/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at
http://mozilla.org/MPL/2.0/. */
const { PREF_BOOL, PREF_INT, PREF_INVALID, PREF_STRING } = Ci.nsIPrefBranch;
export class Branch {
/**
* @param {string=} branch
* Preference subtree. Uses root tree given `null`.
*/
constructor(branch) {
this._branch = Services.prefs.getBranch(branch);
}
/**
* Gets value of `pref` in its known type.
*
* @param {string} pref
* Preference name.
* @param {*=} fallback
* Fallback value to return if `pref` does not exist.
*
* @returns {(string|boolean|number)}
* Value of `pref`, or the `fallback` value if `pref` does
* not exist.
*
* @throws {TypeError}
* If `pref` is not a recognised preference and no `fallback`
* value has been provided.
*/
get(pref, fallback = null) {
switch (this._branch.getPrefType(pref)) {
case PREF_STRING:
return this._branch.getStringPref(pref);
case PREF_BOOL:
return this._branch.getBoolPref(pref);
case PREF_INT:
return this._branch.getIntPref(pref);
case PREF_INVALID:
default:
if (fallback != null) {
return fallback;
}
throw new TypeError(`Unrecognised preference: ${pref}`);
}
}
/**
* Sets the value of `pref`.
*
* @param {string} pref
* Preference name.
* @param {(string|boolean|number)} value
* `pref`'s new value.
*
* @throws {TypeError}
* If `value` is not the correct type for `pref`.
*/
set(pref, value) {
let typ;
if (typeof value != "undefined" && value != null) {
typ = value.constructor.name;
}
switch (typ) {
case "String":
// Unicode compliant
return this._branch.setStringPref(pref, value);
case "Boolean":
return this._branch.setBoolPref(pref, value);
case "Number":
return this._branch.setIntPref(pref, value);
default:
throw new TypeError(`Illegal preference type value: ${typ}`);
}
}
}
/**
* Provides shortcuts for lazily getting and setting typed Marionette
* preferences.
*
* Some of Marionette's preferences are stored using primitive values
* that internally are represented by complex types.
*
* Because we cannot trust the input of many of these preferences,
* this class provides abstraction that lets us safely deal with
* potentially malformed input.
*
* A further complication is that we cannot rely on `Preferences.sys.mjs`
* in Marionette. See
https://bugzilla.mozilla.org/show_bug.cgi?id=1357517
* for further details.
*/
class MarionetteBranch extends Branch {
constructor(branch = "marionette.") {
super(branch);
}
/**
* The `marionette.debugging.clicktostart` preference delays
* server startup until a modal dialogue has been clicked to allow
* time for user to set breakpoints in the Browser Toolbox.
*
* @returns {boolean}
*/
get clickToStart() {
return this.get("debugging.clicktostart", false);
}
/**
* The `marionette.port` preference, detailing which port
* the TCP server should listen on.
*
* @returns {number}
*/
get port() {
return this.get("port", 2828);
}
set port(newPort) {
this.set("port", newPort);
}
}
/** Reads a JSON serialised blob stored in the environment. */
export class EnvironmentPrefs {
/**
* Reads the environment variable `key` and tries to parse it as
* JSON Object, then provides an iterator over its keys and values.
*
* If the environment variable is not set, this function returns empty.
*
* @param {string} key
* Environment variable.
*
* @returns {Iterable.<string, (string|boolean|number)>}
*/
static *from(key) {
if (!Services.env.exists(key)) {
return;
}
let prefs;
try {
prefs = JSON.parse(Services.env.get(key));
} catch (e) {
throw new TypeError(`Unable to parse prefs from ${key}`, e);
}
for (let prefName of Object.keys(prefs)) {
yield [prefName, prefs[prefName]];
}
}
}
// There is a future potential of exposing this as Marionette.prefs.port
// if we introduce a Marionette.sys.mjs module.
export const MarionettePrefs = new MarionetteBranch();
