The files in this repository create a toolkit to load arbitrary javascript files to be run in Firefox browser context. This method relies on autoconfig functionality available in Firefox.
Files in program folder tell Firefox to load an additional javascript module file from the current Profile directory. The boot.sys.mjs is the one that implements loading and managing additional files.
Since the files in program go to the main program installation path, they will affect all profiles that are being run using that executable.
However, the bulk of the logic is located in profile folder with boot.sys.mjs so if the file is not found there then the loader is simply not used.
The loader module (boot.sys.mjs) depends on two additional files: utils.sys.mjs to which is collection of various helper functions you can use in your scripts and fs.sys.mjs to implement read and write operations on the file system. Version "0.10.0" also added new uc_api.sys.mjs file which as an interface that scripts should import instead of importing utils.sys.mjs directly.
Note as of version "0.8" fx-autoconfig is incompatible with Firefox ESR 102
Note version "0.10.0" deprecated old _ucUtils symbol in favor of new UC_API so expect breakage if upgrading from older versions.
Please note that malicious external programs can now inject custom logic to Firefox even without elevated privileges just by modifying boot.sys.mjs or adding their own script files.
Copy the contents of the directory called "program" (not the directory itself) into the directory of the Firefox binary you want it to apply to.
This means that if you want to affect multiple installations, like release, beta, ESR etc. you need to add the files to all of them.
! Note for non-regular Firefox installs: Compatibility issues will arise if your Firefox install is already using autoconfiguration files (such as Librefox). In these situations the easiest route might be to merge the contents of config.js with the autoconfiguration file your install has. This may or may not require you to also set prefs from <program>/defaults/pref/config-prefs.js with the excetion of general.config.filename.
Windows
Firefox is typically installed to C:\Program Files\Mozilla Firefox\
Copy defaults/ and config.js there from the program folder. config.js should end up in the same directory where firefox.exe is.
Linux
Firefox is typically installed to /usr/lib/firefox/ or /usr/lib64/firefox/
Copy defaults/ and config.js there from the program folder. config.js should end up in the same directory where firefox binary is.
MacOS
Firefox is typically installed to /Applications/Firefox.app/Contents/MacOS/ or /Applications/Firefox Nightly.app/Contents/MacOS/
Copy defaults/ and config.js to /Applications/Firefox.app/Contents/Resources/ from the program folder. config.js should end up in the /Applications/Firefox.app/Contents/Resources/ directory.
Nix
NixOS:
programs.firefox = {
enable = true;
autoConfig = builtins.readFile(builtins.fetchurl {
url = "https://raw.githubusercontent.com/MrOtherGuy/fx-autoconfig/master/program/config.js";
sha256 = "1mx679fbc4d9x4bnqajqx5a95y1lfasvf90pbqkh9sm3ch945p40";
});
};Home Manager:
home.packages = with pkgs; [
(firefox.override {
extraPrefsFiles = [(builtins.fetchurl {
url = "https://raw.githubusercontent.com/MrOtherGuy/fx-autoconfig/master/program/config.js";
sha256 = "1mx679fbc4d9x4bnqajqx5a95y1lfasvf90pbqkh9sm3ch945p40";
})];
})
];Copy the contents of the folder "profile" (not the folder itself) to the Firefox profile folder that you want to modify. If the profile already has a chrome folder (for userChrome.css or userContent.css) then the chrome folders should merge. Otherwise the chrome folder will be created.
You should end up with chrome folder in the profile root, and three folders inside it - JS, resources and utils.
There will be four files in the chrome/utils/ folder:
chrome.manifest- registers file paths to chrome:// protocolboot.sys.mjs- implements user-script loading logicfs.jsm- implements filesystem-related functions -boot.sys.mjsuses this file internally.utils.sys.mjs- implements various functions used byutils.sys.mjsand which your scripts can also use- (new in 0.10.0)
uc_api.sys.mjs- helper API, making importing methods fromutils.sys.mjseasier
Firefox caches some files to speed-up startup. But the files in utils/ modify the startup behavior so you might be required to clear the startup-cache.
If you modify boot.sys.mjs and happen to break it, you will likely need to clear startup-cache again.
Clear startup-cache via about:support (recommended)
- Load
about:support - In the top-right corner should be a button to clear the startup-cache.
- Click that button and confirm the popup that will show up.
- Firefox will restart with startup-cache cleared, and now the scripts should be working.
