Fired when a server-initiated redirect is about to occur.
Note that you can't pass "blocking"
for this event, so you can't modify or cancel the request from this event: it's informational only.
browser.webRequest.onBeforeRedirect.addListener( listener, // function filter, // object extraInfoSpec // optional array of strings ) browser.webRequest.onBeforeRedirect.removeListener(listener) browser.webRequest.onBeforeRedirect.hasListener(listener)
Events have three functions:
addListener(callback, filter, extraInfoSpec)
removeListener(listener)
listener
argument is the listener to remove.hasListener(listener)
listener
is registered for this event. Returns true
if it is listening, false
otherwise.callback
A function that will be called when this event occurs. The function will be passed the following arguments:
filter
webRequest.RequestFilter
. A filter that restricts the events that will be sent to this listener.extraInfoSpec
Optional
array
of string
. Extra options for the event. You can pass just one value:"
responseHeaders
"
: include responseHeaders
in the details
object passed to the listenercookieStoreId
string
. If the request is from a tab open in a contextual identity, the cookie store ID of the contextual identity.documentUrl
string
. URL of the document in which the resource will be loaded. For example, if the web page at "https://example.com" contains an image or an iframe, then the documentUrl
for the image or iframe will be "https://example.com". For a top-level document, documentUrl
is undefined.frameId
integer
. Zero if the request happens in the main frame; a positive value is the ID of a subframe in which the request happens. If the document of a (sub-)frame is loaded (type
is main_frame
or sub_frame
), frameId
indicates the ID of this frame, not the ID of the outer frame. Frame IDs are unique within a tab.fromCache
boolean
. Indicates if this response was fetched from disk cache.incognito
boolean
. Whether the request is from a private browsing window.ip
string
. The IP address of the server the request was sent to. It may be a literal IPv6 address.method
string
. Standard HTTP method: for example, "GET" or "POST".originUrl
string
. URL of the resource which triggered the request. For example, if "https://example.com" contains a link, and the user clicks the link, then the originUrl
for the resulting request is "https://example.com".
The originUrl
is often but not always the same as the documentUrl
. For example, if a page contains an iframe, and the iframe contains a link that loads a new document into the iframe, then the documentUrl
for the resulting request will be the iframe's parent document, but the originUrl
will be the URL of the document in the iframe that contained the link.
parentFrameId
integer
. ID of the frame that contains the frame which sent the request. Set to -1 if no parent frame exists.proxyInfo
object
. This property is present only if the request is being proxied. It contains the following properties:
host
string
. The hostname of the proxy server.port
integer
. The port number of the proxy server.type
string
. The type of proxy server. One of:
username
string
. Username for the proxy service.proxyDNS
boolean
. True if the proxy will perform domain name resolution based on the hostname supplied, meaning that the client should not do its own DNS lookup.failoverTimeout
integer
. Failover timeout in seconds. If the proxy connection fails, the proxy will not be used again for this period.redirectUrl
string
. The new URL.requestId
string
. The ID of the request. Request IDs are unique within a browser session, so you can use them to relate different events associated with the same request.responseHeaders
webRequest.HttpHeaders
. The HTTP response headers that were received along with this redirect.statusCode
integer
. Standard HTTP status code returned by the server.statusLine
string
. HTTP status line of the response or the 'HTTP/0.9 200 OK' string for HTTP/0.9 responses (i.e., responses that lack a status line) or an empty string if there are no headers.tabId
integer
. The ID of the tab in which the request takes place. Set to -1 if the request isn't related to a tab.thirdParty
boolean
. Indicates whether the request and its content window hierarchy are third party.timeStamp
number
. The time when this event fired, in milliseconds since the epoch.type
webRequest.ResourceType
. The type of resource being requested: for example, "image", "script", "stylesheet".url
string
. Target of the request.urlClassification
object
. The type of tracking associated with the request, if with the request has been classified by Firefox Tracking Protection. This is an object with the following properties:firstParty
array
of strings
. Classification flags for the request's first party.thirdParty
array
of strings
. Classification flags for the request or its window hierarchy's third parties.fingerprinting
and fingerprinting_content
: indicates the request is involved in fingerprinting. fingerprinting_content
indicates the request is loaded from an origin that has been found to fingerprint but is not considered to participate in tracking, such as a payment provider.cryptomining
and cryptomining_content
: similar to the fingerprinting category but for cryptomining resources.tracking
, tracking_ad
, tracking_analytics
, tracking_social
, and tracking_content
: indicates the request is involved in tracking. tracking
is any generic tracking request, the ad
, analytics
, social
, and content
suffixes identify the type of tracker.any_basic_tracking
: a meta flag that combines any tracking and fingerprinting flags, excluding tracking_content
and fingerprinting_content
.any_strict_tracking
: a meta flag that combines any tracking and fingerprinting flags, including tracking_content
and fingerprinting_content
.any_social_tracking
: a meta flag that combines any social tracking flags.Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
onBeforeRedirect |
Yes |
14 |
46 |
? |
Yes |
14
extraInfoSpec options are not supported.
|
? |
? |
48 |
? |
? |
? |
var target = "https://developer.mozilla.org/*"; /* e.g. "https://developer.mozilla.org/" "https://developer.mozilla.org/en-US/" */ function logResponse(responseDetails) { console.log(responseDetails.url); console.log(responseDetails.redirectUrl); } browser.webRequest.onBeforeRedirect.addListener( logResponse, {urls: [target]} );
Note: This API is based on Chromium's chrome.webRequest
API. This documentation is derived from web_request.json
in the Chromium code.
Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.
© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/onBeforeRedirect