Uncaught ReferenceError: X is not defined

Question

This code is being used on a Chrome Extension. When I call the "showOrHideYT()" function, I get a

"Uncaught ReferenceError: showOrHideYT is not defined | (anonymous function) | onclick"

This code will search for youtube links in a page, and it will add a button (it's really a div with an event) next to the link to show the iframe with the embedded video, pretty much like Reddit Enhancement Suite. Consider the code, per se, incomplete. I just want to know what am i missing when i call the "showOrHideYT(frameZES12345)" function.

if needed, i can provide manifest.json.

Thanks

function showOrHideYT(id)
{
    var YTvidWidth  = 420;
    var YTvidHeight = 315;
    frameYT=getElementById(id);
    console.log(frameYT.style.visibility);
    if (frameYT.style.visibility == "hidden")
        {
        frameYT.style.width = YTvidWidth+"px"; 
        frameYT.style.height = YTvidHeight+"px"; 
        frameYT.style.visibility = "visible";
        }
    if (frameYT.style.visibility == "visible")
        {
        frameYT.style.width = "0px"; 
        frameYT.style.height = "0px"; 
        frameYT.style.visibility = "hidden";
        }
};


// DOM utility functions
function insertAfter( referenceNode, newNode ) {
    if ((typeof(referenceNode) == 'undefined') || (referenceNode == null)) {
        console.log(arguments.callee.caller);
    } else if ((typeof(referenceNode.parentNode) != 'undefined') && (typeof(referenceNode.nextSibling) != 'undefined')) {
        if (referenceNode.parentNode == null) {
            console.log(arguments.callee.caller);
        } else {
            referenceNode.parentNode.insertBefore( newNode, referenceNode.nextSibling );
        }
    }
};
function createElementWithID(elementType, id, classname) {
    obj = document.createElement(elementType);
    if (id != null) {
        obj.setAttribute('id', id);
    }
    if ((typeof(classname) != 'undefined') && (classname != '')) {
        obj.setAttribute('class', classname);
    }
    return obj;
};
/////////////////////////////////////// 



$(document).ready(function() {

    
    var vidWidth    = 420;
    var vidHeight   = 315;
    var linksSemID  = document.getElementsByTagName("a") ;

    for (var i = 0; i < linksSemID.length; i++){
        if (/id=$/.test(linksSemID[i].href)) links[i].href += "1";
    }

    i=0;
    var youTubeRegExp = /(?:v=)([\w\-]+)/g;                 
    var forEach = Array.prototype.forEach;                  
    var linkArray = document.getElementsByTagName('a');     

    forEach.call(linkArray, function(link){                 
        linkArray.id="zes" + i++;                           
        
        var linkTarget = link.getAttribute('href');         
        if (linkTarget!=null)                               
            {
            if (linkTarget.search(youTubeRegExp) !=-1)      
                {
                
                console.log (linkTarget);
                idVideo=linkTarget.match(/(?:v=)([\w\-]+)/g);
                //idVideo = idVideo.replace("v=", "");      
                
                //add buton
                botaoMais = document.createElement('DIV');
                botaoMais.setAttribute('class','expando-button collapsed video');
                botaoMais.setAttribute('onclick','showOrHideYT(frameZES'+ i +')');
                insertAfter(link, botaoMais);

                
                
                //add iframe
                ifrm = document.createElement('IFRAME'); 
                ifrm.setAttribute('src', 'http://www.youtube.com/embed/'+ idVideo); 
                ifrm.style.width = '0px'; 
                ifrm.style.height = '0px'; 
                ifrm.style.frameborder='0px';
                ifrm.style.visibility = 'hidden';
                ifrm.setAttribute('id', 'frameZES' + i);
                insertAfter(link, ifrm);
                
                }
            }
    });  

});

Answer 1

When you use setAttribute with a string, the event will be executed in the context of the page. The functions which are defined in a Content script are executed in a sandboxed scope. So, you have to pass a function reference, instead of a string:

Replace:

    botaoMais.setAttribute('onclick','showOrHideYT(frameZES'+ i +')');

With:

    botaoMais.addEventListener('click', (function(i) {
        return function() {
            showOrHideYT("frameZES"+ i);
        };
    })(i));

Explanation of code:

• (function(i) { ..})(i) is used to preserve the value of i for each event.
• Inside this self-invoking function, another function is returned, used as an event listener to click.