Is it possible to call SingleFile from an extension?

[silarri]

I'm trying to call the SingleFile extension from a custom button that performs several actions that are typical in my workflow. My code in the background.js file is as follows:

  const targetExtensionID = "{531906d3-e22f-4a6c-a102-8057b88a1a63}";
  await browser.runtime.sendMessage(targetExtensionID, { action: "ACTION_SAVE_PAGE" })
    .then(response => {
      // Handle the response from the other extension if needed
      recordLog("Received response from SingleFile extension: " + response);
    })
    .catch(error => {
      // Handle any errors that may occur
      recordError("Error sending message to SingleFile extension: " + error);
    });

When I execute that code, I get the message "Received response from SingleFile extension: undefined", but nothing seems to happen. Any idea of what could be failing here?

It seems that the message is correctly sent to the SingleFile extension, as if I change the targetExtensionID then I get an error "Error sending message: Error: Could not establish connection. Receiving end does not exist.". This also begs another question: the target extension ID seems to be quite arbitrary (it is not even set in the manifest.json file of SingleFile, as far as I understand), so the code above seems to be quite fragile (it depends on an ID that has no meaning for me and could change). Any idea about whether this can be managed in a better way is welcome.

Any tip would be great!

[gildas-lormeau]

I would be curious to know where you found that { action: "ACTION_SAVE_PAGE" } was a valid message. You can find the valid values in the help page of the extension or here: #1186 (comment). Note that the message is not an object, it's just a string.