Clear startup-cache manually
The startup-cache folder can be found as follows:- load the following url
about:profiles - locate the profile you wish to set up and click the "Open Folder" of the Local directory - this should open the directory in File Manager
- Close Firefox
- Delete folder "StartupCache"
- Run Firefox
(Note) If you wish to set up a profile that doesn't use normal profile directories (i.e one that was lauched with command-line such as firefox.exe -profile "C:\test\testprofile" or with portable-apps launcher) then the startupCache folder will be in the profile root folder.
The loader module boot.sys.mjs looks for three kinds of files in your scripts directory ("JS" by default - can be changed in chrome.manifest):
<filename>.uc.js- classic script which will be synchronously injected into target documents.<filename>.uc.mjs(new in 0.8) - script which will be loaded into target documents asynchronously as ES6 module.<filename>.sys.mjs- module script which will be loaded into global context synchronously once on startup
Additionally (".uc.js") scripts can be marked as background-module by tagging them with @backgroundmodule in the script header. (Deprecated in 0.10.0)
Just put any such files into the JS directory. The JS directory should be in the same directory where userChrome.css would be. If you wish to change the directory name then you need to modify the chrome.manifest file inside utils directory. For example change ../JS/ to ../scripts/ to make Firefox load scripts from "scripts" folder.
At runtime, individual scripts can be toggled on/off from menubar -> tools -> userScripts. Note that toggling requires Firefox to be restarted, for which a "restart now" -button is provided. The button clears startup-cache so you don't need to worry about that.
For window scoped scripts (classic .uc.js and .uc.mjs) it the toggling should take effect when a new window is opened. Any effects in the old window will persist though.
A global preference to toggle all scripts is userChromeJS.enabled. This will disable all scripts but leaves the restart-button in the custom menu available.
From version 0.8.5 onwards the loader also supports injection of styles. The default directory where loader looks for them is chrome/CSS/ which again can be re-mapped by modifying chrome/utils/chrome.manifest
File name of styles must end with .uc.css which the loader will pick up automatically - just like scripts. By default, scripts are injected in author mode only into browser.xhtml - you can register other targets using the header @include directives just like scripts.
Alternatively you can use @stylemode agent_sheet directive in header to make loader register it as agent style. User styles are not supported currently - just use userChrome.css for that.
Notice that the header format for styles is slightly different than it is for scripts because CSS doesn't support // line comments.
Script files (among other things) are loaded using chrome:// protocol. Chrome urls are of form:
chrome://<package>/<provider>/<path>
eg.
chrome://userscripts/content/my_script.uc.js
Notable for the path part, it must start with [a-zA-Z0-9] and as such the loader module only tries to seek script files where the filename starts with alphanumeric character. Note that files in sub-directories can still start with some other character.
Same limitation also applies to all other uses of chrome:// urls, such as if you try to load some file from your resources
directory using chrome url.
See more about chrome url canonification at searchfox
This manager is NOT entirely compatible with all existing userScripts - specifically scripts that expect a global _uc object or something similar to be available. This manager does export a _ucUtils object to window objects which is described in api definition section.
Additionally, version 0.10.0 is very much incompatible with earlier versions, because _ucUtils is replaced with UC_API.
Each script normally runs once per document when the document is loaded. A window is a document, but a window may contain several "sub-documents" - kind of like iframes on web pages, an example of this is the sidebar.
By default, the loader executes your script only in the main browser window document. Using any @include header will override the default - for example:
// ==UserScript==
// @include chrome://browser/content/places/places.xhtml
// ==/UserScript==The above would be executed only in the Library window.
// ==UserScript==
// @include main
// @include chrome://browser/content/places/places.xhtml
// ==/UserScript==This would execute in both library and main window. main is an alias for chrome://browser/content/browser.xhtml in Firefox and chrome://messenger/content/messenger.xhtml in Thunderbird
A wildcard * can be used to target any window.
// ==UserScript==
// @include *
// @exclude main
// ==/UserScript==This would execute in all documents, excecpt main window - notice "main" is excluded this time.
In addition, scripts can be marked as @backgroundmodule in which case they are executed "outside" of any document when the the loader reads the file. See backgroundmodule section below.
Some convenience functions are provided for scripts to use in global _ucUtils object available in windows.
(Deprecated in 0.10.0) - use ES6 modules (.sys.mjs files) instead.
