends with url_ends_with, rewrites the URL to new_url.

• url_ends_with and new_url must be set.
• url_ends_with must be a valid path-relative-URL string.
• new_url must be a valid URL string.

Ordinal	Name	Type	Description
1	url_ends_with	Url
2	new_url	Url

UrlRequestRewriteRule

Defined in fuchsia.web/url_request_rewrite_rules.fidl

Ordinal	Name	Type	Description
1	hosts_filter	vector<string>[4096]	Set of hosts to apply the rules to. If not set, the rule will apply to every request, independent of host.
2	schemes_filter	vector<string>[4096]	Set of schemes to apply the rules to. If not set, the rule will apply to every request, independent of scheme.
3	rewrites	vector<UrlRequestRewrite>[4096]	URL request rewrites to apply.
4	action	UrlRequestAction	Specifies the action to take for requests matching the filter criteria. Requests are allowed by default.

UrlRequestRewriteSubstituteQueryPattern

Defined in fuchsia.web/url_request_rewrite_rules.fidl

If pattern is found in the URL request query, replaces it with substitution.

• pattern and substitution must be set.
• substitution must be a valid URL-query string.

Ordinal	Name	Type	Description
1	pattern	Url
2	substitution	Url

WebMessage resource

Defined in fuchsia.web/frame.fidl

Ordinal	Name	Type	Description
1	data	fuchsia.mem/Buffer	The message payload, encoded as an UTF-8 string. This is a required property.
2	incoming_transfer	vector<IncomingTransferable>	Optional list of objects transferred into the MessagePort from the FIDL client.
3	outgoing_transfer	vector<OutgoingTransferable>	Optional list of objects transferred out of the MessagePort to the FIDL client.

UNIONS

Context_GetRemoteDebuggingPort_Result strict

Defined in fuchsia.web/context.fidl

Name	Type	Description
response	Context_GetRemoteDebuggingPort_Response
err	ContextError

Frame_AddBeforeLoadJavaScript_Result strict

Defined in fuchsia.web/frame.fidl

Name	Type	Description
response	Frame_AddBeforeLoadJavaScript_Response
err	FrameError

Frame_ExecuteJavaScriptNoResult_Result strict

Defined in fuchsia.web/frame.fidl

Name	Type	Description
response	Frame_ExecuteJavaScriptNoResult_Response
err	FrameError

Frame_ExecuteJavaScript_Result strict resource

Defined in fuchsia.web/frame.fidl

Name	Type	Description
response	Frame_ExecuteJavaScript_Response
err	FrameError

Frame_PostMessage_Result strict

Defined in fuchsia.web/frame.fidl

Name	Type	Description
response	Frame_PostMessage_Response
err	FrameError

IncomingTransferable flexible resource

Defined in fuchsia.web/frame.fidl

Name	Type	Description
message_port	MessagePort

MessagePort_PostMessage_Result strict

Defined in fuchsia.web/frame.fidl

Name	Type	Description
response	MessagePort_PostMessage_Response
err	FrameError

NavigationController_LoadUrl_Result strict

Defined in fuchsia.web/navigation.fidl

Name	Type	Description
response	NavigationController_LoadUrl_Response
err	NavigationControllerError

NavigationDecision strict resource

Defined in fuchsia.web/navigation.fidl

Navigation action that should be taken in response to a navigation request. Returned from NavigationPolicyProvider.EvaluateRequestedNavigation.

Name	Type	Description
proceed	NoArgumentsAction	Navigation should proceed normally.
abort	NoArgumentsAction	Navigation should be aborted. The frame should stay on the current page.

OutgoingTransferable flexible resource

Defined in fuchsia.web/frame.fidl

Name	Type	Description
message_port	request<MessagePort>

UrlRequestRewrite flexible

Defined in fuchsia.web/url_request_rewrite_rules.fidl

Name	Type	Description
add_headers	UrlRequestRewriteAddHeaders	Adds a set of headers to a URL request.
remove_header	UrlRequestRewriteRemoveHeader	Removes a header based on the presence of a pattern in the URL query.
substitute_query_pattern	UrlRequestRewriteSubstituteQueryPattern	Substitutes a pattern in the URL query.
replace_url	UrlRequestRewriteReplaceUrl	Replaces a URL if the original URL ends with a pattern.
append_to_query	UrlRequestRewriteAppendToQuery	Appends to the URL query.

