Die WebIDE ist in Firexfox 34 und neuer verfügbar

Du kannst sie bereits in Firefox 33 aktivieren. Besuche hierzu about:config, gehe zur Einstellung devtools.webide.enabled und setzte den Wert auf true.

Die WebIDE ersetzt den App Manager. Genau wie im App Manager kannst du mit der WebIDE Firefox OS Apps mithilfe des Firefox OS Simulator oder einem richtigen Firefox OS Gerät ausführen und debuggen.

Darüber hinaus ist es eine vollwertige Entwicklungsumgebung zur Erstellung und Bearbeitung deiner Firefox OS Apps. Sie bietet eine Baumansicht zur strukturierten Anzeige, Bearbeitung und Sicherung aller Dateien deiner App. Für die Erleichterung deines Einstiegs helfen dir zwei App Templates.

In der WebIDE, musst du zuerst ein oder mehrere Laufzeiten erstellen. Eine Laufzeit ist eine Umgebung, in der du deine Apps ausführst und debuggst. Sie ist entweder ein Firefox OS Gerät, welches per USB verbunden ist oder der Firefox OS Simulator.

Als nächstes kannst du eine App erstellen oder öffnen. Wenn du eine neue App öffnest beginnst du mit einem Template, welches bereits das mindeste an Ordnerstrucktur und Code enthält, was du für den Start benötigst. Du kannst auch mit einem umfangreicheren Code Template anfangen, welcher dir Zeigt, wie man mit privilegierte APIs umgeht. Deine App Dateien werden in einer Baumansicht dargestellt und mithilfe des eingebauten Quelleditors kannst du sie jederzeit komfortabel ändern und speichern. Natürlich kannst du auch mit deinem Quelleditor deiner Wahl arbeiten und die WebIDE nur zum debuggen verwenden.

Zum Schluss kannst du deine App in eine der Laufzeiten installieren und ausführen. Ab dann kannst du auch zu den üblichen Entwickler Tools, wie Inspector, Console, JavaScript Debugger und mehr zurückgreifen, um deine laufende App zu prüfen und modifizieren.


Alles was du zum Entwickeln und Debugging mit der WebIDE benötigst ist Firefox Version 33 oder höher. Zum Test deiner App auf einem echten Firefox OS Gerät benötigst du ein Gerät mit min. Firefox OS 1.2 und einem USB Kabel.

Du kannst die WebIDE nur nutzen, wenn du dich auf Firefox OS 1.2 oder höher ausrichtest.

Öffnen der WebIDE

Klick hierzu im Web Entwickler Menü auf den WebIDE Eintrag. Die WebIDE sollte sich öffnen. Alternativ kannst du auch die Tastenkombination Shift-F8 nutzen:The dropdown on the left labeled "Open App" lets you open existing apps or create new ones. The dropdown on the right labeled "Select Runtime" lets you select a runtime or set up a new runtime.

The buttons in the middle run, stop, and debug the app: they are only enabled when you have opened an app and selected a runtime.

Setting up runtimes

Under the "Select Runtime" dropdown, runtimes are grouped into three types:

  • USB devices: Firefox OS devices connected over USB
  • Simulators: instances of the Firefox OS Simulator that you've installed
  • Custom: use this to connect to the WebIDE using an arbitrary name and port.

The first time you click the dropdown, you might not see any runtimes here:

The rest of this section describes how you can add some runtimes.

Connecting a Firefox OS device

Before you can connect a Firefox OS device, there's some setup you have to go through:

  • check your Firefox OS version: make sure your device is running Firefox OS 1.2/Boot2Gecko 1.2 or higher. To check the version, go to the Settings app on the device, then Device Information > Software. If you don't have a high enough version, find your device in the developer phone guide and follow the instructions for upgrading.
  • enable remote debugging: in the Settings app on the device, go to Device information > More information > Developer.
    • Firefox OS 1.3 and earlier: "Remote Debugging" is just a simple checkbox. Check it.
    • Firefox OS 1.4 and later: "Remote Debugging" asks you to enable for just ADB, or for ADB and DevTools. Select "ADB and DevTools".
  • disable Screen lock on your device: in the Settings app on the device, go to Screen Lock and unchecking the Lock Screen checkbox. This is a good idea because when the screen gets locked, the phone connection gets lost, meaning it is no longer available for debugging.
  • if you want to debug certified apps, including built-in apps: see the section on debugging certified apps.