Scripts can be marked as background modules by including a @backgroundmodule line in script header. See example:
// ==UserScript==
// @name example background module
// @note Loading as background module
// @backgroundmodule
// ==/UserScript==
let EXPORTED_SYMBOLS = [];
...
// actual script hereAlternatively, you can name your script with .sys.mjs file extension in which case the loader automatically treats it as backgroundmodule.
Note that the EXPORTED_SYMBOLS array like above in module global scope is mandatory in .uc.js scripts when they are loaded as backgroundmodule. It is not necessary in .sys.mjs scripts.
// ==UserScript==
// @name example sys.mjs module
// ==/UserScript==
import { Some } from "chrome://userscripts/content/modules/some.sys.mjs";
// This would import the script from "modules" sub-directory of your scripts folder.
// Note that such script would not be loaded by boot.jsm itself.
Some.doThing();
...The manager loads any .sys.mjs files always as backgroundmodule - in addition they are loaded as ES6 modules which means you can use static import and export declarations inside them.
You should note that background modules do not have access to window objects when they are being run because they are executed before any window exists. Thus, they also do not automatically get access to _ucUtils or UC_API objects.
As of version 0.8 ES6 module scripts, including backgroundmodules (so .sys.mjs and .uc.mjs files) can import UC_API like this:
import * from "chrome://userchromejs/content/uc_api.sys.mjs";Although window scoped module scripts (.uc.mjs) automatically gain access to it anyway from the window object.
(This section only applies to pre 0.10.0 versions and somewhat if you try to import utils.sys.mjs directly)
Note for .uc.mjs scripts!
Because your script is running in its own module scope within a window the module imported with an import statement above is NOT the same instance of the object as what you would get automatically via _ucUtils. The methods within are the same, but since it is a different object its internal properties have not been initialized by boot.sys.mjs so some functionality is missing - such as access to custom script info via .getScriptData()
You can instead use ChromeUtils to import the same object from the global object:
const { _ucUtils } = ChromeUtils.importESModule("chrome://userchromejs/content/utils.sys.mjs")Or indeed just use _ucUtils from the window object.
The same behavior applies to all modules imported from .uc.mjs module scopes via import statements.
The @description header can be used to store short description in script meta-data.
// ==UserScript==
// @description simple test script that does nothing
// ==/UserScript==Normally @description stores the text appearing on the same line as the header itself. However, when @long-description is present the description will be a block comment starting from the next line after the @description header:
// ==UserScript==
// @long-description
// @description this-part-is-now-ignored
/*
Here goes my long description about this mighty powerful script.
It does all the things and even more!
...
or at least that's the plan, it actually does nothing currently :p
*/
// ==/UserScript==Note that the single-line part of @description is now ignored. But you can put something there as fallback value for loaders that don't have multi-line description support.
This header can be used to mark scripts that should not be put into startup-cache. Instead, such scripts are always read from disk when loaded.
// ==UserScript==
// @name example ignorecache file
// @ignorecache
// ==/UserScript==
console.log("Hello world!")This script would log "Hello world!" to console when new window is opened. Normally if you would change this script content and then open a new window, then Firefox would still log "Hello world!" because the script is cached.
However, by ignoring cache the file is loaded from disk every time its used, thus changes will be reflected immediately (but not for the window the script has already been loaded into).
This header may be useful while developing a script, but you should leave caching enabled most of the time.
Note: if your script has already been cached once, then you need to clear startup-cache once to make it ignore cache. In other words, you can't add this header to existing script to make it ignore cache immediately.
// ==UserScript==
// @name example
// @loadOrder 3
// ==/UserScript==
console.log("This script is loaded sooner than default")Load-order is treated as positive integer (including 0)
By default scripts have load-order 10. Scripts with load-order <10 are injected before unmarked scripts and >10 are loaded after them.
If load-order is not specified then scripts follow normal filename alphabetical ordering.
Note: All Scripts marked as backgroundmodule will have load-order -1
By default the script is executed once per document it applies to, but this can be changed with @onlyonce header in which case the script will only be run in the first document.
// ==UserScript==
// @name example only-once file
// @onlyonce
// ==/UserScript==
console.log("Hello world!") // This is only run in the first window that opens.(Deprecated in 0.10.0) - use Windows.onCreated instead
Scripts can define a function to be executed when they are loaded in the header portion of the script. Consider the following header:
// ==UserScript==
// @name My Test Script
// @onlyonce
// @startup myScriptObject
This tells the loader to execute this script file only once per session because of @onlyonce directive. But the header also tells the loader to execute a special function named _startup from sharedGlobal.myScriptObject on each window. This makes it possible to do some global initialization work once and then run only the _startup function for each window created afterwards.
