Extensions built with WebExtension APIs are designed to be compatible with Chrome and Opera extensions. As far as possible, extensions written for those browsers should run on Firefox with minimal changes.
However, there are significant differences between Chrome, Firefox, and Edge. In particular:
manifest.json
keys differs across browsers. See the
"Browser compatibility" section
在
manifest.json
page for more details.
浏览器
名称空间。
chrome
namespace. (cf.
Chrome bug 798169
)
The rest of this page summarizes these and other incompatibilities.
浏览器
名称空间。
browser.browserAction.setIcon({path: "path/to/icon.png"});
chrome
名称空间。
chrome.browserAction.setIcon({path: "path/to/icon.png"});
function logCookie(c) {
console.log(c);
}
function logError(e) {
console.error(e);
}
let setCookie = browser.cookies.set(
{url: "https://developer.mozilla.org/"}
);
setCookie.then(logCookie, logError);
runtime.lastError
to communicate errors.
function logCookie(c) {
if (chrome.runtime.lastError) {
console.error(chrome.runtime.lastError);
} else {
console.log(c);
}
}
chrome.cookies.set(
{url: "https://developer.mozilla.org/"},
logCookie
);
As a porting aid, the Firefox implementation of WebExtensions supports
chrome
, using callbacks, as well as
浏览器
, using promises. This means that many Chrome extensions will just work in Firefox without any changes.
注意： However, this is not part of the WebExtensions standard. and may not be supported by all compliant browsers.
If you choose to write your extension to use
浏览器
and promises, then Firefox also provides a polyfill that will enable it to run in Chrome:
https://github.com/mozilla/webextension-polyfill
.
The page Browser support for JavaScript APIs includes compatibility tables for all APIs that have any support in Firefox. Where there are caveats around support for a given API item, this is indicated in these tables with an asterisk "*" and in the reference page for the API item, the caveats are explained.
These tables are generated from compatibility data stored as JSON files in GitHub .
The rest of this section describes compatibility issues that are not already captured in the tables.
For
notifications.create()
，采用
type "basic"
:
iconUrl
is optional.
iconUrl
被要求。
When the user clicks on a notification:
若调用
notifications.create()
more than once in rapid succession:
chrome.notifications.create()
callback function is not a sufficient delay to prevent this.
Firefox's
proxy
API followed a completely different design from Chrome's Proxy API.
Because this API is incompatible with Chrome's
proxy
API, the Firefox proxy API is only available through the
浏览器
名称空间。
当使用
tabs.executeScript()
or
tabs.insertCSS()
:
To work cross-browser, you can specify the path as an absolute URL, starting at the extension's root, like this:
/path/to/script.js
When querying tabs by URL
tabs.query()
:
"tabs"
permission.
"tabs"
permission, but only tabs whose URLs match the extension's host permissions will be included in the results.
When calling
tabs.remove()
:
tabs.remove()
promise is fulfilled after the
beforeunload
事件。
beforeunload
.
http:
or
https:
方案。
activeTab
permission does not allow intercepting network requests in the current tab. (See
bug 1617479
)
webRequest.onAuthRequired
for proxy authorization. See the documentation for
webRequest.onAuthRequired
.
manifest.json
file must contain a
web_accessible_resources
key with the URL of the extension page.
注意： 任何 website may then link or redirect to that URL, and extensions should treat any input (POST data, for example) as if it came from an untrusted source, just as a normal web page should.
browser.webRequest.*
APIs allow returning Promises that resolves
webRequest.BlockingResponse
asynchronously.
webRequest.onAuthRequired
supports asynchronous
webRequest.BlockingResponse
via supplying
'asyncBlocking'
.
onFocusChanged
的
windows
API, will trigger multiple times for a given focus change.
declarativeContent.RequestContentScript
API (which is rarely used, and is unavailable in stable releases of Chrome).
moz-extension://«random-UUID»/«path»
. This randomness can prevent you from doing a few things, such as add your specific extension's URL to another domain's CSP policy.
web_accessible_resources
, it is accessible as
chrome-extension://«your-extension-id»/«path»
. The extension ID is fixed for a given extension.
web_accessible_resources
, this property is unsupported.
"key"
property
to pin the extension ID across different machines. This is mainly useful when working with
web_accessible_resources
.
fetch()
) to a relative URL (like
/api
), it will be sent to
https://example.com/api
.
this.{variableName}
in one script and then attempting to access them using
window.{variableName}
in another. This is a limitation created by the sandbox environment in Firefox. This limitation may be removed, see
bug 1208775
.
window.prop1 = "prop"
and the user then navigates away and returns to the page
window.prop1
is undefined. This issue is tracked in
bug 1525400
.
To mimic the behavior of Chrome, listen for the
pageshow
and
pagehide
events. Then simulate the injection or destruction of the content script.
The main
manifest.json
page includes a table describing browser support for
manifest.json
keys. Where there are caveats around support for a given key, this is indicated in the table with an asterisk "*" and in the reference page for the key, the caveats are explained.
These tables are generated from compatibility data stored as JSON files in GitHub .
On Linux and Mac:
Chrome passes one argument to the native app, which is the origin of the extension that started it, in the form:
chrome-extension://«extensionID/»
(trailing slash required). This enables the app to identify the extension.
在 Windows： Chrome passes two arguments:
allowed_extensions
.
allowed_origins
代替。
Some extension APIs allow an extension to send data from one part of the extension to another, such as
runtime.sendMessage()
,
tabs.sendMessage()
,
runtime.onMessage
，
postMessage()
方法为
runtime.port
，和
tabs.executeScript()
.
The Structured clone algorithm supports more types than the JSON serialization algorithm. A notable exception are (DOM) objects with a
toJSON
method. DOM objects are not cloneable nor JSON-serializable by default, but with a
toJSON()
method, these can be JSON-serialized (but still not cloned with the structured cloning algorithm). Examples of JSON-serializable objects that are not structured cloneable include instances of
URL
and
PerformanceEntry
.
Extension that rely on the
toJSON()
method of the JSON serialization algorithm can use
JSON.stringify()
followed by
JSON.parse()
to ensure that a message can be exchanged, because a parsed JSON value is always structurally cloneable.
最后修改： , 由 MDN 贡献者