Linux only:

  • add a udev rules file, as documented in step 3 of this guide to setting up an Android device. The idVendor attribute to use for the Geeksphone is "05c6", and this page lists other idVendor values.

Windows only:

If there are any other Android devices connected to your computer, disconnect them. Now connect the device to the computer using USB. You should see the device appear under "USB DEVICES":

If you don't see your device, see the Troubleshooting page.

Adding a Simulator

The Firefox OS Simulator is a version of the higher layers of Firefox OS that simulates a Firefox OS device, but runs on the desktop. It runs in a window the same size as a Firefox OS device, includes the Firefox OS user interface and built-in apps, and simulates many of the Firefox OS device APIs.

This means that in many cases, you don't need a real device to test and debug your app.

The Simulator is big, so it doesn't ship inside Firefox but as a Firefox add-on. If you click "Install Simulator" in the Runtimes dropdown menu, you will go to a page from which you can install Simulators for various versions of Firefox OS.

You can install as many as you like. Be patient, though: the Simulator is large and may take a few minutes to download. Once you've installed some Simulators you can close this "Extra Components" window, and the Simulators you've installed appear as options in the Runtimes dropdown menu:

To learn more about the Simulator, see its documentation page.

Custom runtimes

With a custom runtime you can use an arbitrary hostname and port to connect to the remote device.

Under the hood, Firefox OS devices and Android devices connect to the desktop using a program called the Android Debug Bridge, or ADB. By default, the WebIDE uses an add-on called the ADB Helper: this simplifies the process for you by installing ADB and setting up port forwarding so the Firefox desktop tools can exchange messages with the device.

This is convenient in most cases, but sometimes you might want to use ADB outside of the WebIDE: for example, you might be running ADB directly from the command line. In that case you'll connect to the device by specifying a host and port using the adb forward command.

If you then want to use WebIDE to connect as well, you should disable the ADB Helper add-on and connect WebIDE using the Custom runtime option, entering the host and port that you passed to adb forward.

Also, the ADB Helper does not yet support connecting to Firefox for Android, so if you want to connect WebIDE to Firefox for Android, you'll need to set up your own port forwarding and use a custom runtime. See more about connecting to Firefox for Android using ADB.

Selecting a runtime

Once you've set up a runtime you can select it using the "Select Runtime" menu.

  • If you select a Simulator, the WebIDE launches the Simulator.
  • If you select a Firefox OS device the WebIDE connects to the device. On the device a dialog will ask you to confirm that you wish to connect: press "OK".

Now the "play" button in the center of the WebIDE toolbar is enabled: click it to install and run the app in the selected runtime.

Runtime actions

When a runtime is selected, the Runtimes dropdown menu has three extra items:

  • Runtime Info: information on the current runtime
  • Permissions Table: a table summarising app permissions for the current runtime, indicating, for each API and each app type, whether access is allowed (✓), denied (✗), or whether the user is prompted (!)
  • Screenshot: a command to take a screenshot from the runtime

Creating and opening apps

Under the "Open App" menu you get three options: create a new app, open a packaged app, and open a hosted app:

Create a new app

Select "New App..." to create a new app. You'll see a dialog offering you a choice between two templates, "Privileged Empty App" and "Privileged App".

Both templates are from Mozilla's app template collection, and provide you with the basic structure you need to get started. The "Privileged App" shows how an app can use permissions to load cross-origin content.

Once you've selected a template you'll be asked to name the app and select a directory to store the files, and then the new app is opened in the project editor.

Open a packaged app

Select "Open Packaged App..." to open a packaged app. You'll be asked to select a directory containing the app's manifest, and the app will be opened in the project editor.

Open a hosted app

Select "Open Hosted App..." to open a hosted app. You'll be asked to enter a URL pointing to the app's manifest, and the app will be opened in the project editor.

Editing apps

The project editor provides an environment for editing apps. There's a tree view on the left of all the files in the app: you can add and delete files here using a context menu. There's an editor pane on the right.

The app summary page

When you first open or create an app, the editor pane is occupied by the app summary page, which is shown below:

You can always get back to the app summary page by clicking on the root of the tree on the left.

Manifest validation

The WebIDE automatically checks the manifest for certain common problems. If it finds a problem it indicates that the app is invalid and describes the problem in the app's summary:

Of course, you can edit the manifest.webapp file right in the project editor as well.