The _startup function will receive one argument - reference to the window object where it was executed.
In short, to use startup directive you need to store an object named myScriptObject to the sharedGlobal object and the myScriptObject must have a property called _startup.
_ucUtils.sharedGlobal.myScriptObject = {
_startup: function(win){ console.log(win.location) }
}NOTE This is behavior is completely incompatible with the way old userscripts implement startup - which generally was of form eval(<whatever_is_in_header_startup>)
Default value is author_sheet - valid values are author_sheet and agent_sheet
/* ==UserScript==
// @name agent style sheet
// @description an example for @stylemode directive
// @stylemode agent_sheet
// ==/UserScript== */Tells the loader in which mode this style should be injected. Agent sheets are global, author sheets are per document you inject them into (default browser.xhtml)
Tells the loader to register this style using its file:/// url instead of chrome:// url.
/* ==UserScript== // @name author style sheet // @usefileuri // ==/UserScript== */
Note that some CSS features may not be available for file:// uri styles. However, chrome:// styles cannot be modified using devtools, while file:// uri styles can be.
For pre 0.10.0 definitions you can check separate file available at uc_utils_old.md.
TypeScript types available as a private npm package in the types directory.
Helpers are available as a namespace object - the whole namespace can be imported to module scripts as follows:
import * from "chrome://userchromejs/content/uc_api.sys.mjs";The same namespace is also defined on window objects as UC_API symbol that can be used in window scoped scripts.
Or you can import individual namespaces like this:
import FileSystem from "chrome://userchromejs/content/uc_api.sys.mjs";Helpers divided into separate namespaces:
- UC_API.FileSystem
- UC_API.Hotkeys
- UC_API.Notifications
- UC_API.Prefs
- UC_API.Runtime
- UC_API.Scripts
- UC_API.SharedStorage
- UC_API.Utils
- UC_API.Windows
Scripts should generally use the resources folder for their files. The helper functions interacting with filesystem expect resources to be the root folder for script operations.
The resources folder is registered to chrome:// scheme so scripts and stylesheets can use the following URL to access files within it:
"chrome://userChrome/content/<filename>.txt"
Scripts folder is registered to: chrome://userScripts/content/
The loader module folder is registered to chrome://userchromejs/content/
Main idea is that various methods of the FileSystem namespace return a FileSystemResult object instead of the actual operation result directly.
The FileSystemResult result object is one of four types:
Filesystem.RESULT_FILEget reference to a fileFilesystem.RESULT_DIRECTORYget referece to a directoryFilesystem.RESULT_ERRORnon-existent file or other kind of errorFilesystem.RESULT_CONTENTfile read operation results
The result object has various methods to access underlying data.
// return nsIFile object representing either a file a directory
// throws if called on CONTENT or ERROR types
fsResult.entry()
// return the file text content as string
// throws if called on anything except CONTENT type
fsResult.content() // returns content that was read
// return an iterator over files in a directory
// Note, the individual entries are nsIFile objects, not wrapped `FileSystemResult`s
// throws when called on anything except DIRECTORY type
fsResult.entries()
// entries() is called internally if you try to iterate over the result:
fsResult = FileSystem.getEntry("my_dir");
for(let file of fsResult){
...
}
// size of read content or size of the file on disk
fsResult.size
// Read the content of this FileSystemResult
// throws if called on non-FILE type
let content = await fsResult.read() // Async read
console.log(content);
<< "Hello world!"
// throws if called on non-FILE type
let sync_content = fsResult.readSync();
console.log(content);
<< "Hello world!"
// get a file URI for this result
console.log(fsResult.fileURI)
<< file:///c:/temp/things/some.txt
// Tries to open a given file entry path in OS file manager.
// Returns true or false indicating success.
// Whether this works or not probably depends on your OS.
