chrome.types
- Description
The
chrome.types
API contains type declarations for Chrome.
Chrome settings
The ChromeSetting
prototype provides a common set of functions (get()
, set()
, and clear()
) as well as an event publisher (onChange
) for settings of the Chrome browser. The proxy settings examples demonstrate how these functions are intended to be used.
Scope and life cycle
Chrome distinguishes between three different scopes of browser settings:
regular
- Settings set in the
regular
scope apply to regular browser windows and are inherited by incognito windows if they are not overwritten. These settings are stored to disk and remain in place until they are cleared by the governing extension, or the governing extension is disabled or uninstalled. incognito_persistent
- Settings set in the
incognito_persistent
scope apply only to incognito windows. For these, they overrideregular
settings. These settings are stored to disk and remain in place until they are cleared by the governing extension, or the governing extension is disabled or uninstalled. incognito_session_only
- Settings set in the
incognito_session_only
scope apply only to incognito windows. For these, they overrideregular
andincognito_persistent
settings. These settings are not stored to disk and are cleared when the last incognito window is closed. They can only be set when at least one incognito window is open.
Precedence
Chrome manages settings on different layers. The following list describes the layers that may influence the effective settings, in increasing order of precedence.
- System settings provided by the operating system
- Command-line parameters
- Settings provided by extensions
- Policies
As the list implies, policies might overrule any changes that you specify with your extension. You can use the get()
function to determine whether your extension is capable of providing a setting or whether this setting would be overridden.
As discussed above, Chrome allows using different settings for regular windows and incognito windows. The following example illustrates the behavior. Assume that no policy overrides the settings and that an extension can set settings for regular windows (R) and settings for incognito windows (I).
- If only (R) is set, these settings are effective for both regular and incognito windows.
- If only (I) is set, these settings are effective for only incognito windows. Regular windows use the settings determined by the lower layers (command-line options and system settings).
- If both (R) and (I) are set, the respective settings are used for regular and incognito windows.
If two or more extensions want to set the same setting to different values, the extension installed most recently takes precedence over the other extensions. If the most recently installed extension sets only (I), the settings of regular windows can be defined by previously installed extensions.
The effective value of a setting is the one that results from considering the precedence rules. It is used by Chrome.
Summary
- Types
Types
ChromeSetting
An interface that allows access to a Chrome browser setting. See accessibilityFeatures
for an example.
Properties
- onChange
event
Fired after the setting changes.
The
onChange.addListener
function looks like:(callback: function) => {...}
- callback
function
The
callback
parameter looks like:(details: object) => void
- details
object
- incognitoSpecific
boolean optional
Whether the value that has changed is specific to the incognito session. This property will only be present if the user has enabled the extension in incognito mode.
- levelOfControl
The level of control of the setting.
- value
T
The value of the setting after the change.
- clear
function
PromiseClears the setting, restoring any default value.
The
clear
function looks like:(details: object, callback?: function) => {...}
- details
object
Which setting to clear.
- scope
ChromeSettingScope optional
Where to clear the setting (default: regular).
- callback
function optional
The
callback
parameter looks like:() => void
- returns
Promise<void>
Chrome 96+Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.
- get
function
PromiseGets the value of a setting.
The
get
function looks like:(details: object, callback?: function) => {...}
- details
object
Which setting to consider.
- incognito
boolean optional
Whether to return the value that applies to the incognito session (default false).
- callback
function optional
The
callback
parameter looks like:(details: object) => void
- details
object
Details of the currently effective value.
- incognitoSpecific
boolean optional
Whether the effective value is specific to the incognito session. This property will only be present if the
incognito
property in thedetails
parameter ofget()
was true. - levelOfControl
The level of control of the setting.
- value
T
The value of the setting.
- returns
Promise<object>
Chrome 96+Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.
- set
function
PromiseSets the value of a setting.
The
set
function looks like:(details: object, callback?: function) => {...}
- details
object
Which setting to change.
- scope
ChromeSettingScope optional
Where to set the setting (default: regular).
- value
T
The value of the setting. Note that every setting has a specific value type, which is described together with the setting. An extension should not set a value of a different type.
- callback
function optional
The
callback
parameter looks like:() => void
- returns
Promise<void>
Chrome 96+Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.
ChromeSettingScope
The scope of the ChromeSetting. One of
regular
: setting for the regular profile (which is inherited by the incognito profile if not overridden elsewhere),regular\_only
: setting for the regular profile only (not inherited by the incognito profile),incognito\_persistent
: setting for the incognito profile that survives browser restarts (overrides regular preferences),incognito\_session\_only
: setting for the incognito profile that can only be set during an incognito session and is deleted when the incognito session ends (overrides regular and incognito_persistent preferences).
Type
"regular"
,"regular_only"
,"incognito_persistent"
, or"incognito_session_only"
LevelOfControl
One of
not\_controllable
: cannot be controlled by any extensioncontrolled\_by\_other\_extensions
: controlled by extensions with higher precedencecontrollable\_by\_this\_extension
: can be controlled by this extensioncontrolled\_by\_this\_extension
: controlled by this extension
Type
"not_controllable"
,"controlled_by_other_extensions"
,"controllable_by_this_extension"
, or"controlled_by_this_extension"