JavaScript Forum

**Moldarin** · 08-13-2007, 03:21 PM

Hi,

Code:

<a href="urn:isbn:<isbn>">Book</a>

I want to apply onclick="resolveURI()" to all urn:isbn: links on-load. This function should set window.location="http://www.amazon.com/dp/<ISBN>".

DOM scripting, of course.

**tripy** · 04:17 PM

Are you looking for a hint on how to do it; or for a ready made js code ?

By the way, an onclick won't do in your case. At least not with firefox.
You will need to replace the href, otherwise, you will have the browser telling you that uri: is not a registered protocol.

**Moldarin** · 08-13-2007, 04:28 PM

I am looking for a way to find all urn:isbn: hrefs. There is where my problem lies.

The Firefox issue can be resolved by simply removing the HREF value all together.

**tripy** · 04:41 PM

Ok, I just wanted to check if you where looking for a free freelancer.
Sorry, me just being paranoid.

For that, the most DOM compliant way is to add an event that will scan every tags "a" in the page, and rewrite their href. No need to drop them.

HTML Code:

<html>
  <head>
    <title>dfg</title>
  </head>
  <body>
    <script type="text/javascript">
      function handleUri(){
        var ary=document.getElementsByTagName('a');
        var aryTmp = new Array();
        var isbn=null;
        var i=0;
        for(i=0;i<ary.length;i++){
          if(ary[i].href.indexOf(':isbn:')!=-1){
            //This is an isbn url
            aryTmp=ary[i].href.split(":");
            isbn = aryTmp[2];
            ary[i].setAttribute('href','http://www.amazon.com/dp/'+isbn);
          }
        }
      }

      try{
        window.addEventListener('load',handleUri,true);
      }
      catch(r){
        window.attachEvent('onload',handleUri);
      }
    </script>
    <a href="urn:isbn:<isbn1>">Book</a><br/>
    <a href="urn:isbn:<isbn2>">Book</a><br/>
    <a href="urn:isbn:<isbn3>">Book</a><br/>
    <a href="urn:isbn:<isbn4>">Book</a><br/>
    <a href="http://www.google.com">Not isbn!</a><br/>
  </body>
</html>

Note that here, I consider that the href to handle are always containing ":isbn:", it ignores every other links

**Moldarin** · 02:53 PM

Why did I not get an email notification about your reply? :S That was odd.

Anyhow: Thanks for your code. I will try and make it work a little faster (it was slow, no offence) and post my improvements here.

**tripy** · 08-19-2007, 03:44 PM

It's not that slow, but it depends of the number of links you have.
What you can have seen as slowness is that this script wait for the page to be completely loaded to be run.
So, yes, it can wait a couple of seconds before being run, but if you want to catch every links on the page, there are not that much choices, afaik...

**Moldarin** · 10:12 PM

I stumbled upon upon a possible security whole in Firefox 2 while trying to smarten up your code. (I will of course not discuss the whole. Submitted it to Mozilla.) However I was not able to make the code work any faster. BUT when I restarted my computer and ran your code again; it magically worked instantaneous! I have no idea why.

I will rely on your code for URN resolution until Internet 2 is available for everyone!

Thanks for the help tripy.

**chrishirst** · 08-23-2007, 05:11 AM

Quote:

BUT when I restarted my computer and ran your code again; it magically worked instantaneous! I have no idea why

It's because (being client side code) it runs as fast as the browser will let it. If your browser has already used a lot of resources then it will be slow, as it tries to use even more resources when reading the page in memory.