mirror of
https://github.com/mdn/webextensions-examples.git
synced 2026-04-17 14:59:12 +02:00
34 lines
2.8 KiB
Markdown
34 lines
2.8 KiB
Markdown
This is a very simple example of how to use [native messaging](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Native_messaging) to exchange messages between a WebExtension and a native application.
|
|
|
|
The WebExtension, which can be found under "add-on", connects to the native application and listens to messages from it. It then sends a message to the native application when the user clicks on the WebExtension's browser action. The message payload is just "ping".
|
|
|
|
The native application, which can be found under "app", listens for messages from the WebExtension. When it receives a message, the native application sends a response message whose payload is just "pong". The native application is written in Python.
|
|
|
|
## Setup ##
|
|
|
|
To get this working, there's a little setup to do.
|
|
|
|
### Mac OS/Linux setup ###
|
|
|
|
1. Check that the [file permissions](https://en.wikipedia.org/wiki/File_system_permissions) for "ping_pong.py" include the `execute` permission.
|
|
2. Edit the "path" property of "ping_pong.json" to point to the location of "ping_pong.py" on your computer.
|
|
3. copy "ping_pong.json" to the correct location on your computer. See [App manifest location ](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Native_messaging#App_manifest_location) to find the correct location for your OS.
|
|
|
|
### Windows setup ###
|
|
|
|
1. Check you have Python installed, and that your system's PATH environment variable includes the path to Python. See [Using Python on Windows](https://docs.python.org/2/using/windows.html). You'll need to restart the web browser after making this change, or the browser won't pick up the new environment variable.
|
|
2. Edit the "path" property of "ping_pong.json" to point to the location of "ping_pong_win.bat" on your computer. Note that you'll need to escape the Windows directory separator, like this: `"path": "C:\\Users\\MDN\\native-messaging\\app\\ping_pong_win.bat"`.
|
|
3. Edit "ping_pong_win.bat" to refer to the location of "ping_pong.py" on your computer.
|
|
4. Add a registry key containing the path to "ping_pong.json" on your computer. See [App manifest location ](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Native_messaging#App_manifest_location) to find details of the registry key to add.
|
|
|
|
## Testing the example ##
|
|
|
|
Then just install the add-on as usual, by visiting about:debugging, clicking "Load Temporary Add-on", and selecting the add-on's "manifest.json".
|
|
|
|
You should see a new browser action icon in the toolbar. Open the console ("Tools/Web Developer/Browser Console" in Firefox), and click the browser action icon. You should see output like this in the console:
|
|
|
|
Sending: ping
|
|
Received: pong
|
|
|
|
If you don't see this output, see the [Troubleshooting guide](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Native_messaging#Troubleshooting) for ideas.
|