Plugin: mozprefs

This file explains how Firefox preferences can be manipulated at run-time using Elektra’s intercept open and a custom autoconfig script.

Basics

kdb configure-firefox -s will configure everything needed to get started.

Files

• /usr/lib/firefox / /usr/lib/firefox-esr
  • defaults/pref/autoconfig.js Loads elektra.cfg

 ```
 pref("general.config.filename", "elektra.cfg");
 pref("general.config.obscure_value", 0);
```

• elektra.cfg Contains the autoconfig code

~/.mozilla/firefox/<profile>/prefs.js Contains the user preferences. The configure-firefox script will append the config for our autoconfig script:

user_pref("elektra.config.file", "/tmp/imnotreal.js");
user_pref("elektra.config.reload_trigger_port", 65432);

Every time the string reload is send to localhost:elektra.config.reload_trigger_port the autoconfig script will import the preferences from elektra.config.file
elektry.config.file contains the name of the dummy file for intercept open. open calls to this file will be intercepted and the content generated by intercept open

Setting preferences

Guided setup

Running kdb configure-firefox -a provides a guided setup for adding http_proxy and homepage preferences.

% kdb configure-firefox -a
Add new preferences
Config Setup:

1) Proxy
2) Homepage
0) Exit
1

Setting up HTTP Proxy
1) lock
2) default
3) user
0) Exit
1

Proxy Type
0) No Proxy
1) Manual Setup
2) PAC
4) Auto-detect
5) System Settings
1

Set string to 1
Host/IP: 127.0.0.1
Port: 8080
Setting lockPref HTTP Proxy to 127.0.0.1:8080

Manual setup

This example shows how to manually setup a preferences. It's equivalent to the example shown above in the Guided setup

kdb setmeta user/prefs/lock/network/proxy/type type integer
kdb set user/prefs/lock/network/proxy/type 1
kdb setmeta user/prefs/lock/network/proxy/http type string
kdb set user/prefs/lock/network/proxy/http 127.0.0.1
kdb setmeta user/prefs/lock/network/proxy/http_port type integer
kdb set user/prefs/lock/network/proxy/http_port 8080

Test Setup

Running kdb configure-firefox -t will set up some test values.

% kdb export /preload

[open]
\/tmp\/imnotreal.js =
\/tmp\/imnotreal.js/generate = user/prefs
\/tmp\/imnotreal.js/generate/plugin = mozprefs


% kdb export user/prefs

[lock/a/lock]
1 = lock1
2 = lock2
[pref/a/default]
1 = 1
2 = 2
[user/a/user]
f = false
t = true

% kdb export user/prefs mozprefs

lockPref("a.lock.1", "lock1");
lockPref("a.lock.2", "lock2");
pref("a.default.1", 1);
pref("a.default.2", 2);
user_pref("a.user.f", false);
user_pref("a.user.t", true);

% kdb elektrify-open firefox-esr "about:config"

% kdb setmeta user/prefs/lock/a/lock/3 type boolean
% kdb set user/prefs/lock/a/lock/3 true
% kdb export user/prefs

[lock/a/lock]
1 = lock1
2 = lock2
3 = true
[pref/a/default]
1 = 1
2 = 2
[user/a/user]
f = false
t = true

Limitations

Changing locked values doesn't work without restarting.