Xan's comment did the trick.
While Chrome did not complain about *://localhost/*
, it did not work. Chrome did complain about other combinations such as file://localhost/
.
I added foo.com to host file and then served up my web page through a web server, and it worked! I can communicate from my web page to my packaged app.
Note that browsing to file://www.foo.com/hostpage.html did not work. But browing to http://www.foo.com:3000/hostpage.html did. (I'm using Rails, hence the 3000 port).
Morale of the story: When testing locally, you need to add an entry with a bogus second level domain to your host file.
Here's my manifest.json:
{
"name": "RFID Tag Reader",
"description": "Reads RFID Tags connected via USB reader",
"version": "0.0.0.1",
"app": {
"background": {
"scripts": ["background.js"]
}
},
"icons": {
"16": "rfid-16.png",
"128": "rfid-128.png"
},
"permissions": [
"serial",
"*://www.foo.com/*",
"*://arealsite.net/*"
],
"externally_connectable": {
"matches": [
"*://www.foo.com/*",
"*://arealsite.net/*"
]
}
}