// Only tested on Windows 10.
fsResult.showInFileManager()let fsResult = UC_API.FileSystem.getEntry("some.txt");
result.isFile()
// true
let nonexistent = UC_API.FileSystem.getEntry("nonexistent.txt");
nonexistent.isError()
// true
let dir = UC_API.FileSystem.getEntry("directory");
dir.isDirectory()
// trueAsynchronously read a file. Throws if the argument is not a string
let fsResult = await UC_API.FileSystem.readFile("some.txt");
fsResult.isFile()
// false
fsResult.isContent()
// true
console.log(fsResult.content())
// "Hello world!"Synchronously read a file. The argument can be either a string representing filename or referece to a nsIFile object.
let fsResult = UC_API.FileSystem.readFileSync("some.txt");
fsResult.isContent()
// true
console.log(fsResult.content())
// "Hello world!"Asynchronously try to read a file and parse it as json. If file can't be parsed then returns null.
let fsResult = await UC_API.FileSystem.readJSON("some.json")let some_content = "Hello world!\n";
let bytes = await UC_API.FileSystem.writeFile( "hello.txt", some_content );
console.log(bytes);
<< 13Write the content into file as UTF8. On successful write the promise is resolved with number of written bytes.
By default writing files using this API is only allowed in resources directory. Calling writeFile with fileName like "../test.txt" will then reject the promise. You must set pref userChromeJS.allowUnsafeWrites to true to allow writing outside of resources.
Note! Currently this method replaces the existing file if one exists.
The optional options argument is currently only used to pass a filename for temp file. By default it is derived from fileName.
Returns FileSystemResult with type DIRECTORY for the profile chrome directory
let fsResult = UC_API.FileSystem.chromeDir();
let uri = fsResult.fileURI // a file:/// uri
for (let file of fsResult){ // equal to fsResult.entries()
console.log(file.leafName);
}// description for hotkey Ctrl + Shift + G
let details = {
id: "myHotkey",
modifiers: "ctrl shift",
key: "G",
command: (window,commandEvent) => console.log("Hello from " + window.document.title);
}
let myKey = UC_API.Hotkeys.define(details);
// myKey will be a instance of Hotkey description object If command is a function then a new <command> element will be created for it with an id attribute derived from the specified id. If command is a string then the hotkey will simply invoke a command matching that string - either a built-in command name or an id of the to-be-invoked .
hotkeys.define() simply creates a definition for the hotkey, but it does not add it to any window. The Hotkey instance will have methods you can use to do that:
{
trigger: Object - description for to-be-generated <key> element
command: Object - description for to-be-generated <command> element
matchingSelector: string
attachToWindow(window,opt) - creates a <key> and <command> elements to specified window
autoAttach(opt) - adds hotkey to all current (main) windows as well as all newly created ones
suppressOriginalKey(window) - Disables the original `<key>` for this hotkey
restoreOriginalKey(window) - Re-enables the original `<key>` if it was disabled
}
The optional opt object on attachToWindow(_,opt) and autoAttach(opt) is a simple dictionary which can be used to run suppressOriginalKey() automatically:
Note: attachToWindow() is asynchronous method - this is so that we don't add the elements to DOM during window creation, but only after it is ready.
let details = {
id: "myHotkey",
modifiers: "ctrl",
key: "T",
command: (window,commandEvent) => console.log("Hello from " + window.document.title);
}
UC_API.Hotkeys.define(details).autoAttach({suppressOriginalKey: true});
// This defines the key `Ctrl+T`, attaches it to all current and future main browser windows and disables original newtab key.Display and receive input to and from browser notification toolbar (not to be confused with OS notification system)
_ucUtils.showNotification(
{
label : "Message content", // text shown in the notification
type : "something", // opt identifier for this notification
priority: "info", // opt one of ["system","critical","warning","info"]
window: window.top , // opt reference to a chromeWindow
tab: gBrowser.selectedTab, // opt reference to a tab
buttons: [...], // opt array of button descriptors
callback: () => {} // opt function to be called when notification is dismissed
}
)Priority defines the ordering and coloring of this notification. Notifications of higher priority are shown before those of lower priority. Priority defaults to "info".
If window key exists then the notification will be shown in that window. Otherwise it is shown in the last active window.
If tab key exists then the notification will be shown in that tab only. Otherwise the notification is global to the window.
See more about buttons and callback keys at notificationbox.js
A shortcut for reading and writing preferences
UC_API.Prefs.set("some.pref.path","test");
UC_API.Prefs.set("some.other.pref",300);This will throw if you try to set a pref to a value of different type than what it currently is (ie. boolean vs. string) unless the pref doesn't exist when this is called.
This will also throw if you try to set the pref with value that is not one of number, string, boolean - number is also converted to integer.