The source editor

The WebIDE uses the CodeMirror source editor.

Source editor shortcuts

This table lists the default shortcuts for the source editor.

In the Editor Preferences section of the developer tools settings, you can choose to use Vim, Emacs, or Sublime Text key bindings instead.

To select these, visit about:config, select the setting devtools.editor.keymap, and assign "vim" or "emacs", or "sublime" to that setting. If you do this, the selected bindings will be used for all the developer tools that use the source editor. You need to reopen the editor for the change to take effect.

From Firefox 33 onwards, the key binding preference is exposed in the Editor Preferences section of the developer tools settings, and you can set it there instead of about:config.

Command Windows macOS Linux
Go to line Ctrl + J, Ctrl + G Cmd + J, Cmd + G Ctrl + J, Ctrl + G
Find in file Ctrl + F Cmd + F Ctrl + F
Select all Ctrl + A Cmd + A Ctrl + A
Cut Ctrl + X Cmd + X Ctrl + X
Copy Ctrl + C Cmd + C Ctrl + C
Paste Ctrl + V Cmd + V Ctrl + V
Undo Ctrl + Z Cmd + Z Ctrl + Z
Redo Ctrl + Shift + Z / Ctrl + Y Cmd + Shift + Z / Cmd + Y Ctrl + Shift + Z / Ctrl + Y
Indent Tab Tab Tab
Unindent Shift + Tab Shift + Tab Shift + Tab
Move line(s) up Alt + Up Alt + Up Alt + Up
Move line(s) down Alt + Down Alt + Down Alt + Down
Comment/uncomment line(s) Ctrl + / Cmd + / Ctrl + /

Code completion

When editing CSS and JavaScript, the editor provides autocomplete suggestions. CSS autocompletion is always enabled:

To display autocomplete suggestions in JavaScript press Control + Space:

Inline documentation

The editor also shows inline documentation for JavaScript. Press Shift + Space to see a popup containing documentation for the symbol your cursor is on:

Clicking the [docs] link in the popup will take you to the MDN page for the symbol.

Saving files

For changes to your files to take effect you need to save them. Files with unsaved changes get an asterisk next to their name in the tree view, and you can save files using the menu or Control+S (Command+S on Mac OS X).

Removing projects

To remove an app from the WebIDE, go to the app summary page and click "Remove Project".

Running and debugging apps

When you're ready to run the app, you need to select a runtime from the "Select Runtime" dropdown menu. If you don't have any available runtimes here, find out how to add some in Setting up runtimes.

The "play" button in the center of the WebIDE toolbar is now enabled: click it to install and run the app in the selected runtime:

To debug the app, click the "Pause" button and the Developer Tools Toolbox appears, connected to your app:

Exactly which tools you'll have available depends on the runtime, but you will at least have the basics: the Inspector, Console, JavaScript Debugger, Style Editor, Profiler and Scratchpad. Just as in a web page, any changes you make in the tools are visible immediately in the app, but are not persistent. Conversely, any changes you make in the editor pane can be saved straight back to disk, but are not visible without restarting the app.

Debugging certified apps

With the Simulator, if you click on the app dropdown menu while the runtime is selected, you can see and debug not only your app but all apps running in that runtime, including certified apps:

However, to debug certified apps on a real device:

  • the device must be running a development build of Firefox OS 1.2+
  • you must enable certified app debugging

To enable certified app debugging, connect to the runtime, and then, in the menu, go to Runtime > Runtime Info. From here, if you see "DevTools restricted privileges: yes", that means certified apps can't be debugged. The path then differs depending on what you are debugging against:

  • Real device
    • If it can be rooted, clicking "request higher privileges" will enable certified apps debugging (Firefox OS will restart).
  • Simulator
    • The simulators come with certified debugging enabled by default.
  • B2G desktop
    • Manually edit the B2G desktop client preferences before connecting to enable certified app debugging.

Now (or after a restart of the B2G desktop client) in the WebIDE you should see all the certified apps on the device.

Monitoring performance

If you're interested in the performance of your apps, there are a few ways to measure their impact on the runtime in WebIDE:

  • The Monitor panel offers a good overview of a device's performance. This can help you detect problems, e.g. a sudden, excessive increase in an app's memory usage (leak).
  • The Profiler tool gives you a way to analyze a single app's footprint in great detail. This is especially useful when investigating a known performance problem.


If you have any problems working with the WebIDE, see the Troubleshooting page.