Can the manifest file be dynamic in Chrome Apps? - google-chrome

Question

I am writing a Chrome App that communicate with a web page. For that I have added something similar in my manifest file.
"externally_connectable": {
"matches": ["*://*.example.com/*"]
}
But the "example.com" has to be dynamic as individual customers has their one web server.
Is there any possibility, user(who install the app) can change the externally_connectable site/s.

Answer 1

There is an alternative way a web page can communicate with extension through content script. This approach can be used if both web page and extension are done by you.
E.g.
web page <--> content script of extension <--> background script of
extension <--> native application
For web page to content script of extension communication use window.postMessage and window.addEventListener
For Google Chrome browser,
For content script of extension to background script of extension communication use chrome.runtime.sendMessage and chrome.runtime.onMessage.addListener
For background script of extension to native application communication use chrome.runtime.sendNativeMessage
Please make sure your code has necessary security in place.

Answer 2

As far as I know the "externally_connectable" is the only official way to send messages (With data) from a web page as mentioned here
This requires a predefined values for every single domain. But what if you want to make only one extension to accept messages from any web page?
If you just want to notify the other side about some thing, you can use the native JS Event dispatching it on the document from one side and listening to it at document also from the other side as the document is shared between the extension content script pages and the web page.
You can't use JS CustomEvent to send data as every time you send data, you receive it empty as a result of sandbox effect of any extension.
If you want to share data so the only workaround I know so far - after spending about one month developing an extension - is to have a combination between some sort of a storage and the JS native Event mechanism.
The solution in steps (suppose you need the web page to send some data to the extension):
Make an event on document from the web page.
Save the data temporarily inside any storage technology you prefer
(localStorage, the DOM itself, or what ever..)
Receive the event at the other side (extension) by listening on the
document.
Read data and remove it.
Hope this helps someone or open a door for a discussion on a better way doing this.