Elektra: Plugin: mozprefs

Elektra 0.8.24

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.