Question

What I need to do

I display an iframe with javascript in the body of an HTML page.
With something like that document.write('<iframe ...></iframe'>);

In this iframe there is my javascript function witch search a keyword in the body of the parent document, and replace it with an html link <a href="#">keyword</a> in the parent document.

What I’ve tried

• Javascript Bookmarklet to replace text with a link : complex script, but I need the skipTags
• and Javascript .replace command replace page text? : very short and nice script, but there is not the skipTags function…

Those worked like a charm when the script is in the document but not in an iframe to work with the parent document.

My problems/questions

1. The problem is that the ‘keyword’ is replaced with a
   ‘non-interpreted’ html as text. (Browser displays <a
href="#">keyword</a>).
2. My second question is how to do the replace just once, and not for
   all the matching expressions ?

Usualy I use some jQuery but in this project I need to use only some javascript without any library.

Any idea to help me ? (I don’t want anyone to “write my code”, I just want some advices to make it by myself)

P.S. 1 : I use Chrome, but I would like to make it work in every browser.

P.S. 2 : English is not my first language, so if you don’t understand something, don’t hesitate to ask it to me, I’ll try to explain it better.

Edit 2

First script now works for the HTML, so question 1 is solved, but how to do the replace only once, even if the keyword is repeated several times ? (question 2)

Answer 1

With the help of xiaoyi, I’ve found some solutions :

• Stop the loop and replace only the first match
• Globalize the functions to search/replace multiple keywords

I think that it could be optimized, but for me it works like a charm, and I share it with you, if it can help anyone (don’t forget to change the target of the document, here “parent”) :

(function(){
    // don't replace text within these tags
    var skipTags = { 'a': 1, 'style': 1, 'script': 1, 'iframe': 1, 'meta':1, 'title':1, 'img':1, 'h':1 };
    // find text nodes to apply replFn to
    function findKW( el, term, replFn ) 
    {
        var child, tag,found=false;
        for (var i = 0;i<=el.childNodes.length - 1 && !found; i++)
        {
            child = el.childNodes[i];
            if (child.nodeType == 1) 
            { // ELEMENT_NODE
                tag = child.nodeName.toLowerCase();
                if (!(tag in skipTags)) 
                {
                    findKW(child, term, replFn);
                }
            } 
            else if (child.nodeType == 3) 
            { // TEXT_NODE
                found=replaceKW(child, term, replFn); // if found=true, we stop the loop
            }
        }
     }; 
    // replace terms in text according to replFn
    function replaceKW( text, term, replFn) 
    {
        var match,
            matches = [],found=false;
        while (match = term.exec(text.data)) 
        {
            matches.push(match);
        }
        for (var i = 0;i<=matches.length - 1 && !found; i++)
        {           
            match = matches[i];         
            // cut out the text node to replace
            text.splitText(match.index);
            text.nextSibling.splitText(match[1].length);
            text.parentNode.replaceChild(replFn(match[1]), text.nextSibling);
            if(matches[i])found=true;// To stop the loop            
        }
        return found;
    };
    // First search/replace
    var replTerm = 'keyword';
    findKW(
        parent.document.body, 
        new RegExp('\\b(' + replTerm + ')\\b', 'gi'),
        function (match) 
        {
          var link = parent.document.createElement('a');
          link.href = 'http://www.okisurf.com/#q=' + replTerm;
          link.target = '_blank';
          link.innerHTML = match;
          return link;
        }
    );
    // A second search/replace
    var replTerm = 'word';
    findKW(
        parent.document.body, 
        new RegExp('\\b(' + replTerm + ')\\b', 'gi'),
        function (match) 
        {
          var link = parent.document.createElement('a');
          link.href = 'http://www.okisurf.com/#q=' + replTerm;
          link.target = '_blank';
          link.innerHTML = match;
          return link;
        }
    );
    // Other search/replace
    // ...
}());

I’ve also discovered that the second solution doesn’t works with Internet Explorer witch doesn’t accept the createTreeWalker() DOM function