Returns a representation of the pref wrapped into an object with properties:
let myPref = UC_API.Prefs.get("userChrome.scripts.disabled");
/*
* {
* exists() // true|false indicating if this pref exists
* name // string - the called pref name
* value // <number|string|boolean> | `null` - null means pref with this name could not be read
* set value() // same as _ucUtils.prefs.set(name,value)
* hasUserValue() // true|false indicating if this has user set value
* type // "string"|"boolean"|"number"|"invalid"
* reset() // resets this pref to its default value
* }
*/
myPref.exists()
// false - "userChrome.scripts.disabled" does not existlet callback = (value,pref) => (console.log(`${pref} changed to ${value}`))
let prefListener = UC_API.Prefs.addListener("userChromeJS",callback);Note that the callback will be invoked when any pref that starts with userChromeJS is changed. The pref in callback argument will be a Pref object wrapping the value of the actual pref whose value was changed.
UC_API.Prefs.removeListener(prefListener) // from above example
Pref class can also be imported directly to module scripts like this:
import { Pref } from "chrome://userchromejs/content/utils.sys.mjs";Provides general information about the loader and state of the browser.
One of "Firefox" or "Thunderbird"
Brand name of the browser eg. "Firefox", "Firefox Nightly" etc.
Perhaps to be used in the future
The version string of boot.sys.mjs
Immediately restart the browser. If the boolean clearCache is true then Firefox will invalidate startupCache which allows changes to the enabled scripts to take effect. A closing prompt is shown if some other part of the browser such as a website would need a confirmation about restart.
UC_API.Runtime.startupFinished()
.then(()=>{
console.log("startup done");
});Returns a promise that will be resolved when all windows have been restored during session startup. If all windows have already been restored at the time of calling the promise will be resolved immediately.
Provide information about registered scripts and styles and some controls for them.
Returns ScriptInfo object(s) with a copy of their metadata. This includes scripts that are not yet running or which are disabled by pref.
When called without arguments returns an array of ScriptInfo objects describing your scripts.
let scripts = UC_API.Scripts.getScriptData();
for(let script of scripts){
console.log(`${script.filename} - @{script.isEnabled} - ${script.isRunning}`)
}If the first argument is a string then this returns a single ScriptInfo object for a script that had the specified filename. If such script is not found then null is returned.
let script = UC_API.Scripts.getScriptData("my-script.uc.js");
console.log(`@{script.name} - ${script.isRunning}`);If the first argument is a function, then this function returns a filtered list of scripts that return true when the function is run on them:
let scripts = UC_API.Scripts.getScriptData(s => s.isRunning);
console.log(`You have ${scripts.length} running scripts);
// This is essentially the same as UC_API.Scripts.getScriptData().filter(s => s.isRunning)Note! If the first argument is anything other than a function or a string, then getScriptData() will throw an error.
Mechanically exactly the same as getScriptData() but returns styles instead of scripts.
Returns the <menu> element created for controlling scripts. In Firefox this is inside Menubar > Tools.
Note! The menu is lazily generated and calling this method should cause it to be generated if it isn't already.
UC_API.Scripts.openScriptDir();Tries to open your script directory in OS file manager. Returns true or false indicating success. Whether this works or not probably depends on your OS. Only tested on Windows 10.
UC_API.Scripts.openStyleDir();Tries to open your style directory in OS file manager. Returns true or false indicating success. Whether this works or not probably depends on your OS. Only tested on Windows 10.
This can be used to construct a ScriptInfo object from arbitrary string following the same logic the loader uses internally. When given aName as "filename" the aString is parsed just like script metadata block in your files. optional parseAsStyle argument, when truthy, makes the method parse aString as style instead of a script.
let myMetadataBlock = `// ==UserScript==
// @name my-test-info
// @description Constructed ScriptInfo
// ==/UserScript==
`;
let scriptInfo = UC_API.Scripts.parseStringAsScriptInfo("fakeFileName", myMetadataBlock);
console.log(scriptInfo.name, scriptInfo.chromeURI);
// "my-test-info chrome://userscripts/content/fakeFileName"
let styleInfo = UC_API.Scripts.parseStringAsScriptInfo("fakeFileName", myMetadataBlock, true);
console.log(styleInfo.name, styleInfo.chromeURI);
// "my-test-info chrome://userstyles/skin/fakeFileName"Note! There needs to be a new-line after the closing // ==/UserScript== "tag" for the metadata to be parsed correctly.
filename:
UC_API.Scripts.toggleScript("test.uc.js")Element where this is a menuitem:
UC_API.Scripts.toggleScript(this);If the argument is an element the function reads a filename attribute from the element and uses that. Toggles the specified script, note that browser restart is required for changes to take effect.
