Fired when a request could not be processed due to an error: for example, a lack of Internet connectivity.
The error is passed to the listener as the
error
特性为
details
对象。
Note that this event is not fired for HTTP errors (4XX or 5XX responses): these will go through the normal stages of a request, calling any event listeners, and setting
details.statusCode
to report the error.
This event is informational only.
browser.webRequest.onErrorOccurred.addListener(
listener, // function
filter // object
)
browser.webRequest.onErrorOccurred.removeListener(listener)
browser.webRequest.onErrorOccurred.hasListener(listener)
Events have three functions:
addListener(callback, filter)
Adds a listener to this event.
removeListener(listener)
Stop listening to this event. The
listener
argument is the listener to remove.
hasListener(listener)
校验是否
listener
is registered for this event. Returns
true
if it is listening,
false
否则。
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.
cookieStoreId
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.
error
string
. The error description. This string is an internal error string, may vary from one browser to another, and is not guaranteed to stay the same between releases.
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.
方法
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".
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
对象
. 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.
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.
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
编号
. 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
对象
. 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.
The classification flags include:
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
，和
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.
BCD tables only load in the browser
var target = "<all_urls>";
/*
e.g., with no network:
"https://developer.mozilla.org/en-US/"
NS_ERROR_NET_ON_RESOLVED in Firefox
net::ERR_INTERNET_DISCONNECTED in Chrome
*/
function logError(responseDetails) {
console.log(responseDetails.url);
console.log(responseDetails.error);
}
browser.webRequest.onErrorOccurred.addListener(
logError,
{urls: [target]}
);
注意：
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.
最后修改： , 由 MDN 贡献者