将HTML转换为document.write javascript

Question

I've see a web page that when I try to view the source, I only see a single JavaScript statement. I searched and could not figure out how they have done that. you can do and see yourself.

The web page is: Weird Page

when I view the source I only see something like below which also looks like a comment:

<script type='text/javascript' language='Javascript'>
<!--document.write(unescape('%3C%2........................
................

How they have done that? How I can change my web page so when someone view the source it look like that?

Answer 1

This article may help to clarify what's happening there.

Basically, this company has encoded their entire page using standard escape characters. If you copy the bit from unencode(...) all the way to the next to last parens, and paste it into your browser console, you'll see the actual HTML content.

If you look at the source code for the page I linked, you'll see the function that converts normal text to all escape characters:

// CONVERTS *ALL* CHARACTERS INTO ESCAPED VERSIONS.
function escapeTxt(os){
    var ns='';
    var t;
    var chr='';
    var cc='';
    var tn='';
    for(i=0;i<256;i++){
        tn=i.toString(16);
        if(tn.length<2)tn="0"+tn;
        cc+=tn;
        chr+=unescape('%'+tn);
    }
    cc=cc.toUpperCase();
    os.replace(String.fromCharCode(13)+'',"%13");
    for(q=0;q<os.length;q++){
        t=os.substr(q,1);
        for(i=0;i<chr.length;i++){
            if(t==chr.substr(i,1)){
                t=t.replace(chr.substr(i,1),"%"+cc.substr(i*2,2));
                i=chr.length;
            }
        }
    ns+=t;
    }
    return ns;
}

Answer 2

What is happening is pretty much what it sounds like. The server is serving a single <script> element, which contains an HTML comment to make it easier for browser that don't support JS (read more here: Why does Javascript ignore single line HTML Comments? ), and in the comment it's writing to the document the unescaped version of the string, which is sent escaped.