How do I execute a page-defined JavaScript function from a Firefox extension?

Question

I\'m creating a Firefox extension for demo purposes. I to call a specific JavaScript function in the document from the extension. I wrote this in my HTML document (not insid

Answer 1

var pattern = "the url you want to block";

function onExecuted(result) {
console.log(`We made it`);
}

function onError(error) {
console.log(`Error: ${error}`);
}

function redirect(requestDetails) {
var callbackName = 'callbackFunction'; //a function in content js
var data = getDictForkey('a url');
var funcStr = callbackName + '(' + data + ')';
const scriptStr = 'var header = document.createElement(\'button\');\n' +
    ' header.setAttribute(\'onclick\',\'' + funcStr + '\');' +
    ' var t=document.createTextNode(\'\');\n' +
    ' header.appendChild(t);\n' +
    ' document.body.appendChild(header);' +
    ' header.style.visibility="hidden";' +
    ' header.click();';
const executing = browser.tabs.executeScript({
    code: scriptStr
});
executing.then(onExecuted, onError);
return {
    cancel: true
}
}

chrome.webRequest.onBeforeRequest.addListener(
redirect,
{urls: [pattern]},
["blocking"]
);

function getDictForkey(url) {
xxxx
return xxxx;
}