January 24, 2001 - Extending getSrc() to Mozilla Browsers | WebReference

January 24, 2001 - Extending getSrc() to Mozilla Browsers

Yehuda Shiran January 24, 2001
Extending getSrc() to Mozilla Browsers
Tips: January 2001

Yehuda Shiran, Ph.D.
Doc JavaScript

DOCJSLIB 1.0 includes three functions:

makeImage() creates an IMG element within a DIV element.
  • getSrc() returns the image's URL.
  • setSrc() sets the image's URL.

    To adapt getSrc() to Netscape 6 and Internet Explorer 5.x, we need to use document.getElementByID instead of document.all and document.id. Here is the old version:

    function getSrc(id) {
  if (NS4) {return eval("document." + id + ".document." + id + "img.src")}
  else {return eval("document.all." + id + "img.src")}
}

    and here is the new version that supports both Netscape 6 and IE5.x:

    function getSrc(id) {
  if (NS4) {return eval("document." + id + ".document." + id + "img.src")}
  else if (IE4) {return eval("document.all." + id + "img.src")}
       else if (IE5 || N6) {return document.getElementById(id + "img").src};
}

    The convention used in DOCJSLIB is that if a DIV element is labeled with a given ID, the ID of the IMG element within the DIV element is a concatenation of ID and the string "img". If the DIV's ID is "foo", for example, the IMG element within it will be labeled "fooimg". This is the reason we search above an IMG element that has an ID of id + "img".

    The different browsers are detected via the following code:

    var IE4 = (document.all && !document.getElementById) ? true : false;
var NS4 = (document.layers) ? true : false;
var IE5 = (document.all && document.getElementById) ? true : false;
var N6 = (document.getElementById && !document.all) ? true : false;