CODEWITHSUNDEEP
google-chrome-extension
paradozx
paradozx

Reputation: 108

Problems accessing Google extension function from another extension

As the title states, is it possible to access the methods defined in a google extension from another google extension? The method I am trying to access can be called from the Google Console, however, when I try to access the method from my background page with the following code

chrome.tabs.executeScript(ns.tracsCopyFromTabId, {
            code: "alert(methodName)"  
        }

it gives me the following error:

Unchecked runtime.lastError while running tabs.executeScript: Cannot access a chrome-extension:// URL of different extension

I believe the method I'm trying to access is defined in their content-script? Has anyone ever tried and successfully do this?

Upvotes: 1

Views: 276

Answers (1)

Xan
Xan

Reputation: 77531

The error

The error + your comment about not needing to change the context signifies that you're probably not actually injecting in a regular webpage that runs content scripts, but into an extension page (with visible URL chrome-extension://...).

Anything in such a page is not a content script by definition. Even if that code is also shared with a content script used somewhere else.

Note that if you're using (but not showing) allFrames: true for injection, you may be accidentally injecting in an extension-page frame, leading to that error.

Non-content script code

The problem is that you can't declare host permissions for chrome-extension:// pages. Therefore you can't inject content scripts into those pages.

It's not possible to define permissions to do that from an extension alone (to make an extension you can distribute that "just works"), but you can do it locally with Chrome flags + chrome.debugger API.

You will need chrome://flags/#silent-debugger-extension-api enabled and will need to use the Debugger Protocol to execute your code.

Sadly, the chrome://flags/#extensions-on-chrome-urls flag does not allow injection into this protocol either, so you have to use Debugger.

Content script code

If you're actually trying to reach code in a content script in a regular webpage, you can't call it from your own content script because every extension gets its own isolated JS context.

You'd need chrome.debugger again.

Code injected in the page context

Sometimes you're dealing with code that's injected in the webpage itself from a content script.

Then you should be able to access it with the method you describe by making the same content script -> page code leap. See the link above.

That doesn't explain the error you're getting though.

Upvotes: 1

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