This type is a string, which represents the context in which a resource was fetched in a web request.
It's used to filter the requests you listen to using the webRequest API. For example: you can listen to requests only for images, or only for scripts.
Values of this type are strings. Possible values are:
beacon
Requests sent through the Beacon API .
csp_report
Requests sent to the
report-uri
given in the
Content-Security-Policy
header, when an attempt to violate the policy is detected.
font
Web fonts loaded for a
@font-face
CSS rule.
image
Resources loaded to be rendered as image, except for
imageset
on browsers that support that type (see browser compatibility below).
imageset
Images loaded by a
<picture>
element or given in an
<img>
element's
srcset
属性。
main_frame
Top-level documents loaded into a tab.
media
Resources loaded by a
<video>
or
<audio>
元素。
对象
Resources loaded by an
<object>
or
<embed>
元素。
Browsers that don't have a dedicated
object_subrequest
type (see browser compatibility below), also label subsequent requests sent by the plugin as
对象
.
object_subrequest
Requests sent by plugins.
ping
Requests sent to the URL given in a hyperlink's
ping
attribute, when the hyperlink is followed.
Browsers that don't have a dedicated
beacon
type (see browser compatibility below), also label requests sent through the Beacon API as
ping
.
script
Code that is loaded to be executed by a
<script>
element or running in a
Worker
.
speculative
In a speculative connection the browser has determined that a request to a URI may be coming soon, so it starts a TCP and/or TLS handshake immediately, so it is ready more quickly when the resource is actually requested.
样式表
CSS stylesheets loaded to describe the representation of a document.
sub_frame
Documents loaded into an
<iframe>
or
<frame>
元素。
web_manifest
Web App Manifests loaded for websites that can be installed to the homescreen.
websocket
Requests initiating a connection to a server through the WebSocket API .
xbl
XBL bindings loaded to extend the behavior of elements in a document.
xml_dtd
DTDs loaded for an XML document.
xmlhttprequest
Requests sent by an
XMLHttpRequest
object or through the
抓取 API
.
xslt
XSLT stylesheets loaded for transforming an XML document.
other
Resources that aren't covered by any other available type.
BCD tables only load in the browser
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