The return value is null if a matching script was not found. Otherwise, the return value is an object { script: filename, enabled: true|false }
UC_API.Scripts.updateStyleSheet() // reloads userChrome.css
// reloads a style in author-mode stylesheets list with matching name
UC_API.Scripts.updateStyleSheet("userChrome.au.css","author")
// reloads a style in agent-mode stylesheets list with matching name
UC_API.Scripts.updateStyleSheet("userChrome.ag.css","agent")Argument filename is relative to resources folder, but you can use ../ prefix to get back to chrome folder.
Note, you can't reload a style that is in one sheet-mode list into another sheet-mode. Such as, you cannot use this to reload userChrome.css into agent-mode list.
Return value true/false indicates wheter a style file with specified name was found in the corresponding list.
If the specified stylesheet imports other files, then calling this will also reload any of those imported files. However, in experience it might be that reload of imported stylesheets does not take effect until a new window is created.
Few DOM manipulation helpers for creating elements etc.
UC_API.Utils.createElement(document,"menuitem",{ id:"someid", class:"aClass", label:"some label" })Attaches a new element with tagname to the given document and adds it attributes from attributes object. isHTML is a boolean indicating whether the element is XUL element or HTML element - defaults to false.
UC_API.Utils.createWidget({
id: "funk-item", // required
type: "toolbaritem", // ["toolbaritem","toolbarbutton"]
label: "funky2", // opt (uses id when missing)
tooltip: "noiseButton", // opt (uses id when missing)
class: "noiseButton", // opt additional className (see below for more)
image: "favicon.png", // opt image filename from resources folder
style: "width:30px;", // opt additional css-text (see below for more)
allEvents: true, // opt trigger on all clicks (default false)
callback: function(ev,win){ // Function to be called when the item is clicked
console.log(ev.target.id)
}
})Note: Any keys in the details object that are not mentioned above are added to the created element as attributes.
Widget is a wrapper for actual elements. Firefox tracks widget placements across windows meaning that you can create the widget once and then you can re-position it using customize mode and its new location will be shared in all windows. The wrapper contains information about the instances of that widget in windows.
The class of elements using this will by default be "toolbarbutton-1 chromeclass-toolbar-additional" and the value of the class property (when provided) will be added into that.
The style info will be added as inline style to all elements of that widget. The image will be loaded as centered background-image in toolbaritems and as list-style-image in toolbarbuttons.
The callback function will be stored in _ucUtils.sharedGlobal mapped to the provided id. Clicking the button will call the callback which will receive two arguments: event (click) and window which is a reference to the window object where that instance of the widget is.
If the callback property is not a function, then the widget will be just a passive element.
The allEvents property defines if the callback should be called for all clicks, not just left-clicks.
The image is loaded from resources folder so save your icon files there.
This method will throw if:
idis not providedtypeis anything except"toolbaritem"or"toolbarbutton"- A widget with same id already exists. For example if a script which calls this method is executed in multiple Firefox windows then the first one should succeed, but successive calls should throw an Error.
Escapes xul markup in case you need to add strings to the UI
UC_API.Utils.loadURI(window,{
url:"about:config",
where:"tab", // one of ["current","tab","tabshifted","window"]
private: true, // should the window be private
userContextId: 2 // numeric identifier for container
});
// "tabshifted" means background tab but it does not work for unknown reasons
// Private tabs cannot be created in non-private windowsReturn a boolean indicating if the operation was successful. "url" and "where" properties are mandatory - others are optional.
If scripts need to store information to a global object they can get reference to that as follows:
let global = UC_API.SharedStorageNote that data stored here is only available in memory and does not persist on disk.
Namespace to interact with windows.
Return a list of handles for each window object for this firefox instance. If onlyBrowsers is true then this only includes browser windows. If it's false then it also includes consoles, PiP, non-native notifications etc.
let allMyWindows = UC_API.Windows.getAll(false)onlyBrowsers defaults to true.
UC_API.Windows.forEach((document,window) => console.log(document.location), false)Runs the specified function for each window. The function will be given two arguments - reference to the document of the window and reference to the window object itself.
