JavaScript Application Cookbook

dhtml.js

Practical use

DHTML layer creation, hiding, and revealing

Version requirement

JavaScript 1.2

Functions

genLayer(), hideSlide(), showSlide(), refSlide()

If you’ve been reading the book in order, you’ve seen this code in two previous applications (the slideshow and the multiple search engine interface). Figures 6-5 and 6-6 show the code that has created a layer and allows you to hide and show it at will.

Figure 6-5. “Eye-catching” DHTML: Now you see it

Figure 6-6. Now you don’t

Example 6.4 shows the contents of dhtml.js. I haven’t changed a thing. Check Chapter 3 and Chapter 5 for the code details.

Example 6-4. dhtml.js

 1 var NN = (document.layers ? true : false); 2 var hideName = (NN ? 'hide' : 'hidden'); 3 var showName = (NN ? 'show' : 'visible'); 4 var zIdx = -1; 5 function genLayer(sName, sLeft, sTop, sWdh, sHgt, sVis, copy) { 6 if (NN) { 7 document.writeln('<LAYER NAME="' + sName + '" LEFT=' + sLeft + 8 ' TOP=' + sTop + 9 ' WIDTH=' + sWdh + ' HEIGHT=' + sHgt + ' VISIBILITY="' + sVis + 10 '" z-Index=' + zIdx + '>' + copy + '</LAYER>'); 11 } 12 else { 13 document.writeln('<DIV ID="' + sName + 14 '" STYLE="position:absolute; overflow:none;left:' + sLeft + 15 'px; top:' + sTop + 'px; width:' + sWdh + 'px; height:' + sHgt + 16 'px; visibility:' ...