Sam wrote:
Using Ajax, if I wanted to preload several (20) small (<1K) images,
behind the scenes... would I...
Why not just use the Image object that is built into all browsers. I
guess to say wouldn't it just be easy to use the image preloading
techniques used for years?
If you don't have a simple list of image files but instead have a HTML
fragment that contains the images you are looking for take a look at the
script here:
http://afaik.us/element_rotate/element_rotate.js
Towards the bottom I extend the "String.prototype" object so that you
can preload any images that are located in a HTML string fragment. So:'
htmlFragment = "<b>Here is a <img src="fragment.gif" /> html fragment</b>";
htmlFragment.preloadImgs();
Feel free to rip out these utility functions for your own purposes. Also
if you have lots of small images you may want to look into loading only
one image which contains all your images. This technique is used often
by complex widgets such as WYSIWYG editors. See:
http://tinymce.moxiecode.com/tinymce/docs/option_button_tile_map.html
which talks about that option for the TinyMCE editor. Obviously see the
source code for that project for implementation details. This technique
can greatly increase the load time because you are greatly reducing the
number of HTTP requests. It also gives good feedback to the user because
all the images load at once instead of having to watch them load one-by-one.
Eric
_______________________________________________
Rails-spinoffs mailing list
Rails-spinoffs@lists.rubyonrails.org
http://lists.rubyonrails.org/mailman/listinfo/rails-spinoffs