Note! UC_API may not be available on all target window objects if onlyBrowsers is false. The callback function should check for it's availability when called that way.
Returns the last focused window. If windowType is undefined then returns "navigator:browser" window (eg. main browser window) on Firefox or "mail:3pane" window on Thunderbird.
Returns true/false indicating if the argument window is a main browser window.
Registers the callback function to be called when a new window has been opened. The callback is executed on DOMContentLoaded event. Perhaps not useful for normal scripts, but can be an easy way for a background-script to do work when window is created.
Note! This also works as replacement in version 0.10.0 for now deprecated @startup directive.
// ==UserScript==
// @name initialization script
// @description my filename is background.uc.mjs
// @onlyonce
// ==/UserScript==
import { Windows, Hotkeys } from "chrome://userchromejs/content/uc_api.sys.mjs";
let counter = 0;
Hotkeys.define({
id: "myHotkey",
modifiers: "ctrl shift",
key: "F",
command: () => console.log("Windows opened until now:", counter)
}).autoAttach(); // autoAttach causes this hotkey to be added to all new windows
Windows.onCreated(win => {
counter++
});Since the above script is marked as @onlyonce it is only injected into the first browser window to do initialization work (registering the hotkey). But the Windows.onCreated callback gets called whenever a new window is created so the counter get updated.
Returns a Promise which resolves when it has finished its initialization work. Scripts are normally injected on DOMContentLoaded event, but lots of initialization has not happened yet.
UC_API.Windows.waitWindowLoading(window)
.then(win => {
console.log(win.document.title + " has finished loading")
})Since scripts run per window, startupFinished will be resolved once in each window that called it when ALL those windows have been restored. But waitWindowLoading will be resolved whenever the particular window that calls it has started up.
Did you experience broken Firefox startup with message banner:
"fx-autoconfig: Startup is broken"Did it provide you with a button to "Enable workaround"? And after restart you got another banner message:
"fx-autoconfig: Something was broken in last startup"Clicking the button sent you here, right? So what is going on here? Fear not! Here's what's happening... probably.
In older versions of this loader script, boot.sys.mjs had a hack to make a Firefox internal gBrowser object available for your custom scripts. However, said hack is now disabled by default in latest versions of boot.sys.mjs.
So, if boot.sys.mjs detects that startup has been broken because gBrowser is not available, it will show said banner. Clicking the "Enable workaround"-button will tell boot.sys.mjs to set a pref userChromeJS.gBrowser_hack.enabled to true on next startup. You can always set that pref manually if you wish.
Note: there's is also related pref userChromeJS.gBrowser_hack.required which boot.sys.mjs uses to tell itself that startup was broken on last run. Neiter the .required or .enabled pref might not exist if the loader has not detected broken startup.
If you later want to disable the "gBrowser hack" then you need to set both userChromeJS.gBrowser_hack.enabled and userChromeJS.gBrowser_hack.required to false - or simply removing both prefs.
Somewhere in your custom scripts you are using gBrowser object which is not necessarily available at the time you are executing your script. Do note however, that you don't have to be using gBrowser directly in your script, it may happen as a side-effect of accessing some other internal object.
One notable example is if you try to access gURLBar - that will internally end up accessing gBrowser - which does not exist and that will break startup.
Think about when your script needs to run and you have some options:
-
Wait until windows have been restored before running functions that access gBrowser. One method for that would be:
UC_API.Runtime.startupFinished().then(myFunctionAccessinggBrowser)` -
Check in your function whether
gBrowseris available, and if not use_gBrowserinstead. -
Apply the original hack that was done by boot.jsm:
if(window._gBrowser){
window.gBrowser = window._gBrowser;
}Note that the second option does not work if gBrowser is accessed as a side-effect of using something else. For example, if you accessed gURLBar, then you might be able to (depending what you try to do) instead get reference to urlbar element and use that:
gURLBar.someproperty // old
document.getElementById("urlbar").someproperty // replacementOr you can simply set userChromeJS.gBrowser_hack.enabled to true
Very WIP
There are few simplistic tests inside the test_profile directory. To run them you need to launch Firefox with command-line arguments pointing Firefox to use the test_profile folder as a non-relative profile. That would go for example like this:
firefox -profile "C:/things/fx-autoconfig/test_profile"
Test results should be printed to browser console.