Question

The following code snippet is needed to capture html links for my site. Although, it seems to work, I wish to have an explanation so that I may improve upon it. Can someone give me a quick summary of what’s happening in this code? I don’t especially understand the while statement that uses this variable ‘link’. What is ‘link’? A dummy variable of some sort like you would use in a dictionary or map iteration? Also, why use document.links[0]?

 if (document.links){
  if (document.links[0]){
   var links = document.links, link, k=0;
   while(link=links[k++]) {
    link.onclick = linkCapture;
   }
  }
 }

function linkCapture() {
  this.parent = this.parentNode;
  eventCapture('Link Click','Page Tag',this.name,this.href);
}

Answer 1

 if (document.links){

The browser supports the property:

  if (document.links[0]){

There is at least one link:

   var links = document.links, link, k=0;

Standard initialization

   while(link=links[k++]) {

For every run through the loop, set link to the next element, then increment k. Exit the loop when the current links[k] is falsy (probably because we’ve passed the last element).

    link.onclick = linkCapture;

Set the onclick property to linkCapture.

This really isn’t great code to begin with. You could write the whole thing using jQuery like:

$(document.links).click(linkCapture);

As a bonus, you wouldn’t risk overwriting an existing onclick property.