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Preloading Images During Page Load Instead Of After

By default, HierMenus will preload its standard images (the more images indicating that a child menu exists for a menu item, or that more choices are available above or below the scrollbar in scrolling menus) just after the HTML page finishes loading, but just before the menus are actually created (dependent on the menu's CreateOnLoad setting, of course). In addition to these standard images, HierMenus will preload at that same time any rollover images that you've designated in the HM_o_RolloverImages object. You can disable this image preload routine by setting the PreloadImages parameter to false in an HM_f_UpdateDefaults call.

In some cases, however, waiting for the page to complete loading to process your image preloads will be too long for your needs. If you would rather have HierMenus preload the standard and rollover images while the page is loading, you can place this command in your configuration file:

if(typeof(HM_f_PreloadImages)!="undefined")
   HM_f_PreloadImages();

This command will process HierMenus' image preload routine immediately, and since the configuration file is processed as part of the page load, the image preloads will happen as part of the page load, too. When you call HM_f_PreloadImages directly in this manner, you will override HierMenus' own image preloading. In other words, whether you've set the PreloadImages parameter to true or false, HierMenus will "see" that you have already processed the image preload manually and will not reprocess the routine on its own.

Note that HierMenus' preload routine uses the image locations as they were specified in HM_f_UpdateDefaults; therefore you should specify the locations of your more images as default settings whenever possible. If specified on the menu or item level only, HierMenus may miss the preloading of these images. If you must specify more images on the menu or item level (perhaps as overrides) and you're having trouble with their display as the result of not having been preloaded, you can always force them to preload by including them explicitely in a HM_o_RolloverImages object in the configuration file. Just set them to "fake" ids (HM doesn't actually care if the ids presented in HM_o_RolloverImages actually exist on the page; it attempts to preload the designated image for them anyways).