Question

I saw a piece of code like this:

var pl = document.createElement('tr');
...
pl.file = f;
pl.onclick = function(e){
    if(e && e.button == 1){
        pl.parentNode.removeChild(pl);
    }else{
        var url;
        if(window.createObjectURL){
            url = window.createObjectURL(f)
        }else if(window.createBlobURL){
            url = window.createBlobURL(f)
        }else if(window.URL && window.URL.createObjectURL){
            url = window.URL.createObjectURL(f)
        }else if(window.webkitURL && window.webkitURL.createObjectURL){
            url = window.webkitURL.createObjectURL(f)
        }                      
        $("player").src = url;
        $("player").play();
    }
}

It’s for a audio player. And I was thinking if tr element have a file attribute? I was searched the internet but got nothing.

Answer 1

No, the <tr> element does not have a file attribute. This means you shouldn’t write the following (invalid) HTML:

<tr file="http://example.com/file.txt">

You can do something very close to that in HTML5 using data-file as the attribute’s name, then it’s valid.

<tr data-file="http://example.com/file.txt">

But you don’t have that on your markup (presumably), you’re just taking a JavaScript object that represents that <tr>, and adding it a property – not an attribute. To manipulate an actual attribute (like data-file), you’d have to use setAttribute and getAttribute.