BITS

ContextFeatureFlags strict

Type: uint64

Defined in fuchsia.web/context.fidl

Feature flags that allow augmenting Context behavior. Some features require additional services in the service directory provided during context initialization. See CreateContextParams.service_directory.

Name	Value	Description
NETWORK	1	Enables network access. Requires the following services: fuchsia.net.name.Lookup fuchsia.net.interfaces/State fuchsia.posix.socket/Provider
AUDIO	2	Enables audio input and output. Requires the following services: fuchsia.media/Audio fuchsia.media/SessionAudioConsumerFactory
VULKAN	4	Enables GPU-accelerated rendering of the web content. Requires the following services: fuchsia.vulkan.loader/Loader
HARDWARE_VIDEO_DECODER	8	Enables hardware video decoding. VULKAN must be enabled as well. Requires the following service: fuchsia.mediacodec/CodecFactory
HARDWARE_VIDEO_DECODER_ONLY	16	Disables video codecs that cannot be decoded in hardware. Software decoders will only be used as fallbacks for hardware decoders, such as when insufficient resources are available. Requires the HARDWARE_VIDEO_DECODER flag.
WIDEVINE_CDM	32	Enables Widevine CDM modules for EME API. VULKAN feature must be enabled as well. Requires fuchsia.media.drm/Widevine service. Requires that a cdm_data_directory be specified in CreateContextParams.
HEADLESS	64	Allows embedders to render web content without graphical output or Scenic. Not compatible with the VULKAN flag.
LEGACYMETRICS	128	Report telemetry data to the fuchsia.legacymetrics/MetricsRecorder.
KEYBOARD	256	Enables input events for keyboard keypresses. Requires fuchsia.ui.input3/Keyboard, from which the events are obtained.
VIRTUAL_KEYBOARD	512	Enables the use of onscreen virtual keyboards. The implementation will manage the state of the keyboard in response to input/focus events in web content. Requires the fuchsia.input.virtualkeyboard/ControllerCreator service and the KEYBOARD ContextFeatureFlag.

InputTypes strict

Type: uint64

Defined in fuchsia.web/frame.fidl

Identifies the types of input events which may be handled by a View.

Name	Value	Description
KEY	1	Keyboard events.
MOUSE_CLICK	2	Mouse button events, for any button.
MOUSE_WHEEL	4	Mouse scroll wheel events.
MOUSE_MOVE	8	Mouse movement events.
GESTURE_TAP	16	Single tapping with one finger.
GESTURE_PINCH	32	Pinching (for zooming).
GESTURE_DRAG	64	Dragging a finger (for scrolling).
ALL	9223372036854775808	Matches all input types.

NavigationEventListenerFlags strict

Type: uint64

Defined in fuchsia.web/frame.fidl

Flags clients can set when connecting a NavigationEventListener to indicates interest in optional features.

Name	Value	Description
FAVICON	1	Enables favicon field in NavigationState.

NavigationPhase strict

Type: uint32

Defined in fuchsia.web/navigation.fidl

Identifies a navigation phase.

Name	Value	Description
START	1	Navigation is being started.
REDIRECT	2	Navigation was redirected.
PROCESS_RESPONSE	4	Navigation response is being processed. At this point navigation hasn't been committed yet, so it is not too late to cancel it.
FAIL	8	Navigation has failed.

CONSTANTS

Name	Value	Type	Description
MAX_HEADERS_COUNT	4096	int32
MAX_HOST_LENGTH	255	int32
MAX_RULE_COUNT	4096	int32
MAX_SCHEME_AND_HOST_LENGTH	513	int32
MAX_URL_LENGTH	65536	int32
MAX_URL_SCHEME_NAME_LENGTH	255	int32

TYPE ALIASES

Name	Value	Description
CookieName	string[MAX]
NavigationId	uint64	Unique identifier of a navigation. Can be used to correlate different phases for the same navigation. Guaranteed to be unique for all navigations in the same Context.
Url	string[MAX_URL_LENGTH]
UrlHostName	string[MAX_HOST_LENGTH]
UrlSchemeAndHostName	string[MAX_SCHEME_AND_HOST_LENGTH]
UrlSchemeName	string[MAX_URL_SCHEME_NAME_LENGTH]