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wml::des::preload(3) EN Tools wml::des::preload(3)

NAME

wml::des::preload - Preload Images

SYNOPSIS

 #use wml::des::preload

 <preload src=<image filename> via=<trick>>

DESCRIPTION

This include file provides the "<preload>" tag which can be used to preload images. Such preloading is usually done to speedup access for following pages. Currently there are only a few tricks how this can be done.

The following combinations are currently supported:

"src="anyimage "via=size"
Preloads the image anyimage by using an "<img>" tag with the attributes "width=1 height=1" which leads to the loading of the image but only to a 1 pixel in display.

Advantage: Works for all browsers.

Disadvantage: This approach has the nasty side-effect of an occurring 1 pixel in display because "width=0 height=0" does not work as expected in most browsers (especially in Netscape 4.x). So, position your "<preload>" tag somewhere it does not destroy the look and feel of your page.

"src="anyimage "via=js"
Preloads the image anyimage by using a JavaScript snippet which loads the image by declaring an unused "Image" object.

Advantage: Silently preloads the image without displaying anything.

Disadvantage: Only works for browsers with a JavaScript implementation and only for those who support the "Image" object (currently NS/3, NS/4, IE/4).

AUTHORS

 Ralf S. Engelschall
 rse@engelschall.com
 www.engelschall.com

 Denis Barbier
 barbier@engelschall.com

REQUIRES

 Internal: P1, P2
 External: --

SEE ALSO

wml::std::tags(3) HTML 3.2 "<img>" tag.
2021-05-25 EN Tools