mirror of https://github.com/mdn/webextensions-examples.git synced 2026-04-16 06:18:35 +02:00

Files

Rob Wu 3870a213bb Fix value check in page-to-extension-messaging example (#229 )

Check the value of "event.data" before dereferencing it,
to avoid errors when void messages are sent using postMessage.

And remove the "event.data.direction" truthness check, because the
actual value is already tested at the next line.

2017-06-08 08:06:34 -07:00

icons

use the right size icons

2016-01-14 11:25:15 -08:00

content-script.js

Fix value check in page-to-extension-messaging example (#229 )

2017-06-08 08:06:34 -07:00

manifest.json

Remove applications key wherever possible (#144 )

2016-11-18 14:14:25 -08:00

README.md

Added missing README files and updated some existing ones

2016-02-19 13:19:10 -08:00

README.md

page-to-extension-messaging

What it does

This extension includes a content script, which is injected only into: "https://mdn.github.io/webextensions-examples/content-script-page-script-messaging.html".

The content script listens for clicks on a particular button on the page. When the button is clicked, the content script sends a message to any scripts running in the page.

Conversely, the content script listens for messages from the same window posted using window.postMessage. When the content script receives such a message, it displays an alert.

To test it out, visit https://mdn.github.io/webextensions-examples/content-script-page-script-messaging.html and press the buttons. One button sends a message from the page script to the content script, the other button sends a message in the other direction.

What it shows

How to exchange messages between an extension's content scripts, and scripts running in a web page.