Developer Mode

The current Firefox OS permissions model precludes modification and installation of certified/internal apps, which makes some device APIs completely unavailable to Marketplace and web apps. Developer Mode (DM) allows the user to indicate that they would like to relax the permissions model and expose all device APIs to content, as well as setting a group of related preferences. This article provides a high-level overview.

Features

Once DM has been enabled on a device, the user receives the following benefits:

• Certified/internal apps can be installed from anywhere.
• All developer-related prefs and settings are enabled, such as certified app debugging, web components, etc.
• Apps can install add-ons for themselves using the "import-app" activity.

Certified apps can be installed

Normally, certified/internal apps must be shipped with a Firefox OS distribution. With DM enabled, any app with the certified type can be installed, and can request any certified permissions. Thus, all device API's are unlocked with DM enabled.

Developer prefs and settings enabled

As of this writing, the following preferences are set when DM is enabled:

• dom.apps.developer_mode: true
• devtools.debugger.forbid-certified-apps: false
• network.disable.ipc.security: true
• dom.webcomponents.enabled: true

This also sets the following settings:

• developer.menu.enabled: true

Add-on import activity

Apps can normally not install apps or add-ons without requesting the webapps-manage permission, which is available to certified/internal apps only. With DM enabled, apps can create add-ons for themselves using the "import-app" activity. The imported app must meet the following criteria:

• It must be an add-on.
• Its filter(s) must only match the app initiating the activity.

The following example demonstrates this:

var activity = new MozActivity({
  name: 'import-app',
  data: {
    blob: blob /* app blob */
  }
});

activity.onsuccess = function() {
  // The Settings app has imported the app blob.
};

activity.onerror = function(e) {
  // The Settings app failed to import the app for some reason.
};

Enabling and disabling

DM can be toggled using the Settings app, WebIDE, or an activity. All have the same net effect, but enabling it through WebIDE is the only method that doesn't require a factory reset.

Settings app

To enable or disable DM via the Settings app:

1. Open the Settings app.
2. If you see a "Developer" panel near the end, skip to #6.
3. Tap on the "Device Information" panel near the end.
4. Tap on the "More Information" panel.
5. Enable "Developer Menu."
6. Tap on "Factory Reset and Enable Full DevTools" near the end to toggle it.
7. Your device will reboot and go into recovery mode. It'll reboot again in a minute or so into Firefox OS with developer mode toggled.

WebIDE

To enable DM via WebIDE:

1. Open WebIDE.
2. Connect to your device using the "Select Runtime" menu.
3. Open "Runtime Info" from the device menu.
4. Look at "ADB is root." If there's a button next to it, press it. If it says "maybe", or "no", or anything like that, there's a problem. If it says "yes," it's already set, and you can skip to step 5.
   1. When WebIDE is disconnected from the device, reconnect it.
   2. Re-open the "Runtime Info" menu.
5. Look at "Unrestricted DevTools privileges." If there's a button next to it, press it. If not, it should say "yes." If it says "maybe", or "no", or anything like that, there's a problem.
6. Developer mode is now enabled.

Activity

The activity to dispatch to enable or disable developer mode is "full-developer-mode". Here is an example:

var activity = new MozActivity({
  name: 'configure',
  data: {
    target: 'device',
    section: 'full-developer-mode'
  }
});

This will take the user to the Settings app, where they will be prompted to toggle developer mode, with a lot of warnings about the consequences.